IDENTIFICATION OF SUITABLE RICE HYBRIDS ADAPTABLE TO AEROBIC CONDITION. M.Sc. (Ag.) Thesis. Neha Dhirhe

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1 IDENTIFICATION OF SUITABLE RICE HYBRIDS ADAPTABLE TO AEROBIC CONDITION M.Sc. (Ag.) Thesis by Neha Dhirhe DEPARTMENT OF GENETICS AND PLANT BREEDING COLLEGE OF AGRICULTURE RAIPUR FACULTY OF AGRICULTURE INDIRA GANDHI KRISHI VISHWAVIDYALAYA RAIPUR (C.G.) 2017

2 IDENTIFICATION OF SUITABLE RICE HYBRIDS ADAPTABLE TO AEROBIC CONDITION Thesis Submitted to the Indira Gandhi Krishi Vishwavidyalaya, Raipur by Neha Dhirhe IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science in Agriculture (Genetics and Plant Breeding) U. E. ID NO ID No July, 2017

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7 TABLE OF CONTENTS CHAPTER PARTICULARS/TITLE PAGE ACKNOWLEDGEMENT i-ii TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF ABBREVIATIONS ABSTRACT iii-iv v-vi vii viii ix xii I INTRODUCTION 1-3 II REVIEW OF LITERATURE Identification of restorer and maintainer lines Heterosis Combining ability III MATERIALS AND METHODS Experimental site Meteorological data Experimental materials Methods Statistcal analysis Identification of restorers and maintainer lines Heterosis Combining ability analysis 42 IV RESULTS AND DISCUSSION Mean performance of genotypes Mean performance of parents Mean performance of hybrids Identification of restorers and maintainer lines 4.3. Analysis of variance 4.4.Combining ability iii

8 4.4.1 Analysis of variance for line tester GCA and SCA variance Combining ability analysis for GCA and SCA effects Heterosis V SUMMARY AND CONCLUSIONS REFERENCES APPENDIX RESUME 188 iv

9 LIST OF TABLES TABLE PARTICULARS PAGES 3.1 Weekly meteorological observations during crop period Details of parents used in the study List of characteristics, taken under investigation Mean performance of parents for different characters (a) Mean performance of parents for different agro-morphological characters (b) Mean performance of parents for different quality characters Mean performance of hybrids for different characters (a) Mean performance of hybrids for different agromorphological characters (b) Mean performance of hybrids for different quality characters List of identified Restorers and Maintainers Analysis of variance for different characters Analysis of variance for different agromorphological characters Analysis of variance for different quality characters Analysis of variance for line tester General combining ability effects of parents for different characters General combining ability effects of parents for different agro-morphological characters General combining ability effects of parents for different quality characters 4.6 Specific combining ability effects of hybrids for different characters Specific combining ability effects hybrids of for different agro-morphological characters Specific combining ability effects of hybrids for different quality characters v

10 4.7 Mid parent heterosis, Heterobeltiosis and Standard heterosis for different characters Mid parent heterosis, Heterobeltiosis and Standard heterosis for different agro-morphological characters Mid parent heterosis, Heterobeltiosis and Standard heterosis for different quality characters 4.8 Promising hybrids based on mean performance, heterosis and Combining ability for grain yield per plant vi

11 LIST OF FIGURES FIGURE NO. PARTICULARS PAGE NO. 3.1 Weekly meteorological data recorded 29 during the crop season (18 June to 18 November 2016) 4.3 Frequencies of different fertility classes based on pollen fertility and spikelet fertility 85 vii

12 LIST OF ABBREVIATIONS ABBREVIATION DESCRIPTION % Percent ANOVA Analysis of Variance BP Better Parent CD Critical Difference Cm Centimeter CMS Cytoplasmic male sterile df Degree of freedom et.al. And co-worker/ and others E Environment Fig. Figure g Gram GCA General combining ability h 2 Heritability ha Hectare i.e. That is Kg Kilogram L T Line Tester m 2 Square meter mm Milli meter MP Mid parent No. Number q Quintal RCBD Randomized Complete Block Design SCA Specific combining ability TGMS Temperature sensitive genetic male sterility viz., Namely WA Wild Abortive viii

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17 CHAPTER - I INTRODUCTION Rice (Oryza sativa L.) is the world s largest cultivated food crop. Rice is a member of family Poaceae and finds its home in South-East Asia and Asia, where more than 90% of world s rice is produced and consumed (Li and Xu, 2007). Rice is a main staple food for more than 50% of the world population and forms the staple diet of about 2.7 billion people and it needs to be produced 50% more than what is produced now by 2050 to overcome with the growing demand (Ashikari et al., 2005). A major part of rice production is produced and consumed in Asia (Fageria, 2001). China and India are major rice-producing and consuming countries. The global production of rice has been estimated to be at the level of million tonnes and the area under rice cultivation is estimated at million hectares (FAO STAT, 2015). India has the largest area of 45 million ha. for cultivation and ranks second in production next to China with a production of 84.5 million tonnes in an area of 56 million hectares. Almost 25 per cent of the world s rice is grown under rainfed lowlands and frequently affected by uneven rainfall distribution. Another 13 percent of the rice area under cultivation is always subjected to water stress during the growing season. (Bouman et al., 2007). Chhattisgarh (C.G.) the south east central state is also called the Rice bowl of India. Total area of rice in C.G. is 3.80 million ha, production is 6.32 million tonnes and productivity is 1660 kg/ha in (Anonymous, 2015). However, even though rice is an important food source for many millions of people, it is also the single largest user of water, requiring two to three times more water input (rain, irrigation) per unit of grain produced than the major cereal crops, such as wheat and maize. More irrigated land is devoted to rice than to any other crop. With the growing population, increased urbanization and environmental degradation, the supply of fresh water for all human activities is depleting and the situation is getting rapidly worse. For example, it has been estimated that by 2025, 15 million ha. of irrigated rice will suffer physical water scarcity and most of the 22 million ha. of irrigated dry season rice grown in South and South east Asia will suffer economic water scarcity (Tuong and 1

18 2 Bouman, 2002). Most of the world s rice production comes from irrigated and rainfed lowland rice fields. Therefore, the development of new rice cultivation techniques and cultivars are required to reduce water consumption in rice production systems. Various field techniques to save irrigation water have been explored. They include direct seeding, keeping the soil saturated and alternate wetting and drying system (AWD) in lowland fields. (Bouman and Tuong, 2001) reported that, compared with continuously flooded conditions, small yield reductions (0 to 6 per cent) occurred under saturated conditions, but larger reductions (10 to 40 per cent) occurred under AWD, when soil water potential (SWP) during dry phase reached values between 10 and 40 kpa. Therefore, in order to sustain and to increase the rice production to meet the future demands with limited water supplies, there is a need to genetically alter the basic water requirements of rice through breeding techniques (Kumar et al., 2006). Aerobic rice is one such option to decrease water requirements in rice production. Aerobic rice is a production system in which especially developed aerobic rice varieties are grown in well-drained, non-puddled and non-saturated soils. The increasing scarcity of water threatens the sustainability of the irrigated rice production system. Hence, alternate way of rice cultivation (aerobic rice) with less water and without compromising yield has been evolved and popularized. This requires suitable variety or hybrid development with standardization in cultivation practices for rice under minimum water available. Hybrids play an important role in enhanced yield production by heterosis breeding. Developing rice hybrids for both aerobic and drought prone situation is extremely essential to maintain the yields of rice for the present and the near future to keep the rice production sustainable for the growing population with the available depleting water resources. Hybrid rice is practically feasible and readily adoptable genetic option to increase rice production and has been amply demonstrated in China and India. The yield advantage observed at field level is in the range of percent over the best inbred check varieties of corresponding duration under irrigated ecosystem (Virmani and Edwarda, 1983).

19 3 Restorers, which possess nuclear genes (Rf) that restore the fertility of CMS lines, is essential. Conventionally, restorers are identified by test-crossing a large number of genotypes with CMS lines and then evaluating their progeny for pollen and spikelet fertility. Heterosis the increased vigor of growth, survival and fertility of hybrids, as composed with the two homozygotes; it usually results from crosses between two genetically different, highly inbred lines. Performance of a F 1 hybrid depends on choice of parents. Several methods like per se performance, genetic diversity, combining ability etc., have been attempted to select the parents. Among them combining ability analysis offers a powerful tool for estimating the value of a parent to produce superior hybrid. There are two types of combining ability effects. It is also necessary to assess the genetic potential of parents in hybrid combination through systematic studies in relation to both general and specific combining abilities, which could be attributed to additive and non-additive components of gene action, respectively. Among the several statistical tools available to detect the combining ability and gene action governing various quantitative traits, line tester analysis has been a very useful design. In the scenario of water scarce situation for rice production and to keep the rice production sustainable there is a need to develop hybrids for aerobic condition. Hence the present investigation Identification of suitable rice hybrids adaptable to aerobic condition was carried out to identify best combining parents and hybrids suitable for aerobic cultivation. Keeping the above points in consideration, the present investigation has been formulated with the following objectives:- 1. To identify restorers and maintainers. 2. To estimate magnitude of heterosis for yield and quality traits under aerobic condition. 3. To estimate the General and Specific combining ability for yield and quality traits under aerobic condition.

20 CHAPTER-II REVIEW OF LITERATURE Hybrid rice technology appears to be the most feasible and readily adoptable to increase the yield level in rice. Extensive research work is going on throughout India and abroad on different aspects of hybrid rice i.e. combining ability analysis and heterosis genetic. The available pertinent literature has been reviewed for a complete understanding of the subject under following heads: 2.1 Identify restorers and maintainers 2.2 Heterosis 2.3 Combining ability 2.1 Identify restorers and maintainers Cytoplasmic genetic male sterility is controlled by the interaction of cytoplasmic and nuclear genes and was first discovered by Jones and Emsweller (1936) in onion crop. The role of cytoplasm causing male sterility in rice was first reported by Sampath and Mohanty (1954). Hybrid rice breeding programme exploits the phenomenon of heterosis. Hybrid rice can be produced by two breeding approaches viz., three line system of heterosis breeding [cytoplasmic genetic male sterility system (CGMS)] and two line system of breeding. However, in India until now the hybrid rice varieties which have been released are examples of three-line breeding. In three line breeding system, the sterility and/or fertility is due to interaction of nuclear gene with cytoplasm. Two sources of cytoplasm are generally used i.e. Wild Abortive (WA) and Kalinga Ι. The three lines, the A line has sterile cytoplasm, hence A line is sterile and B is an isogenic line of A with the difference of only having fertile cytoplasm. The third line, R line is a restorer line which restores the fertility of A line. In hybrid seed production A line is crossed with R line. In CMS line development programme it is essential to identify effective restorer and maintainer lines for developing commercial rice hybrids. Some of the work related to identification of maintainers and restorer lines is as below: 4

21 5 Sutaryo (1989) identified Bahbolon, Cimanuk, Batang pane, Citanduy, Ciliwung and Bogowonto as restores and Bahbutong, Adil, Cisokan and S397b40-2 as putative maintainers for V20A male sterile line. The 18 effective maintainers identified against three exotic cytoplasmically male sterile (CMS) lines of wild abortive (WA) origin by Kumari et al. (1997). Similarly Ganesan et al. (1998) reported nine genotypes as potential maintainers for cytoplasmically male sterile (CMS) lines of wild abortive (WA) origin. Borkakari and Chetia (2000) identified the Mahsuri and Aghuni as maintainers for IR58025A. Anand et al. (2002) reported Gautam, Dhanlaxmi and Prabhat as restorers and Pusa 1040 as maintainer for the CMS line IR58025A. Ingale et al. (2008) crossed 145 genotypes with 10 stable CMS lines and identified 40 effective restorers and 77 maintainers. Shiv Datt and Mani (2002) crossed Sixty Basmati rice cultivars with Basmati CMS lineir68281a. The cultivars IET 14709, VL Basmati 2 and Basmati Aman were identified as Basmati maintainers of cytoplasmic male sterility. Similarly Akhter et al. (2008) reported 16 maintainers in his study of which 8 are basmati and 8 are non basmati lines. Malarvizhi et al. (2003) crossed 291 cultivars with 6 CMS lines (WA). Based on pollen/spikelet fertility, they identified 30.4 per cent of the male parents as effective restorers and 13.7 per cent of the male parents as potential maintainers and the rest were grouped into partial restorers and partial maintainers. Sabar et al. (2007) evaluatd one hundred and nine genotypes for pollen fertility (%) and spikelet fertility (%) studies based on which he identified 20 restorers and 26 maintainers for use in hybrid rice development programme. Similar study was made by Bisne and Motiramani (2005). Udayashetty et al. (2001) studied pollen fertility (%) and spikelet fertility (%) in 161 rice hybrids and identified 23 maintainers viz., IET , IET , IET13863, IET and Vani2. Joshi et al. (2003) evaluated test crossed lines and they were grouped as restorer, partial restorer, maintainer and partial maintainer based on the pollen sterility and spikelet fertility. There was no strong evidence for a relationship between pollen fertility and spikelet fertility.

22 6 Durai and Nadarajan (2007) undertook a study with 50 cross combinations obtained by crossing five CMS lines of Wild Abortive (WA) source and ten male parents. They reported that six male parents viz., BR , IR , IR , MDU 3, MDU 4 and Ponni were identified as effective restorers for all the five male sterile lines. Akhter et al. (2008) identified 12 restorers and 16 maintainers (8 basmati and 8 non-basmati lines) from 239 test crosses, for use in hybrid rice breeding programme. They identified four basmati and eight coarse lines as restorers from the tested genotypes. Most of the genotypes were found as partial restorer and partial maintainer. Ingale et al. (2008) categorized the restorers as effective restorers (>80% spikelet fertility), partial restorers (20 to 79% spikelet fertility), partial maintainers (10-19% spikelet fertility) and maintainers (<10% spikelet fertility). Total 40 effective restorers and 77 maintainers were identified among 145 genotypes for ten CMS lines. Maximum maintainers were observed for PMS-5A line (72.5%) followed by COMS- 9A (60%), IR-62275A (43%), PMS-11A (26%) and IR-68892A (23%). The maximum effective restorers were observed for IR-68899A (55%) followed by IR-68275A (36%), IR 58025A (34%) and IR-68885A (33%). Sarial and Singh (2008) studied the identification of restorers and maintainers for developing basmati and non-basmati hybrids in rice, Oryza sativa L. The effective basmati restorers identified were Basmati 385, Chandan, P , HKR 241-IET , SAF Khalsa 7 and Karnal Local. The basmati maintainers identified were Basmati 370, Pusa Basmati 1, P615-K and P The frequency of restorers obtained was higher for the non-aromatic than the aromatic basmati type. Xie et al. (2008) identified a new high quality super hybrid rice combination, Taiyou 99, bred in China using the restorer line Luhuil 34S bred by selfing and high quality indica infertile line D62A. Based on the high yield, the quality of the infertile line was fully utilized in Sichuan for mediating the contradiction between high yield and high quality. Chen et al. (2009) studied that Mingfeng 1A is a new indica CMS line identified in China by crossing Jin 23A with elite plants of F3 generation of the cross

23 7 [(D297B x IR58025B) x Jin 23B]. Its main characteristics include complete and stable male sterility, good flowering habits with a high stigma exertion rate (78.73%), high combining ability, good restorability, fine grain quality. Wang et al. (2009) made the cross Jinnong 1A (A line) x Jinhui 3 (R line) to study the fertility inheritance of CMS-FA (A male sterile cytoplasm of Oryza rufipogon) hybrid rice. The results indicated that there was only one dominant gene controlling the fertility in the restorer line. Therefore, the genotypes of the three line of CMS-FA hybrid rice could be tentatively determined as for the male sterile line, F (SS) for the maintainer line and S (FF) for the restorer line. Gireesh et al. (2010) studied eighteen CMS lines and their isogenic maintainers for various morphofloral traits and revealed that the lies viz., KCMS10B, IR70369B, RTN10B, and IR68888B as good maintainer lines. The lines viz., CRMS 31B and IR68888B reported as good maintainers by Singh and Shirisha (2003). Jayasudha and Sharma (2010) identified RPHR and R as potential restorers for all the three CMS lines (CRMS 31A, CRMS 32A and IR 58025A). They concluded that the frequency of potential restorers is much higher in number and no effective maintainer could be identified in the material under study. Kumar et al. (2010) made efforts to identify maintainers and restorers out of 99 hybrids by using nine lines and eleven testers. Out of 99 hybrids MSN-20-13, MSN-62, MSN-63, MSN-64 and MSN-68 were identified as good maintainers while KMR-3, KMR-4, MSN-67 and MSN-69 as good restorers. Kumar et al. (2010) studied that out of twenty rice genotypes and of which eight pollen parents viz. IR B , IR B-R B, NDRK 5095, NDRK 5086, NDRK 5013, CSRC(S) , 22-2-B and 92-H 51-4 were found as partial restorers for both the CMS lines. Out of 20 pollen parent, only six viz. PNL , NDR , IR B-R B, IR R B, NDRK 5094 and Narendra Usar 3 were found as complete restorer to both the CMS lines. Sanghera et al. (2010) made efforts to develop new CMS lines in the background of agronomically adapted and popular varieties of the region using CMS

24 8 lines IR 68888A and IR 68897A. Test crosses were made under local conditions to identify effective restorers and maintainers involving both CMS lines. Umadevi et al. (2010) crossed eight CMS lines with 31 genotypes as testers to get 248 hybrids. The 248 hybrids were subjected to pollen and spikelet fertility analysis. Among the 248 hybrids 168 hybrids were found as restorers 52 as Partial Restorer, 28 as maintainers. Eleven testers viz., IR 62037, IR 72865, IR 68427, MDU5, TP1021, RR363-1, RR 347-1, RR 286-1, ACK and ASD06-08 were identified as restorers for all the eight CMS lines. Waghmode and Ingale (2011) made inheritance study using four effective fertility restorers and five diverse cytosterile sources and the study revealed the presence of fertility restoration gene(s) for five diverse cytoplasm in the genetical background of several elite lines studied. Four of the restorers were high yielding with several good traits. Khan et al. (2012) evaluated the identification of restorer and maintainer lines for tarai regions of Uttar Pradesh and Uttarakhand. Genotypes were categorized as Restorers (> 80% Spikelet fertility), Partial restorers (20 to 79% Spikelet fertility), Weak maintainers (10-20% Spikelet fertility) and Maintainers (< 10% Spikelet fertility). Out of 50 male lines, 19 lines behaved like restorer and 3 lines behaved like maintainer for both the CMS lines (IR 58025A and Pusa 6A) line. Srikrishna and Sharma (2012) with their study reported that based on the pollen fertility (%) and spikelet fertility (%) two genotypes i.e. Super rice-8 for APMS 6A and R for CRMS-32A were identified as potential restorers and two genotypes i.e. SR-6-SW-8-1 for APMS 6A and R for CRMS-32A were identified as maintainers. Sharma et al. (2012 a) found that among the genotypes tested, 16 were found to be common as effective restorers for all the three CMS lines. Three genotypes viz. Narendra Usar-3, CR and Maleshiya produced completely sterile hybrids with all the three CMS lines which may be used in developing new male sterile lines. Veeresha et al. (2013 b) crossed fifty three (53) rice genotypes with two CMS lines viz. IR 58025A and IR-68888A and resultant F1 populations were evaluated for

25 9 their restorability / maintainability. From these 53 test crosses, fifteen restorers and only one maintainer were identified for use in hybrid rice breeding programs. Most of the genotypes were found partial restorer and partial maintainer. Seesang et al. (2014) evaluated 31 test crosses which revealed 6 restorers and 9 maintainers based on pollen fertility. Singh et al. (2014) Studied three CMS lines IR 58025A (Wild abortive (WA) cytoplasm of Oryza perennis), CRMS31A (WA- cytoplasm) and CRMS-32A ( Kalinga cytoplasm from Dunghansali ) and 20 diverse testers. and these were crossed in line tester fashion to generate 60 hybrids. Out of 60 test crosses 9 restorers exhibited more than 80% pollen/spikelet fertility with heterotic morphological attributes. Out of 9 restorers two are aromatic short grain type and others 7 were coarse grain type. One maintainer was also identified. Frequency of partial restorer (37) and partial maintainer (11) were high. F1s viz. IR 58025A / IR and IR 58025A/ TOX showed high spikelet fertility. Ali et al. (2014) crossed three CMS lines with 43 genotypes to get 129 hybrids. Out of 43 F1s with IR 58025A, two were found complete sterile (IR 58025A/Kaliijira-9 and IR 58025A/ Sorukamini-2) and three as fully fertile (IR 58025A/Agali, IR 58025A/Benaful, and IR 58025A/Khasa). Kalijira-9 and Sorukamini-2 were identified as maintainer for IR-68885A which were common with IR 58025A. Aromatic line Benaful was identified as restorer for IR 58025A and IR62829A. Sahu et al. (2015) studied three CMS lines of rice having wild abortive (WA) and Kalinga cytoplasmic male sterility source. These were crossed with seven testers to identify their restorer/maintainer nature. Total of 21 hybrids were subjected to pollen and spikelet fertility analysis along with their parents. Most of the genotypes expressed differential fertility reactions when crossed with CMS lines source potential restorers were identified in this study among these, Bagdidhan was identified as restorer for all the three CMS lines. It was concluded that Potential restorers identified in the present investigation could be used to develop good, high yielding and promising rice hybrids. Hasan et al. (2015) crossed five CMS lines with 30 genotypes as testers to get 150 hybrids. The 150 hybrids were subjected to pollen and spikelet fertility analysis.

26 10 Among the 150 hybrids 25 hybrids were found as restorers 78 as Partial restorer, 22 as maintainers and 25 as partial maintainers. Four testers viz. BR7166-5B-1, F2277, PR828 and BR were identified as restorers for all the five CMS lines and three testers PR52, PR95 and PR185 were identified as complete maintainer for all the tested CMS lines. Mohana P. et al. (2016) reported that two cytoplasmic genic male sterile lines of rice viz., CO MS 24A and TNAU CMS 2A having wild abortive source were crossed with 20 testers to identify their restorer/maintainer nature. Total of 40 hybrids were subjected to pollen and spikelet fertility analysis along with their parents. Six effective restorers and eight maintainers were identified among the 20 genotypes. TKM 9 was found to be a common maintainer for CGMS lines TNAU CMS 2A and COMS 24A and the genotype ADT 37 was identified as restorer for both the CGMS lines COMS 24A and TNAU CMS 2A. The identified restorers and maintainers could be utilized for development of new rice hybrids and CMS lines in future. Upendi et al. (2017) studied that two cytoplasmic male sterile (CMS) lines of rice having wild abortive WA and one line with Kalinga cytoplasmic male sterility source were crossed with eleven testers to identify their restorer/maintainer under aerobic condition. Total of 33 hybrids were subjected to pollen and spikelet fertility analysis along with their parents. None of the genotypes were identified as potential maintainer based on pollen and spikelet fertility. Among testers only Kranti was identified as potential restorer for all the 3 CMS lines whereas, Danteshwari was identified as potential restorer for 2 CMS lines IR 58025A and IR 79156A. The other testers viz., MTU 1010, Abhaya, Indira Barani Dhan 1, IR , Chandrahasini, were identified as potential restorer for all three CMS lines. 2.2 Heterosis Heterosis is defined as the superior performance in the growth, vigor, vitality, reproductive capacity, stress resistance, adaptability, grain yield, grain quality and other physiological traits of F1 population of two genetically diverse parents (P) compared to either the mid- parent (MP) or better parent (BP) of the cross or to the check (CK) (Nanda and Virmani, 2000). Both positive and negative heterosis is useful in crop improvement, depending on the breeding objectives and nature of the trait.

27 11 Heterosis is a complex-biological phenomenon and several theories have been proposed to be the cause of heterosis. Review related to heterosis is presented as under: Tiwari and Sarathe (2000) found rice crosses viz., Kranti Mahamaya, JR 353 Mahamaya, Kranti Lallu and JR 353 RWR 54 very promising and identified them for further advancement. The highly significant heterosis and heterobeltiosis for plant height and 100 seed weight were observed. Zhang et al. (2000) studied Minghui-86 developed by crossing Indica-Japonica intermediate types with Indica type strong restorability material and crosses derived from Minghui-86 with other male sterile lines showed high heterotic value for grain yield. Jin et al. (2001) reported significant heterosis and heterobeltiosis for grain yield per panicle, but heterosis for 1000 grain weight and seed set rate were relatively in significant and heterosis for number of panicle per plant was negative. Liu and Shi (2001) reported positive heterobeltiosis for grain yield per plant and number of productive tillers per plant. Characters like 1000 grain weight, panicle length and seed set showed heterobeltiosis in hybrid rice developed by using WA-CMS lines. Nuruzzaman et al. (2002) studied eight quantitative traits in fourteen parental lines of hybrid rice for heterosis. They also showed that comparison of F1 hybrids with their respective mid parent and better parent had significant heterosis for most of the characters studied. Panwar et al. (2002) studied heterosis of 22 hybrids and among them the crosses PMS 1A/Pusa 44-33, PMS 2A/IR R, PMS 2A/Pusa showed significant positive heterosis for grain yield per plant, number of panicles per plant and grains per panicle. Verma et al. (2002) studied seven diverse rice ecotype along with their F1 and F 2 population for different characters. The majority of crosses showed significant heterobeltiosis and standard heterosis for yield and number of productive tiller per plant over standard variety 1 (Mahsuri) and standard variety 2 (Sarjoo 52).

28 12 Veni and Rani (2003) reported that IR 64/ Basmati 6129 showed maximum heterosis, heterobeltiosis and standard heterosis to the extent of 259.7, and 151 percent, respectively for grain yield. Vanaja and Babu (2004) suggest that yield increase was largely due to significant and favourable heterosis in yield components, i.e., number of spikelets per panicle, panicle length, leaf are per plant (at maximum tillering stage) and number of panicles per meter square. Similarly Rishika Sharma and Malik (2008) reported higher heterosis in yield accompanied by heterosis for one or more of the major yield components. Analysis of variance from twenty seven hybrids generated according to Line Tester mating design by Singh et al. (2005) revealed highly significant differences among the parents and parents v/s crosses. The mean sum of squares due to parents v/s crosses differed significantly for all the traits except for yield. In a similar study by Sao and Motiramani (2006) analysis of variance from fifty two hybrids generated according to Line Tester design exhibited the presence of non-additive gene action for all the characters studied. Soni et al. (2005) evaluated hybrids using 3 cytoplasmic male sterile (CMS) lines and 6 testers and indicated that heterosis for seed yield was due to the positive and significant heterosis for yield components, such as productive tillers per plant, panicle length and spikelet fertility percentage for the cross IR 68888A/IR 64. Faiz et al. (2006) attempted two CMS lines, IR69616A and IR70369A were crossed with (a fine grain aromatic advance line) and Basmati 385 (a commercial Basmati variety). The highest positive heterosis over better parents was observed for grain yield (41.83 %), number of productive tillers per plant (11.04 %) and number of filled grains per panicle (7.39 %) in the cross of IR69616A x Basmati 385. Pandya and Tripathi (2006) evaluated two wild abortive cytoplasmic male sterile lines (IR-58025A and IR-62829A) and fifteen restorers in Randomized Complete Block Design (RCBD). All the hybrids exhibited significant and positive heterobeltiosis for grain yield and related traits. They also found that heterosis for yield

29 13 per plant was due to positive and significant heterosis for number of tillers, panicle length and yields per plant. Chaudhry et al. (2007) indicated moderate to high heterosis for grain yield, days to 50% flowering, plant height, leaf area index (LAI) and grain yield per plant. Munisonnappa and Vidyachandra (2007) conducted experiment using seven newly developed rice hybrids and two check varieties was laid out in a RCBD. They found positive and significant standard heterosis for spikelets per panicle in hybrids DRRH-1, PHB-71 followed by hybrids KRH-2, PA 6201, KMRH-4 and Sahyadri. They found that APRH-2 recorded negative significant heterosis over both the checks. They identified that hybrid DRRH-1 proved to be superior as it had significant positive heterosis for grain yield in most of the environment followed by Sahyadri and KRH-2. Raj et al. (2007) evaluated eighteen parents and forty-five crosses for relative heterosis, heterobeltiosis and standard heterosis for yield. They found hybrids viz., BR- 9 x Cauvery, BR-10 x IR-8, janki x Archana, Birsa Dhan-202 x Cauvery and IR-36 x IR-8 were best for heterosis pertaining to grain yield per plant. Jayasudha (2008) studied thirty three hybrids generated from crossing three lines with eleven testers along with their parents and identified IR 58025A/OR RAU , CRMS 31A/IR NDR-1-1, IR 58025A/R , CRMS 32A/R and CRMS 31A/RPHR as good heterotic crosses. Ratnakar et al. (2009) estimated heterosis in CMS based hybrids of rice with respect to grain yield and its components using 30 hybrids. Result indicated that the hybrid PMS 8A x NDRK 5028 recorded maximum grain yield with and per cent heterosis over the better parent and standard cultivar, respectively. Similarly Tiwary et al. (2011) reported significant heterosis of 11.63% to per cent in 43 hybrids and standard heterosis of to per cent in 46 hybrids over standard variety (Sarjoo-52). Ramakrishnan et al. (2009) generated ten F1 hybrids of rice (Oryza sativa L.) using 14 parents and studied the extent of heterosis. The best performing F1 hybrid ASD 18 x ADT 36 showed maximum heterosis and heterobeltiosis for yield. The

30 14 hybrids ASD 16 x ADT 30, ASD 18 x ADT 36 and ADT 39 x ASD 18 showed more than 20% of heterobeltiosis for grain yield. Wang et al. (2010) studied to detect the genetic effects and heterosis level of yield related traits of CMS-FA sterile lines and restorers as well as the breeding potential of CMS-FA hybrid rice parents. Three yield-related traits yield per plant, plant height and panicle length had stronger population mean heterosis. Mirarab et al. (2011) conducted the study on heterosis in rice by using Five lines and two testers in line tester manner to produce ten F₁ hybrids. In this study heterosis was observed for tiller number and grain yield in combinations of IR 42 IR and IR 42 Usen. Kumar et al. (2012) studied 28 F1 S excluding reciprocals were developed using 8x8 diallel. Mid parent, better parent and standard heterosis were estimated for yield and its components. Crosses Pant Sugandh Dhan 15 x UPR , Pant Sugandh Dhan 15 x UPR and Pant Sugandh Dhan 17 x UPR had shown high standard heterosis for grain yield, biological yield and for harvest index. Kumar et al. (2012) the heterosis study on grain yield and its components from line x tester analysis from 12 F1 s hybrids derived from 3 female and 4 male lines. The highest heterotic effects observed for better parent and mid parents were 6.04% and 21.15% for grain yield per plant noted for the crosses Sarjoo 52 NDRK 5088 and IR 64 CSR 13, respectively. Maximum heterobeltiosis for biological yield per plant, test weight and days to maturity and maximum heterosis over mid parent for biological yield per plant, test weight and days to maturity was found in Sarjoo 52 x CSR 13. The crosses mentioned above could be utilized in obtaining high yielding with early maturity hybrids. Patil et al. (2012) carried out LxT analysis using a set of four lines and ten testers to estimate the heterobeltiosis for yield and its components in rice. Sufficiently high magnitude of heterobeltiosis in desirable direction was observed for grain yield per plant, grains per panicle, panicle per plant, panicle length, days to 50% flowering, 1000 grain wt. and L/B raio. As many as sixteen crosses showed significant positive

31 15 heterosis over their respective better parental value for grain yield per plant. Crosses Sathi x Lalkada, Sathi x GR-6 and GR-5 x GR-6 were found to be most heterotic hybrids for grain yield per plant. Sharma et al. (2013) evaluated the magnitude of heterobeltiosis for grain yield significantly in 28 hybrids ranging from to 66.35% and only in 2 hybrids (IR58025A Sarju-52; IR58025A BPT5204) over the standard hybrid (Arize-6444) with the magnitude of and 20.60% respectively. These crosses also exhibited significant heterosis for days to maturity, number of spikelets per panicle, number of grains per panicle. The most promising combinations (IR58025A Sarju-52 and IR58025A BPT5204) for grain yield and other traits need to be tested on larger scale for their commercial values. Besides these, few other crosses viz; Pusa6A BPT5204,IR68897A BPT 5204 and Pusa6A Krishna Hansa expressed more than 40% heterobeltiosis for grain yield alongwith other desirable yield components may be considered for commercial exploitation. Gnanamalar and Vivekanandan (2013) were estimated relative heterosis, heterobeltiosis and standard heterosis for yield and quality characters. High amount of heterosis existed for grain yield, hundred grain weight, hulling percentage, milling percentage, head rice recovery, linear elongation ratio, water uptake, volume expansion ratio and amylose content whereas it was low for the quality traits viz., kernel length, kernel breadth, kernel L/B ratio, kernel length after cooking and alkali spreading value. The hybrids viz., ACM / AS 90033, ADT 41 / ADT 46, ADT 41 /ACM 98003, ADT 41 / AS 90033, CO 47/ TKM 9 and CO 47 / ACM performed well for grain yield combined with several grain quality traits viz., hulling percentage, milling percentage, linear elongation ratio, water uptake, volume expansion ratio and amylose content, so these promising cross combinations can be further used in rice breeding programme. Rajkumar and Ibrahim (2013) the investigation was carried out under aerobic condition using the line x testers mating design and studied for yield and its components traits. The objective of this study was carried out to identify the best combining parents and their hybrids suitable for aerobic cultivation. One hundred and thirty six hybrids along with eight lines, seventeen testers and one check CORH 3 were

32 16 raised in randomized block design with two replications under aerobic condition. Nineteen hybrids showed desirable performance for all the yield traits. However, most of the hybrids involving aerobic and upland genotype as male parent exhibited hybrid vigor for yield and its component traits. Parental lines of the hybrids also had high per se performance for grain yield. Out of nineteen hybrids, five hybrids viz., IR A x MAS 946-1, IR A x BI 33, IR A x IR R, IR A x MAS 26, TNAU CMS 2A x Vandana advocated for commercial exploitation since grain yield with its contributing characters manifested significantly for standard heterosis. Among this hybrid standard heterosis ranged from percent in grain yield to percent in flowering duration and showed marked variation in the expression of standard heterosis for yield component traits. Finally these hybrids as well as parents can be commercially exploited under aerobic condition. Ghara et al. (2014) carried out carried out an experiment according to line x tester mating design to identify best heterotic hybrids. They observed that the cross Amol A IR was best heterotic hybrids followed by other eight crosses for yield and most of its related traits. Shinde and Patel (2014) studied the magnitude of heterosis among forty cross combinations developed through line x tester mating design from four lines and ten aerobic rice testers. It was observed that most of the characters exhibited high heterotic response and existence of substantial amount of genetic variability among parents and hybrids. It is clear that yield attributing characters plays major role in yield maximization. Simultaneously, best performing genotypes such as NVSR-178 and NAUR-1 could be the potential source of breeding material for improvement in aerobic rice. Nayak et al. (2015) estimated heterosis, heterobeltiosis and standard heterosis for grain yield and quality traits in sixteen cross combinations to develop heterotic hybrids. Among the heterotic crosses RNR 2354/BM-71(Number of panicles per plant, Panicle length), Ranbir Basmati/MTU-1010 (250 Grain weight, Protein), RNR2354/Sye (Number of filled grains per panicle), Pusa 1121/MTU1010 (Grain yield), Yamini/MTU1081 (Water uptake) and Yamini/Sye (Alkali

33 17 spreading value) were found to be superior, expressing heterosis, heterobeltiosis and standard heterosis in desirable direction. Huang et al. (2015) observed heterosis for plant height, grain number per panicle, and other yield related traits of hybrid rice Liangyoupeijiu (LYP9) and its parents (Pei ai 64S and 93-11) under natural- and short-day length condition. Bedi et al. (2016) reported that To increase production and productivity in this ecosystem, innovative breeding approaches such as heterosis in hybrid rice. Out of these, hybrid rice technology is the proven technology in China and a more practical one to raise production. Hetrosis study comprises of three CMS lines viz., CRMS 31A, IR 58025A and IR79156A and five testers viz., NPT 453-2, NDR 8054 (IR NDR-B ), CR , NPT 76-8 and PR-115. Indira Sona (hybrid) and Mahamaya (commercial cultivar).the crosses were tested as line x tester mating design with two replications. Cross IR 79156A / NPT 76-8 stood for positive significant heterosis over checks for characters grain yield / plant,test weight, pollen fertility percentage, harvest index. 2.3 Combining ability Combining ability analysis helps in the identification of parents with high general combining ability (GCA) effects and cross combinations with high specific combining ability (SCA) effects. Additive and non-additive gene action in the parents estimated through combining ability analysis may be useful in determining the possibility for commercial exploitation of heterosis. The average performance of a parents or inbred in a series of cross combinations is known as its general combining ability and the performance of two specific inbred in a particular cross combination is known as its specific combining ability. The literature on the combining ability in rice is reviewed here under the following sub-heads: General combining ability (GCA) and Specific combining ability (SCA) Sprague and Tatum (1942) made a distinction between general combining ability (GCA) and specific combining ability (SCA) as the average performance of a line in a series of cross combination and further assumed that GCA was dependent on

34 18 the additive effects of genes. The SCA was used for those cases in which certain cross combinations do relatively better or worse than would be expected on the basis of average performance of lines involved. The SCA depends on genes with dominance and epiestatic effects. The literature on the combining ability in rice is reviewed here: Babu et al. (2000) evaluated 32 crosses with L x T fashion and found CMS lines IR 58025A, IR 62829A and testers WGL 3962, IET 9762 and IET as good general combiners for yield and other yield attributes. Hasib et al. (2001) reported that mutant of Tulaipanja ( and ) were good general combiners for panicle length, grain length and L: B ratio; Gobindabhog mutant was a superior general combiner for panicle weight, spikelet per panicle and grain yield per panicle. Reddy (2002) recorded that CN was found to be good combiner for panicle weight, number of filled grains per panicle and plant height. They reported that Utkalprabha/CN , OR /CN , OR /CN and CN /CN showed significant positive sca effects for grain yield per plant. Bhave et al. (2003) studied combining ability analysis for yield and yield components using 32 F1 hybrids, 16 restorer lines and 2 maintainer lines of rice. IR 62829A, RTN 68 and KJT 14-7 appeared to be good general combiners for days to 50 per cent flowering and maturity. IR 58025A, RTN 68 and KJT-4-7 were good general combiners for grain yield per plant. IR 58025A/RTN 68, IR 58025A PNL 1 and IR 62829A PNL 2 which showed high specific combining ability effects were best combination for hybrid breeding. Manomoni and Khan (2003) observed that CO 43 showed high gca for tiller number and higher grain yield. ADT 40 exhibited high and positive gca effect for grain yield, number of filled grains per panicle, panicle length and negative gca effect for plant height. Vanaja et al. (2003) reported that Vyttila 3 were found to be a good general combiner for grain yield and important yield components like number of days to 50 per cent flowering, harvest index, length of panicle and amylose content.

35 19 Kumar et al. (2004) found that PSRM and RAU were best combiner for yield and its most of the related characters and reported that the crosses, IR 68886A Pusa 1040, IR 68886A PSRM , IR 58025A Gautam, IR 68886A RAU and IR 68897A Dhanalaxmi exhibited high and significant sca effects for grain yield. Bagheri et al. (2005) evaluated 6 lines and 3 testers and their 18 F1 hybrids. Theyfound that hybrid 8 exhibited superior specific combining ability (SCA) for yield, while hybrids 12 and 15 showed significant SCA for number of filled grains and panicle length respectively. Panwar (2005) studied combining ability analysis in line x tester design using three lines, ten testers and their 30 hybrids and found that the IET-13846, Kasturi, Basmati 370, Pusa Basmati-1, Tarori Basmati and IR-64 were good general combiners for grain yield per plant. He also found that cross combination viz., IET x Pusa Basmati-1, IET x IR64, IET x Kasturi and IET x Tarori Basmati has high per se performance with significant SCA effects for grain yield. Sharma et al. (2005) used 10 testers and 3 lines to their 30 F1 cross combinations using line x tester mating design. They revealed the lines Punshi, KD and testers Neela and Satary were proved as good combiners for grain yield per plant. They identified Neela as good combiner for days to 50% flowering. Kumar et al. (2006) carried out combining ability analysis for grain yield per plant, days to 50% flowering, plant height, productive tillers per plant, panicle length, number of fertile grains per panicle and spikelet fertility percentage involving CMS line and nine pollen parents. They found that the CMS line like IR 68886A was superior general combiner for earliness and IR 58025A was superior general combiner for yield and its components. Some parents were found as good general combiners for yield. Murugan and Ganesan (2006) evaluated a few crosses and their parentages and found that L3 and testers T1, T2, and T6 as good general combiners for most of the traits including grain yield per plant. They also found hybrid L2 x L3 as good specific combiners for grain yield.

36 20 Sao and Motiramani (2006) studied combining ability on rice using line x tester design and found that DRR 22A was a good general combiner for plant height; IR 62829A was a good general combiner for number of spikelet per panicle and grain yield per plant; IR 67684A was also good general combiner for number of productive tiller per plant, number of filled spikelet per panicle, spikelet fertility percentage and pollen sterility percentage, whereas IR 68899A was rated as good general combiner for number of chaffy spikelet per panicle. Tester Swarna was found best general combiner for grain yield per plant. Alam et al. (2007) found comprising 5 line x 5 tester mating design was conducted to study the nature and magnitude of gene action i.e. general combining ability (GCA) and specific combining ability (SCA) of yield and 8 yield contributing characters in rice. Among the CMS lines, IR75595A and IR62829A were found to be good general combiners for most of the characters. Among the testers, BAU509R and BAU525R were observed to be good general combiners for most of the characters studied. A number of cross combinations were observed to be good specific combiner for grain yield and yield related traits. Singh et al. (2007) carried out combining ability analysis for grain yield and its components in seven parents and found significant GCA and SCA effects for all the seven characters. The per se performance was also to be a good indication of GCA effects of the parents and SCA effects of the crosses. They concluded that the parents Vaidehi and Rajshree were good general combiners for grain yield. Kumar (2008) reported the preponderance of non-additive gene action for all the characters under study. Among lines VL 16 and BR 240; and among testers IR64, LTH and IRBL 10 were good general combiners for yield and its related characters. Hybrids F7 10/MTU 1010, BR 240/MTU 1010, B6441-F-MR-6-0-0/LTH were best specific combiner for grain yield and its related characters. Shivani et al., (2008) reported the cross Norin Pl9 X IR29723 with highest sca effect for good head rice recovery. For kernel dimensions like kernel length, L/B ratio and KLAC, the cross Norin PL9 X IR showed highest positive sca effect. Japonica/indica cross combination involving Norin PL9 with IR 29723, IR and IR 13419, IR with KMR 3, NDR 3026 and IR and IR

37 21 with KMR 3, NDR 3026 and IR showed positive sca effects indicating there utility to get hybrids with soft gel consistency. Shukla and Pandey (2008) analysed combining ability and heterosis over optimum and high fertility environments for six traits using 120 hybrids Pooled analysis revealed highly significant variance for lines, general combining ability, specific combining ability and line x tester. TGMS line was the best general combiner for all the six traits including grain yield. Zhu et al. (2009) studied ten male sterility lines and ten restorer lines for combining ability of yield and related traits classified by six different types of cytoplasm. The results showed that the number of panicle, plant height, panicle length, grain number per panicle,filled grain per panicle of different types of cytoplasmic combinations was mainly affected by the additive effects. The weight of 1000 grains and yield per plant were affected by the additive effects and non-additive effects together and the additive effects were greater than non-additive effects. The seed setting rate was mainly affected by the non-additive effects. The plant height, panicle length, grain number of panicle, filled grain of per panicle, seed setting rate and weight of 1000 grains were affected by the general combining ability (GCA) of different type of cytoplasms in male sterility lines. The number of panicles andyield of one single plant were affected by the GCA of restorer lines. Bagheri and Jelodar (2010) studied combining ability analysis for yield and related yield traits in hybrid rice and found higher SCA variances than the GCA variances for most of the traits. They also observed CMS line IR 62829A and IR 50 to be good general combiners and four cross to be good specific cross combinations for grain yield and most of the characters studied. Soni (2011) reported that only one line IR79156A was found to be the good general combiner and among testers ET1-13, IRFAN-115, and ET1-12, were found to be superior general combiners for yield and attributing characters. The promising hybrids in presentstudy offer greater scope for further exploitation of hybrid vigour commercially.

38 22 Mirarab et al. (2011) conducted the study on heterosis, combining ability and genetic parameters of yield and yield components in rice by using five lines and two testers in line tester manner to produce ten F₁ hybrids. Results showed that general combining ability (GCA) effect was only significant for total number of kernels per panicle, number of filled kernels and grain yield per plant, and specific combining ability (SCA) effect was significant for yield and all of its studied components (except for 100-kernel weight). Ghara et al. (2012) study of general and specific combining ability conducted on 50 F1 hybrids along with 15 rice genotypes (5 cytoplasmic male sterile lines and 10 restorer varieties) to know the pattern of inheritance of some morphological traits for selecting superior genotypes. Analysis of variance indicated significant differences among genotypes, crosses, lines, testers and line tester interactions for tiller number, plant height, days to 50% flowering, panicle length, number of spikelets per panicle, spikelet fertility and grain yield traits. Variances of SCA were higher than the GCA variances for traits which indicated predominance of non-additive gene action in the inheritance of the traits. The proportional contribution of Line tester was observed to be higher than that of the interactions of line and tester except for number of spikelet per panicle. Gautam et al. (2012) identified the two CMS lines, PMS11A and PMS12A and six restorer s viz., IR 32841, PAU , PAU , PAU , PAU2024 and IR as good general combiners for exploiting heterosis. Gopikannan and Ganesh (2013) found higher specific combining ability (SCA) variances than the corresponding general combining ability (GCA) variances for all the traits under study which indicated preponderance of non-additive gene action governing those traits. Results of per se and GCA effects of parents revealed that multiple crosses involving IR 20, CO (R) 50, FL 478, TRY (R) 2 and CSR 23 would be considered as invaluable sources of genetic materials. Bhadru et al. (2013) reported that IR-79156A, IR-68897A and tester R-51 during both the seasons and testers R-47, R-48, R-49, R-52, IR-64 and IR during Kharif and testers R-42, IR-66, R-43, R-46, R-56 and IR during Rabi were the promising general combiners for grain yield per plant and other traits.

39 23 Hasan et al. (2013) found that the tester D. Shan-A is the only good general combiner among the female parents for earliness and dwarfness. Male parent IR 64R was best general combiner for dwarfness. The crosses BRRI9A BR168R and D. Shan A BR168R were identified as most promising for yield and desired traits based on sca effects, per se performance and GCA effects of parents for grain yield and its components. Ghosh et al. (2013 b) in their study found that the lines, CRMS-31A and IR A were good combiners for head rice recovery percent. The tester NPT 80-1 was good general combiner for grain yield per plant and TOX for both grain yields per plant and head rice recovery percent. The cross combinations APMS 6 A/ET 1-13, CRMS 31 A/ET 1-12, and IR A/ NPT 80-1 were found to be outstanding with respect to grain yield per plant, head rice recovery percent and spikelets per panicle. The cross APMS 6 A/NPT was good combiner for head rice recovery percent. Soni and Netam (2013) identified that among the lines IR-79156A was a good general combiner followed by APMS 6A and IR 58025A and among the testers ET 1-13, IRFAN-115, and ET 1-12 were found to be good combiners for grain yield per plant. Promising hybrids based on per se performance, SCA effects GCA effects and Heterosis for grain yield per plant were IR-79156A/ET-1-10, APMS6A/ET1-12, IR A/IRFAN-115, IR-79156A/ET-1-1and IR-79156A/TOX Malik and Singh (2013) found that PUSA 6A in testers and UPR in lines are good combiners for grain yield and other yield related component traits based on their GCA effects. Top hybrids expressing highest SCA obtained with good general combiners were UPRI x UPR , UPRI 95-17A x UPRI and x UPRI 95-17A x UPR Two testers viz., UPR and UPR were identified as good general combiners based on their mean performance and GCA effects for yield and its various traits. Shiva Prasad et al. (2013) in their study identified the parents, IR-64, Ujala Depama and Malida as good general combiners. IR64 X Ujala Depama, IR64 X Malida and MTU-1010 X Ujala Depama were good specific combinations.

40 24 Utharasu and Anandakumar (2013) found the parents PMK3, RMD(R)1, ARB6, ARB7, ARB8 and CB as the good combiners for drought tolerant and yield traits. The crosses RMD(R) 1/ARB7, PMK3/ARB8, PMK3/ARB7, ADT43/IR B-34-3 and MDU5/Anjali were identified as best specific combinations for grain yield. Pratap et al. (2013) found that, among the lines IR 58025A and IR 79156A; among testers Narendra Usar 3, Swarna, Usar 1, Pankaj, Pusa Sugandha 3 and Taraori Basmati were identified as good general combiners for yield and other related components. Among these Narendra Usar 3 showed good GCA for majority of the yield enhancing traits except L: B ratio (-0.08) and spikelets per panicle (-4.81). Sathya and Jebaraj (2013) Studied combining ability and heterosis in 21 parents and 90 hybrids for yield and physiological traits under aerobic condition. Analysis of variance was highly significant for all the characters and predominantly controlled by non additive gene action. The hybrids IR-70369A / IR 7925A R, IR 79156A / BR -2655, IR-70369A /KMP-105 and IR 79156A /KMP -149 were found to be good specific combiners for most of the yield contributing and drought tolerant traits including single plant yield. Rajkumar and Ibrahim (2013) Carried out their investigation under aerobic condition using the line x testers mating design. The objective of this study was to identify the best combining parents and their hybrids suitable for aerobic cultivation. Among these hybrids standard heterosis ranged from percent in grain yield to percent in flowering duration and showed marked variation in the expression of standard heterosis for yield component traits. They concluded that some of these hybrids as well as parents can be commercially exploited under aerobic condition. Raju et al. (2014) studied combining ability for single plant yield and its components through L x T analysis involving 5 lines and 13 testers. Among the lines APMS 6 A and the testers JGL 8292, JGL 8605, JGL 17211, JGL and JGL 3844 were found to be good combiners for grain yield, by exhibiting the high gca effects. Adilakshmi and Upendra (2014) studied Combining ability with seven parents and twenty one F1s for quality and nutritional traits. Among parents Indira found to be good general combiners for hulling, milling, head rice recovery, L/B ratio and grain

41 25 yield per plant. Results indicated that the sca variance was greater than GCA variance for all the characters. Hasan et al. (2015) studied combining ability for 9 quantitative characters through line x tester analysis involving 5 lines and 4 testers. The combining ability analysis revealed non additive gene action governing all the 9 characters. Among the parents, BRRI7A, IR-75608A, Basmati R, BRRI26 R and BRRI31 R found to be good general combiners for grain yield. Sathya and Jebaraj (2015) carried out six lines and 15 testers crossed in a Line x Tester mating design and the 90 hybrids along with 21 parents were tested for gene action, combining ability for 19 traits under aerobic condition. Three lines viz., IR79128A (L1), IR79156A (L2) and IR70369A (L4) and three testers viz., IR7925A R (T11), KMP -148 (T12) and BI- 33 (T15) were identified as the best general combiners. Genotype IR70369A is suggested for conversion to cytoplasmic male sterility with suitable male sterile source. Parents MAS -26, IR 7925A R and KMP-105 are recommended for testing their restorability with suitable cytoplasmic male sterile source. Bedi S. and Sharma D. (2016) reported that to increase production and productivity in this ecosystem, innovative breeding approaches such as heterosis in hybrid rice.out of these, hybrid rice technology is the proven technology in China and a more practical one to raise production. Hetrosis study comprises of three CMS lines viz., CRMS 31A, IR 58025A and IR79156A and five testers viz., NPT 453-2, NDR 8054 (IR NDR-B ), CR , NPT 76-8 and PR-115. Indira Sona (hybrid) and Mahamaya (commercial cultivar). The crosses were tested as line x tester mating design with two replications. Cross IR 79156A / NPT 76-8 stood for positive significant heterosis over checks for characters grain yield / plant,test weight, pollen fertility percentage, harvest index. Sahu et al. (2016) Study of combining ability and genetic behavior of the parents are essential to search newer hybrid combinations with better grain quality features. An experiment was conducted on twenty one crosses which were generated in line x tester (LxT) fashion by using three CMS lines a nd seven testers. The LxT interaction was significant for all 23 traits taken under study. The magnitude of specific combining

42 26 ability variances was higher than that of general combining ability variance for all the traits under study indicating a key role of non-additive gene action in controlling these traits. IR79156A was identified as a good general combiner for grain yield per plant because it exhibited the positive GCA effect with many desirable traits, whereas CRMS32A was identified as best general combiner for most of the quality traits viz., head rice recovery, hulling%, milling%, and elongation ratio. Among the testers, Karmamahsuri, Suraksha, Bagdidhan and TOX were found to be a good combiner for grain yield per plant and other related traits. TOX , Karmamahsuri and Bagdidhan were identified as a good general combiner for head rice recovery and other quality traits. Crosses IR58025AxSuraksha, IR58025AxInger-2114, CRMS32AxKarmamahsuri, IR79156AxKarmamahsuri and IR79156AxRIL-62 showed the higher SCA value for grain yield per plant. IR58025AxSuraksha, IR58025AxTOX , CRMS32AxInger and IR58025AxKanakgopala were identified as promising hybrid based on SCA effect for head rice recovery and other quality traits.

43 3.1 Experimental site CHAPTER - III MATERIAL AND METHODS The present study entitled Identification of suitable rice hybrids adaptable to aerobic condition was conducted at Research Farm, Department of Genetics and Plant Breeding, Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.) in Kharif 2015 and Kharif Raipur is located at N Latitude and E longitude at an altitude of meters above the mean sea level. 3.2 Meteorological data The meteorological data indicates that the total rainfall received during crop growth period was mm (18 June to 18 November 2016). Highest amount of rainfall during crop growth period was received in third week of July ( mm). The meteorological data depict a favourable season for crop growth but due to continuous and unevenly spread of rains in this region, adversely affected the growth of crop (Table 3.1). 3.3 Experimental material The biological materials used in the present study comprises of three lines viz., IR58025A, IR79156A and CRMS 31A and eight tester viz., R , R , R , R , R , AP-16, AP-18 and Reg Total twenty four crosses were attempted by adopting L x T design (Kempthorne, 1957). Two check viz., Indira barani dhan and Indira sona were also included to evaluate standard heterosis. Hybrid check JRH -5 grown in kharif 2016 but due to bacterial leaf blight attack yield not obtained so Indira Sona used as hybrid check. Details of these parents used are presented in the (Table 3.2). 27

44 28 Table: 3.1 Weekly meteorological data recorded during the crop season (18 June to 18 November 2016) Wk No. Date Max. Temp. Min. Temp. Evaporation Shine Sun Rainfall Rainy Relative Humidity Vapour Pressure Wind (%) (mm of Hg) (mm) Days Velocity (mm) (hours) I II I II (Kmph) 25 Jun Jul Aug Sep Oct Nov Total/Mean

45 Source: Department of Agricultural Meteorology, IGKV, Raipur (C.G.) Fig: 3.1 Weekly meteorological data recorded during the crop season (18 June to 18 November 2016) 29

46 IR 58025A IR 79156A CRMS 31A 30 Crossing Process

47 31 Table 3.2: Details of parents used in the study Genotypes Parentage Source Female Parents IR 58025A (WA) IR 48483A/Pusa IRRI, Manila,Philippines IR 79156A (WA) IR68897A/IR IRRI, Manila, Philippines CRMS 31A (Kalinga) Kalinga 1 CRRI, Cuttack Male Parents R R /Phalguna IGKV,Raipur (C.G.) R Danteshwari/Amrit bhog IGKV,Raipur (C.G.) R Danteshwari/WGL IGKV,Raipur (C.G.) R CN /Vasumati IGKV,Raipur (C.G.) R Samleshwari/TRC IGKV,Raipur (C.G.) AP-16 Ajam Dhan Landrace AP-18 Ramgali Landrace REG-1649 Dadbako Landrace Checks INDIRA BARANI DHAN Swarna/IR IGKV,Raipur (C.G.) INDIRA SONA IR58025A/R IGKV,Raipur (C.G.) 3.4 Methods Nursery Sowing For the development of F₁ hybrids, three male sterile lines used as female and eight male parents (Table 3.2) were sown in nursery in different dates to ensure synchronization for the purpose of hybridization. The 21 day old seedlings of parents were transplanted in crossing block each in keeping cm spacing and three CMS lines were transplanted in separate block to avoid out crossing with other parents Hybridization Eight male parents were crossed to each of the three CMS lines to generate a set of hybrids in a line x tester fashion as proposed by Kempthorne (1957). In order to increase the seed settings, the spikelets of CMS plant that were expected to flower the next day were clipped one third at the top.

48 32 The clipped panicles were completely covered with butter paper bags to avoid outside pollen grains to fertilize the CMS plants. In the next morning (about 8:30 am) panicles from the male parents were collected at anthesis time and were kept in pollination room at temperature of 40 0 C under high humidity in glass bottles. After complete anthesis the pollen grains were dusted over clipped spikelets with proper precaution. The pollinated panicles were immediately bagged again and labeled properly with date and cross combination. In this way, 24 crosses were attempted for the present study. The bagged panicles were harvested and separated from mother plants after thirty days of hybridization. The hybrid seeds of each cross were collected separately and were sun dried. The seeds were also treated with bavistin as a precautionary measure against fungal attack before storing in paper bags Raising F 1 s and parents During Kharif 2016, the treated seeds of total 24 hybrids generated during the previous season were carefully germinated in seed germinator. 11 parents (instead of A line using as parents B line) and two check variety were also sown in nursery beds in the same day Planting of F 1 s and parents in Kharif 2016 About 21 days old seedlings of total 24 hybrids and their 11 parents (instead of Aline using as parents B line) and two check variety were planted in Completely randomized block design (CRBD) with three replications during kharif 2016 for Aerobic condition. Material were evaluated in aerobic condition by direct seeded sowing with row spacing of 20 cm. Recommended package of practices was followed Observations recorded In each treatment, observations were recorded on five randomly selected plants in both the replications for following traits. The mean value over five plants was considered for further statistical analysis.

49 33 Table 3.3 List of characteristics, taken under investigation Agro-morphological Characteristics Quality Characteristics 1. Days to 50 % flowering 1. Hulling % 2. Plant height (cm) 2. Milling % 3. Productive tillers per plant 3. Head rice recovery ( % ) 4. Panicle length (cm) 4. Paddy length (mm) 5. Total number of spikelet per panicle 5. Paddy breadth (mm) 6. Number of sterile spikelet per panicle 6. Paddy L/B ratio 7. Number of fertile spikelet per panicle 7. Brown rice length (mm) 8. Spikelet fertility percentage (%) 8. Brown rice breadth (mm) 9. Pollen fertility percentage (%) 9. Brown rice L/B ratio 10. Test weight (g) 10. Kernel length(mm) 11. Grain yield (g) per plant 11. Kernel breadth(mm) 12. Biological Yield (g) per plant 12. Kernel L/B ratio 13. Harvest index (%). 13. Kernel length after cooking (mm) 14. Seedling vigour 14.Kernel breadth after cooking (mm) 15. Flag leaf width (cm) 15.Cooked rice L/B ratio 16. Leaf colour 16.Elongation ratio 17. Chlorophyll content 17.Alkali spreading value 18. Relative water content Agro-morphological Characteristics 1. Days to 50 % flowering The number of days from sowing to the date when primary panicles in 50 per cent plant were in heading. 2. Plant height (cm) The height of plant was measured in centimeters from the ground level to the tip of primary panicles at the time of harvest.

50 34 3.Productive tillers per plant The total number of panicle bearing tillers in each plant was recorded at the time of harvest. 4. Panicle length (cm) The length of five panicles of each plant was measured from the base to the tip of the panicle excluding awn if any at the time of harvest. 5. Total no. of spikelets per panicle The total number of spikelets were counted per panicle. 6. Sterile spikelets per panicle The number of unfilled spikelets per panicle was recorded. 7. Fertile spikelets per panicle The number of filled spikelets per panicle was recorded. 8. Spikelet fertility percentage (%) The panicle was threshed and sterile and fertile spikelets were counted. Spikelets fertility percentage was calculated as follows: Spikelet fertility percentage (%) = Number of fertile spikelets Total Number of spikelets Pollen fertility percentage (%) This observation was recorded using a microscope to count pollen grains. The florets were first preserved in 1:3 acetic acid and alcohol. Later on the pollen fertility counts were taken by using 1% iodine potassium iodide (I2-KI) solution as stain (Annexure-II). The stained pollen grains were counted as fertile. The total counts of fertile pollen grains were seen in relation to the total pollen grains in five microscopic fields. Mean values for fertile pollen (stained pollen) and total pollens were used for calculating the pollen fertility percentage. Pollen fertility percentage (%) = No. of stained pollen grains Total no. of pollen grains 100

51 Test weight (g) Thousand seed of each entry were taken randomly and weighted in gram. 11. Grain yield per plant (g) The weight of seeds (filled) of each plant in grams was recorded. 12. Biological yield per plant (g) Weight of each plant excluding root was recorded and expressed in grams. 13. Harvest Index (%) The ratio of grain yield to the biological yield of each plant was calculated and expressed as percentage: HI (%) = 14. Seedling vigour Economic yield (grain yield ) Biological yield (bundle weight ) X 100 The sum total of those properties of the seed which determine the level of activity and performance of the seed or seed lot during germination and seedling emergence, it was recommended that the term should be used to describe the performance of seed when sown in field. 15. Flag leaf width (cm) The leaf blade width of the flag leaf was recorded as flag leaf width. 16. Leaf colour The leaf colour chart (LCC) is used to determine the N fertilizer needs of rice crops. LCC has four green strips, with colour ranging from yellow green to dark green. It determines the greenness of the rice leaf, which indicates its N content. 17. Chlorophyll Content Chlorophyll content (SPAD Value) in young succulent leaves of each plant was recorded through Chlorophyll meter (Spadometer) at 25 days old seedlings. 18. Relative water content (%) RWC, in young succulent flag leaf of each plant was recorded. RWC % = Fresh wt - Dry wt Turgid wt Dry wt X 100

52 36 Quality characters 1. Hulling (%) 50 g of paddy sample was used; it was properly cleaned, before starting the dehulling. the dehusking of rice was done by dehusker and hulled rice weight was recorded. Hulling percentage = Weight of the dehusked kernel Weight of paddy X Milling (%) Brown rice was put into standard miller or polisher and later milled rice weight was recorded. Milling percentage = Weight of polished kernel Weight of paddy X Head rice recovery (%) From milled rice the ¾ kernel was taken as whole grain. The sorting out of full and broken rice was done and its weight was recorded. HRR (%) = Weight of whole polished kernel Weight of paddy X Paddy length (mm) The length of randomly selected ten spikelets was measured in terms of millimeters by graph method. 5. Paddy breadth (mm) The breadth of randomly selected ten spikelets was measured in terms of millimeters by graph method. 6. Paddy L/B ratio The length/breadth ratio of randomly selected ten spikelets was calculated by dividing respective length with breadth.

53 37 7. Brown rice length (mm) The length of randomly selected ten hulled spikelets was measured in terms of millimeters by graph method. 8. Brown rice breadth (mm) The breadth of randomly selected ten hulled spikelets was measured in terms of millimeters by graph method. 9. Brown rice L/B ratio The length/breadth ratio of randomly selected ten hulled spikelets was calculated by dividing respective length with breadth. 10. Kernel length (mm) The length of randomly selected ten milled spikelets was measured in terms of millimeters by graph method. 11. Kernel breadth (mm) The length of randomly selected ten milled spikelets was measured in terms of millimeters by graph method. 12. Kernel L/B ratio The length/breadth ratio of randomly selected ten milled spikelets was calculated by dividing respective length with breadth. 13. Kernel length after cooking (mm) The length of randomly selected ten cooked spikelets was measured in terms of millimeters by graph method. 14. Kernel breadth after cooking (mm) The breadth of randomly selected ten cooked spikelets was measured in terms of millimeters by graph method. 15.Cooked rice L/B ratio The length/breadth ratio of randomly selected ten cooked spikelets was calculated by dividing respective length with breadth.

54 Elongation ratio Procedure for workout of elongation ratio is given in Annexure- VI. This was calculated by the following formula: Elongation ratio =Length of cooked kernel / Length of raw kernel 17. Alkali Spreading Value or Gelatinization Temperature The alkali spreading value was measured in terms of alkali dis-integration using a 7 point numerical spreading scale as suggested by Little et al., (1958). Six milled rice kernels were evenly placed in petridishes containing 1.7% KOH solution at 30 0C for 23 hours and the spreading scale was recorded. The procedure to work out ASV & GT and spreading scale and classification of alkali spreading value and gelatinization temperature is given in (Annexure-VII): Score Spreading scale 1 Kernel not affected 2 Kernel swollen 3 Kernel swollen, collar complete and narrow 4 Kernel swollen, collar complete and wide 5 Kernel split or dis-integration, collar complete and wide 6 Kernel dispersed, merging with collar 7 Kernel completely dispersed and intermingled Classification Alkali spreading value (ASV) 1-2 Low High >74 0C Gelatinization temperature (GT) 3 Low, intermediate High, intermediate 4-5 Intermediate Intermediate (70 0C 74 0C) 6-7 High Low (55 0C 69 0C) 3.5 Statistical Analysis The data recorded on 24 crosses and 13 parents with checks for agromorphological and quality characters were subjected to the following analysis.

55 Analysis of variance Source of Degree Variation freedom Replications r-1 of Mean Sum of Squares Mr Expected Mean Treatments t-1 Mt σ e2 + r σ g 2 Error (r-1) (t-1) Me σ e 2 The mean data were subjected to variance analysis and test of significance as per the method of Fisher (1935). r = Number of replication, t = Number of treatment Parameters of variation Mean Mean is the average value of observation of genotypes of a series. It represents the standard average value over fluctuation in the environment. Mean is calculated by the following formula: Where, = Σxi n Σxi = Summation of all the observations n = Total number of observations Range Range is the difference between the highest and the lowest value of a series of observations and thus provides the information about the extent of variability present in the genotypes. 3.6 Identification of Restorer and Maintainer Lines During the year 2015, pollen studies were carried out for their fertility/sterility of F1 plants. For this purpose, spikelets from the just emerged panicles of five randomly selected plants were collected in a vial containing 70 per cent alcohol. All the anthers from at least six spikelets were taken out with a forceps and placed on a glass slide with a drop of 1 per cent iodine potassium iodide (I2KI) stain. The anthers were gently crushed by using a needle to release the pollen grains. After removing the debris, a cover slip was placed and the slide was observed under the microscope. Five panicles of each testcross were covered with butter paper bags to avoid foreign pollen

56 contamination and were harvested at maturity for recording spikelet fertility/sterility observation. The criteria for classifying the parental Lines as maintainers, partial maintainers, partial restorers and restorers were used as proposed by Virmani et al. (1997). The categories of parental lines according to pollen fertility % and spikelet fertility % were given in Table 3.4 and their images are given in Plate 3.4 Table 3.4: The criteria for classifying the parental lines as proposed by Virmani et al. (1997) 40 Pollen fertility (%) Spikelet fertility (%) Category Maintainers Partial maintainers Partial restorers >80 >75 Restorers 3.7 Heterosis Heterosis for each trait was worked out by utilizing the overall mean of each hybrid over replications for each trait. The mean data of isogenic maintainer lines (of respective CMS lines) were used as values for female parents. Relative heterosis was estimated as per cent deviation of hybrid value from its mid parental value. The formula used for estimating mid-parent heterosis is as under: Where, di = F1 MP MP x 100 di = Heterosis over mid parental value (relative heterosis) F1 = Mean hybrid performance, and MP = Mid-parental value i.e., the arithmetic mean of two parents involved in the respective cross combination. Heterobeltiosis was, calculated at the deviation of hybrid from the better parent as under:

57 41 dii = F1 BP BP x 100 Where, dii = Heterobeltiosis i.e. heterosis over better parent, BP = Average performance of better parent in the respected cross combination. Standard heterosis was, calculated at the deviation of hybrid from the check variety as under: F1 SH diii = x 100 SH Where, diii = Standard heterosis i.e. heterosis over check parent, SH = Average performance of standard check The significance of different types of heterosis was carried out by adopting t test as suggested by Nadarajan and Gunasekaran (2005). t (relative heterosis) = F1ij - MPij SE t (heterobeltosis ) = F1ij - BPij SE t (Standard heterosis) = F1ij - CVij SE F1ij = Mean of i, jth cross MPij = Mid parental value for i, jth cross BPij = Better parental value of i, jth cross CVij = Standard parental value of i, jth cross SE = Standard error of heterosis

58 3.8 Combining ability analysis Combining ability analysis was carried out by the method suggested by Kempthorne (1957). Mean sum of squares that arises due to different sources of variation were estimated and their expected genetic values were calculated. A model analysis of variance (ANOVA) table for Line x tester analysis is given below: 42 ANOVA table for line x tester Analysis Source of variation Degree of freedom Sum of squares Mean sum of squares Replications (r- 1) SSR - - Hybrids SS(h) (lt 1) SS(h) - - Lines Testers (l-1) (Cov. HS) (t-1) (Cov. HS) Expected mean sum of squares SS ( l ) M l Me + r (Cov. FS 2 Cov. HS) + rt (Cov. HS) SS ( t ) Mt Me + r (Cov. FS 2 Cov. HS) + rl (Cov. HS) Lines x testers (l-1) (t-1) SS (l x t) M (l x t) Me + r (Cov. FS 2 Error (r-1)(lt-1) ESS Me - Total (rlt-1) Cov. HS) Where, r = number of replications l = number of lines t = number of testers Estimation of full sib s and half sib s covariance was calculated from, following formula: Ml+Mt 2M (1 x t) Cov (HS) = r(l x t) Cov (FS) = Me+Ml+ M (1 x t) 3 Me + 6r Cov (HS) r (l x t) Cov (HS) 3r

59 43 Cov (HS) and Cov (FS) were utilized to estimate variance due to general combining ability (GCA) and variance due to specific combining ability (SCA) as under: Variance of GCA = Cov (HS) Variance of SCA = Cov (FS) 2 Cov (HS) Estimation of General Combining Ability (GCA) and Specific Combining Ability (SCA) effects The GCA and SCA effect of ijkth observations were estimated by adopting the following model xijk = + gi + gj+ sij + ejik Where, xijk = GCA or SCA effect of ith. Line, jth. Tester, ijth. Interaction and error of jikth. observation = population mean gi = GCA effect of ith line gj = GCA effect of jth line sij = SCA effect of hybrid of ith line with jth tester ejik = Error effect associated with ijkth observation i = Number of lines j = Number of testers k = Number of replications The individual effect of GCA and SCA were estimated from the data obtained from two way table of lines vs testers as given below:

60 44 Two way table for lines vs testers: Lines Testers Total xij Xi Total x.j x x rlt gi = xi.. _ x rt rlt (check gi = 0) gi = xj.. Rl _ X rlt (check gi = 0) sij = xj.. _ x _ x.j. _ x R rt rl rlt Where, {check sij = sij = sij = 0} x = Total of all hybrid combination xi = Total of ith line over t testers and r replications x.j. = Total of jth tester over l lines and r replications and Xij = Total of the hybrid between ith line and jth tester over r replications. Significance of GCA effects of lines is tested as: Significance t = Gi S.E.(gi) of GCA effects of testers is tested as: t = Gj S.E.(gj)

61 45 Significance of SCA effects of hybrids is tested as: t = gij S.E. (Sij) The standard error pertaining to GCA and SCA effects were worked out from the square root of error variance effects as given below: (i) Standard error for testing the GCA effects of lines: S. E. (gi) = (ii) Standard error for testing the significance of difference between GCA effects of two lines: S. E.( gi gj ) = (iii) Standard error for testing the GCA effects of testers: S. E. (gj ) = (iv) Standard error for testing significance of difference between GCA effects of two testers: S. E. (Sij) = (v) Standard error for testing the SCA effects of hybrids: S. E. (Sii)= (vi) Standard error for testing the significance of difference between SCA effects of two lines: S. E. ( Sij Skl) =

62 CHAPTER - IV RESULTS AND DISCUSSION The main aim of any plant breeding programme is to develop special high yielding hybrids. To accomplish this, the breeding programme can efficiently be planned with prior knowledge of the genetic makeup of complex quantitative character yield and its attributes. It is therefore necessary to examine the genetic architecture of various quantitative and quality characters in relation to breeding behaviour of the genetic material available. Exploitation of heterosis and hybrid vigour is an important method of crop improvement adopted in many of the crops all over the world. In order to exploit, choice of suitable parent is an important step. The selection of parent depends on factors like per se performance of the parent and their combining ability. The concept of general and specific combining ability (Sparague and Tatum, 1942) helps the breeder in assessing many of the lines to be used as parent in the production of hybrids and also in identifying superior hybrid and hybrid having additive and non- additive genes. It is therefore, necessary to assess the genetic potentialities of the parent in hybrid combination through systematic studies in relation to general and specific combining abilities which are due to additive and non-additive gene action, respectively. In this direction, the Line x Tester analysis had proved as a very useful tool to work out the combining ability of parent. The knowledge of combining ability provides a useful clue for selection of desirable parents for development of superior hybrids. Thus, the information regarding heterosis, combining ability and nature of gene action are the basic requirements for a thorough understanding of genetic architecture of yield, yield attributing traits and quality traits. Keeping in view, the importance of aerobic condition in terms of climate change, aerobic hybrid improvement research programmed planned. The available literature indicated the possibility of exploiting heterosis for realizing higher yield potentiality. The findings of the present investigation entitled Identification of suitable rice hybrids adaptable to aerobic condition. involving three CMS lines and eight testers along with 24 F 1 s hybrids for their assessment of mean performance, identification of 46

63 47 maintainers and restorers, heterosis and combining ability effects in rice are described in detail under the following heads: 1. Mean performance of genotypes for different characters taken under study. 2. Identification of maintainer(s) and restorer(s). 3. Heterosis studies. 4. Combining ability estimates Mean performance of genotypes for different characters taken understudy The observations were recorded for the 37 genotypes i.e. 11 parents, 24 hybrids and two checks in three replications for 35 different quantitative and quality characters and were used for calculation of the mean performance. The observations were first averaged for five plants taken randomly for each genotype in each replication and further were averaged over three replications Mean performance of parents The mean performance of parents for different quantitative and quality characters is presented in Table 4.1. The mean performance of different characters is described as below: Agro-morphological characters 1. Days to 50 % flowering The mean performance of days to 50 % flowering ranged from (IR A) to 94 days (CRMS-31A), with overall mean of 97 days. Among the lines, IR79156A (84.00 days) flowered early followed by IR 58025A (92 days) whereas CRMS 31A (94 days) flowered late as compared to the mean for lines (97 days). Among Testers, AP-16 (110 days) flowered late as compared to the testers mean of 103 days. In checks, Indira barani dhan flowered early (86 days) as compare to overall parental mean (97 days) while Indira sona flowered early (90 days) as compare to overall parental mean of days to 50% flowering.

64 48 2. Plant height (cm) The plant height ranged from cm (IR 58025A) to cm R with an overall average mean of cm. Among the lines, IR 58025A recorded lowest plant height (80.13 cm) while CRMS31A (85.90 cm) noted highest plant height with an average of cm. Among the male parents, R recorded lowest plant height (85.67 cm) while R recorded highest value ( cm) with an average of 91.27cm. In checks, Indira barani dhan has more dwarf stature (81.23 cm) as compare to overall parental mean (89.89 cm), while Indira Sona shows semi tall stature ( cm) as compare to overall parental mean. 3. Productive tillers per plant The mean of productive tillers per plant was ranged from 6.57 (R ) to (IR79156A) with the overall parental mean of Among the lines, IR79156A (13.50) recorded higher mean value while the line CRMS 31A (8.60) recorded lowest with the average mean Among the testers, R (8.57) recorded highest mean value for the trait followed by Reg-1649 (8.00) whereas tester R , R showed lowest mean (6.57) for this trait with an average value of In the checks, Indira barani dhan (8.03) and Indira Sona (8.23) both have moderate productive tillers per plant as compare to overall parental mean of Panicle length (cm) The mean of panicle length ranged from (AP-16) to cm (IR58025A) with an overall parental mean of cm. Among lines, IR58025A showed highest panicle length (27.90 cm) and line IR 79156A showed lowest (26.03 cm) mean value with an overall mean of cm. Among the testers, highest mean value (23.90 cm) showed by R followed by R (23.80) and R (23.13) with an average of cm. In the checks, Indira Sona showed higher panicle length (22.20 cm) as compare to overall parental mean of cm whereas Indira barani dhan (18.93 cm) showed lesser panicle length as compare to overall parental mean.

65 49 Table 4.1.1(a) : Mean performance of parents for different agro-morphological characters PARENTS Agro-morpholigical character LINE/ FEMALE IR58025A IR CRMS-31A AVERAGE TESTERS/MALES R R R R R AP AP Reg AVERAGE CHECKS Indira barani dhan indira sona AVERAGE OVERALL PARENTAL AVERAGE LOWEST RANGE HIGHEST RANGE C.D SE(m) SE(d) C.V Days to 50% flowering, 2.Plant height (cm), 3. Productive tillers per plant, 4. Panicle Length(cm) 5. Total number of spikelets/panicle, 6. Number of sterile spikelets/panicle, 7. Number of Fertile spikelets/panicle 8. Spikelet fertility (%)

66 50 PARENTS Agro-morpholigical character LINE/ FEMALE IR58025A IR CRMS-31A AVERAGE TESTERS/MALES R R R R R AP AP Reg AVERAGE CHECKS Indira barani dhan indira sona AVERAGE OVERALL PARENTAL AVERAGE LOWEST RANGE HIGHEST RANGE C.D SE(m) SE(d) C.V Pollen fertility (%), 10. Test weight (g), 11. Grain Yield (g) per plant, 12. Biological Yield (g) per plan, 13. Harvest index (%), 14. Flag leaf width (cm), 15. Chlorophyll content, 16. Relative water content

67 51 Table 4.1.1(b) : Mean performance of parents for different quality characters PARENTS QUALITY CHARACTERS LINE/ FEMALE IR58025A IR CRMS-31A AVERAGE TESTERS/MALES R R R R R AP AP Reg AVERAGE CHECKS Indira barani dhan Indira sona AVERAGE OVERALL PARENTAL AVERAGE LOWEST RANGE HIGHEST RANGE C.D SE(m) SE(d) C.V Hulling %, 2- Milling %, 3 - Head rice recovery (%), 4 - Paddy length (mm, 5 -Paddy breadth (mm) 6- Paddy l/b ratio, 7 - Brown rice length(mm), 8 - Brown rice breadth(mm

68 52 PARENTS QUALITY CHARACTERS LINE/ FEMALE IR58025A IR CRMS-31A AVERAGE TESTERS/MALES R R R R R AP AP Reg AVERAGE CHECKS Indira barani dhan Indira sona AVERAGE OVERALL PARENTAL AVERAGE LOWEST RANGE HIGHEST RANGE C.D SE(m) SE(d) C.V Brown rice l/b ratio, 10 - Kernel length (mm), 11- Kernel breadth (mm), 12- Kernel l/b ratio, 13- Kernel length after cooking (mm), 14- Kernel breadth after cooking (mm), 15- Cooked rice l/b ratio, 16-Elongation ratio, 17- Alkali spreading value

69 53 5. Total spikelets per panicle The mean of total spikelet per panicle ranged from 63 (R ) to 182 (CRMS31A) with an overall parental mean of 113. Among lines, CRMS31Arecorded highest number of spikelet per panicle (182) followed by IR58025A (168) and IR79156A (137) with an average mean of Among testers, Reg-1649 recorded highest number of spikelet per panicle (131) followed by R (118), whereas R recorded lowest number of spikelets per panicles (62.67) with an average mean of 86. In checks, Indira sona showed higher number of spikelets per panicle (143) as compare to overall parental mean of (113) while Indira barani dhan showed lower number of spikelets per panicle (108) as compare to overall parental mean. 6. Sterile spikelets per panicle The mean of sterile spikelets per panicle ranged from 19 (AP-18) to 85 (IR58025A) with an overall parental mean of 38. Among the lines, IR58025A showed highest (85) sterile spikelets per panicle followed by IR79156 A (53) and CRMS31A (49) with an average of 62. Among the testers, highest mean value (29) was recorded for Reg-1649 followed by R (26), whereas lowest mean value (19) was recorded for AP-18 with an average mean of 24. In checks, Indira Sona showed higher sterile spikelet per panicle (60) and Indira barani dhan (27) showed lower sterile spikelets per panicle as compare to overall parental mean of Fertile spikelets per panicle The mean value for filled spikelets per panicle among the parents ranged from 38 (R ) to 132 (CRMS 31A) with an overall parental mean of 75. Among the lines, CRMS 31A (132.10) showed highest filled spikelets per panicle followed by IR79156 A (83) and IR58025A (83) with an average mean of 100. Among the testers, Reg-1649 (102) showed highest fertile spikelets per panicle followed by R (92) whereas tester R (38) showed lowest fertile spikelets per panicle with an average of 62. In the checks, Indira sona showed highest fertile spikelets per panicle (83) overall parental mean of of while Indira

70 54 barani dhan (81) also showed higher fertile spikelets per panicle overall parental mean of Spikelet fertility (%) The mean value for spikelet fertility percentage ranged from % (IR58025A) to % (R ) with overall parental mean of %. Among the testers, higher spikelet fertility percentage was noted for R (78.53 %) followed by Reg-1649 (77.81%), whereas R showed lowest value (61.17 %) with an average of 70.34%. In checks, Indira barani dhan (74.46 %) showed higher spikelet fertility % and Indira sona (57.62 %) showed lower spikelet fertility percentage as compare to overall parental mean of %. 9. Pollen fertility percentage The mean of pollen fertility percentage ranged from 0.00 % (CRMS31A) to % (Indira Sona) with an overall parental mean of %. All the CMS lines were showed 0.00 % pollen fertility percent. Among testers, R showed highest pollen fertility percentage (81.10%) followed by R (80 %), whereas Reg-1649 showed lowest pollen fertility percentage (44.03 %) with an average mean of testers being 68 %. In the checks, Indira sona (97.53 %) and Indira barani dhan (84.50 %) both showed higher pollen fertility percentage as compare to overall parental mean of %. 10. Test weight (g) The mean of 100 seeds weight ranged from g (CRMS31A) to 24 g (R ) with an overall parental average of g. Among the lines, IR79156A showed highest mean value (22.57 g) and lowest in CRMS31A (18.67 g) with an average of g. Among the testers, R showed highest mean value (24 g) followed by Reg-1649 (23.90 g), whereas R (20.20 g) showed lowest test weight value with an average of g. In the checks, Indira sona showed higher test weigh (23.40 g) than overall parental average of g while the Indira brani dhan (19.73 g) showed lower test weigh as compare to overall parental average.

71 Grain yield per plant (g) The mean value for the grain yield per plant, ranged from g (IR58025A) to g (Indira sona) with overall parental mean of g. Among the lines, highest mean value was recorded by CRMS31A (16.23 g) followed by IR79156A (12.70 g) and IR58025A (11.20 g) with an average mean of g. Among the testers, highest mean value for the trait was recorded by R (23.30 g) followed by R (23 g), whereas R (20.10 g) showed lowest grain yield per plant with an average of g. In checks, Indira Sona (27.23 g) showed higher grain yield per plant and Indira barani dhan(19.17) showed lower grain yield/plant as compare to overall parental mean of g. 12. Biological yield per plant (g) The mean of biological yield ranged from g (AP-16) to g (Indira sona) with an overall parental mean of g. Among lines, IR58025A showed highest biological yield per plant (49.73 g) followed by IR79156A (48.37 g) whereas CRMS31A showed lowest biological yield per plant (47.17 g) with an average mean of g. Among testers, r showed highest biological yield per plant (49 g) followed by R (48.33 g) and R (47 g), whereas AP-16 showed lowest biological yield per plant (33.60 g) with an average mean of testers being g. In checks, Indira sona showed higher biological yield per plant (53 g) than overall parental mean of g while Indira barani dhan (41.83g) showed lower biological yield per plant as compare to overall parental mean. 13. Harvest Index (%) The mean of harvest index in parents, ranged from 22.51% (IR58025A) to % (AP-16) with an overall average of %. Among the lines, CRMS31A showed highest mean value (34.43%) and lowest in IR58025A (22.51%) with an average of 27.74%. Among the testers, AP-16 (66.76%) showed highest mean value followed by R (58.93%), whereas R showed lowest harvest index (43 %) with an average of %. In checks, Indira sona (51.37 %) showed higher and Indira barani dhan (45.85 %) both showed lower harvest index as compare to overall parental average of %.

72 Flag leaf width (cm) The mean of flag leaf width ranged from 1.23 cm (Indira sona) to 1.60 cm (Indira barani dhan) with an overall parental mean of 1.36 cm. Among lines, IR79156A showed shortest flag leaf width (1.27 cm), whereas IR 58025A shows maximum flag leaf width (1.37 cm) with an average mean of 1.31 cm. Among testers, R showed shortest flag leaf width (1.30 cm), whereas R and AP-16 showed the longest flag leaf width (1.43 cm) followed by R (1.40 cm) with an average mean of 1.37 cm. In the checks, Indira Sona shows shorter flag leaf width (1.23 cm) and Indira barani dhan (1.60) show more flag leaf width as compare to overall parental mean 1.40 cm. 15. Chlorophyll Content The mean of Chlorophyll content ranged from (Indira barani dhan) to (IR79156A) with an overall average of Among the lines, IR 79156A has highest chlorophyll content (43.27) whereas IR58025A has lowest chlorophyll content (39.47) with an average of Among the testers, R has highest value chlorophyll content (39.70), whereas R has lowest chlorophyll content (36.23) with an average of In checks, Indira Sona (31.40) and Indira barani dhan has lower chlorophyll content (25.63) as compare to overall parental mean(36.91). 16. Relative water content The mean of Relative water content from (R ) to (IR79156A) with an overall average of Among the lines, IR 79156A has highest Relative water content (92.40) whereas IR58025A has lowest relative water content (85.77) with an average of Among the Testers, R has highest value relative water content (71.37) whereas R has lowest relative water content (51.87) with an average of In checks, Indira barani dhan (77.33) has highest value of relative water content and Indira Sona has lower relative water content (69.00) as compare to overall parental mean (73.71).

73 57 QUALITY CHARACTERS 1. Hulling (%) The mean of hulling percentage ranged from (R ) to 82.52% (IR 58025A ), with an overall parental mean of 62.77%. Among the lines, IR 58025A recorded highest mean value (82.52%) followed by CRMS31A (81.30%) and IR79156A (70.05%) with an average of 80.96%. Among the testers, AP-18 exhibited highest mean value (53.79%) followed by AP-16 (53.74%), whereas R exhibited lowest mean value (48.49 %) with an average of %. In checks, Indira Sona (73.71 %) showed higher hulling % as compare to overall parental average of 62.77% while Indira barani dhan (68.41 %) also showed higher hulling % as compare to overall parental average. 2. Milling (%) The mean of milling percentage ranged from % (R ) to 76.81% (IR58025A) with an overall parental mean of 56.03%. Among the lines, IR58025A recorded highest mean value (76.81%) followed by IR79156A (75.54%) with an average of 75.20%. Among the testers, R exhibited highest mean value (47.25 %) followed by R (46.98%) and R (46.21%), whereas R exhibited lowest mean value (43.87%) with an average of %. In checks, Indira Sona (62.57 %) and Indira barani dhan (62.05 %) both showed higher milling % as compare to overall parental average of %. 3. Head rice recovery (%) The mean of head rice recovery (HRR) ranged from 35.52% (R ) to 62.50% (IR79156A) with an overall parental mean of 50.07%. Among the lines, IR79156A recorded highest mean value (62.50%) followed by CRMS31A (59.26%) and IR58025A (58.19%) with an average of %. Among the testers, R exhibited highest mean value (50.71%) followed by Reg-1649 (48.49%), whereas R showed lowest mean value (35.52 %) with an average of %. In checks, Indira Sona (56.60 %) showed higher and Indira barani dhan (46.4 %) showed lower head rice recovery % as compare to overall parental average of %.

74 58 4. Paddy length (mm) The mean of paddy length ranged from 7.27 mm (Reg-1649) to mm (IR58025A) with an overall parental mean of 8.92 mm. Among the lines, IR58025A recorded highest mean value (10.03 mm) followed by IR79156A (9.83 mm) and CRMS 31A (9.24mm) with an average of 9.70 mm. Among the testers, R exhibited highest mean value (9.33 mm) followed by AP-18 (9.30 mm) and R (9.03mm), whereas Reg-1649 showed lowest paddy length (7.27 mm) with an average of 8.35 mm. In checks, Indira barani dhan(9.66 mm) and Indira sona (9.56 mm) both showed higher paddy length as compare to overall parental mean of 8.92 mm. 5. Paddy breadth (mm) The mean of paddy breadth ranged from 2.07 mm (R ) to 2.53 mm (Indira sona) with an overall parental mean of 2.26 mm. Among the lines, IR79156A recorded highest mean value (2.42mm) followed by IR58025A(2.33) and CRMS31A (2.24 mm) with an average of 2.33 mm. Among the testers, AP-16 (2.30) followed by Reg-1649 (2.23 mm), whereas R and AP-18 showed lowest paddy breadth (2.07mm) with an average of 2.17 mm. In checks, Indira sona (2.53 mm) showed higher paddy breadth as compare to overall parental mean of 2.42 mm, while Indira barani dhan (2.30 mm) showed lower paddy breadth as compare to overall parental mean. 6. Paddy L/B ratio The mean of paddy L/B ratio ranged from 3.20 (AP-16) to 4.50 (AP-18) with an overall parental mean of Among the lines, IR58025A recorded highest mean value (4.31) followed by CRMS31A (4.12) and IR79156A (4.07) with an average of 4.17 Among the testers, AP-18 exhibited highest mean value (4.50) followed by R , (4.25), whereas AP-16 showed lowest paddy L/B ratio (3.20) with an average of In the checks, Indira barani dhan showed higher paddy L/B ratio (4.20) as compare to overall parental mean of 3.96 while Indira sona (3.78) showed lower paddy L/B ratio as compare to overall parental mean.

75 59 7. Brown rice length (mm) The mean of brown rice length ranged from 5.43 mm (Reg-1649) to 7.63 mm (Indira barani dhan) with an overall parental mean of 6.82 mm. Among the lines, IR79156A recorded highest mean value (7.41 mm) followed by IR58025A (7.32 mm) and CRMS31A (6.53 mm) with an average of 7.09 mm. Among the testers, R exhibited highest mean value (7.23 mm) followed by R (7.20mm) and AP-18 (7.20 mm), whereas Reg-1649 exhibited lowest mean value (5.43 mm) with an average of 6.52 mm. In the checks, Indira barani dhan (7.63 mm) and Indira sona (7.08mm) both showed higher brown rice length as compare to overall parental mean of 6.82 mm. 8. Brown rice breadth (mm) The mean of brown rice breadth ranged from 1.67 mm (R ) to 2.17 mm (AP-16 and Indira sona) with an overall parental mean of 1.96 mm. Among the lines, IR79156A recorded highest mean value (1.86 mm) followed by IR58025A (1.81 mm) and CRMS31A (1.75 mm) with an average of 1.81mm. Among the testers, AP-16 were exhibited highest mean value (2.17 mm) followed by Reg-1649 (2.10 mm), whereas R showed lowest mean value (1.67 mm) with an average of 1.97 mm. In checks, Indira sona exhibited higher mean value (2.17 mm) as compare to overall parental mean of 2.26 mm, while Indira barani dhan (2.07 mm) also showed higher brown rice breadth as compare to overall parental mean. 9. Brown rice L/B ratio The mean of brown rice L/B ratio ranged from 2.59 (Reg-1649) to 4.04 (IR58025A) with an overall parental mean of Among the lines, IR58025A recorded highest mean value (4.04) followed by IR79156A (3.99) and CRMS31A (3.72) with an average of Among the testers, R exhibited highest mean value (3.92) followed by R (3.56), whereas Reg-1649 showed lowest mean value (2.59), with an average of In the checks, Indira barani dhan (3.69) showed higher and Indira sona (3.27) both showed lower brown rice L/B ratio as compare to overall parental mean of 3.51.

76 Kernel length (mm) The mean of kernel length ranged from 4.43 mm (AP-18) to 7.16 mm (IR79156A) with an overall parental mean of 5.77 mm. Among the lines, IR79156A recorded highest mean value (7.16 mm) followed by IR58025A (6.38 mm) and CRMS31A (6.32 mm) with an average of 6.62 mm. Among the testers, R exhibited highest mean value (6.27 mm) followed by R (6.03 mm) and R (5.37 mm), whereas AP-18 showed lowest mean value (4.43) with an average of 5.33 mm. In the checks, Indira sona (6.37 mm) showed higher kernel length as compare to overall parental mean of 5.77 mm while Indira barani dhan (5.57 mm) showed as similar as overall parental mean. 11. Kernel breadth (mm) The mean of kernel breadth ranged from 1.57 mm (R ) to 2.07 mm (Indira Sona) with an overall parental mean of 1.85 mm. Among the lines, IR79156A recorded highest mean value (1.76 mm) followed by CRMS31A (1.66 mm) and IR58025A (1.64 mm) with an average of 1.69 mm. Among the testers, AP-16 and Reg-1649 exhibited highest mean value (2.03 mm) followed by R and AP-18 (1.93 mm), whereas R showed lowest mean value (1.60 mm) with an average of 1.87 mm. In checks, Indira sona (2.07 mm) and Indira barani dhan (2.00mm) both showed higher kernel breadth as compare to overall parental mean of 1.85 mm. 12. Kernel L/B ratio The mean of Kernel L/B ratio ranged from 2.30 (AP-18) to 4.08 (IR79156A) with an overall parental mean of Among the lines, IR79156A recorded highest mean value (4.08) followed by IR58025 A (3.90) and CRMS31A (3.81) with an average of Among the testers, R exhibited highest mean value (3.88) followed by R (3.36) and R (3.32), whereas AP-18 showed lowest mean value (2.30) with an average of In the checks, Indira Sona (3.08) and Indira barani dhan (2.79) both showed lower kernel L/B ratio as compare to overall parental mean of 3.16.

77 Kernel length after cooking (mm) The mean of kernel length after cooking ranged from 6.80 (Reg-1649) to 9.82 mm (CRMS31A) with an overall parental mean of 8.24 mm. Among the lines, CRMS31A recorded highest mean value (9.82 mm) followed by IR79156A (8.34 mm) and IR58025A (8.24 mm) with an average of 8.80 mm. Among the testers, R exhibited highest mean value (9.13 mm) followed by R (8.53 mm) and R (8.24 mm), whereas Reg-1649 showed lowest mean value (6.80 mm) with an average of 7.93 mm. In the checks, Indira sona (8.73 mm) showed higher and Indira barani dhan (8.10 mm) showed lower kernel length after cooking as compare to overall parental mean of 8.24 mm. 14. Kernel breadth after cooking (mm) The mean of kernel breadth after cooking ranged from 2.50 (AP-16) to 3.60 mm (Reg-1649) with an overall parental mean of 2.96 mm. Among the lines, IR58025A recorded highest mean value (3.04 mm) followed by CRMS31A (2.92 mm) and IR79156A (2.79 mm) with an average of 2.92 mm. Among the testers, Reg-1649 exhibited highest mean value (3.60 mm) followed by R (3.27mm) and R (3.23 mm) with an average of 3.10 mm. In checks, Indira sona (2.67 mm) and Indira barani dhan (3.12 mm) both showed higher kernel breadth after cooking as compare to overall parental mean of 2.82 mm. 15. Cooked rice L/B ratio The mean of Kernel cooked rice L/B ratio ranged from 1.89 (Reg-1649) to 3.36 (CRMS31A) with an overall parental mean of Among the lines, CRMS31A recorded highest mean value (3.36) followed by IR79156A (2.99) and IR58025A (2.71) with an average of Among the testers, AP-16 exhibited highest mean value (3.32) followed by R (2.96) and R (2.69), whereas Reg showed lowest mean value (1.89) with an average of In the checks, Indira sona (3.28) showed higher cooked rice L/B ratio as compare to overall parental mean of 2.82 while Indira barani dhan (3.12) showed higher value as overall parental mean.

78 Elongation ratio The mean of elongation ratio ranged from 1.09 (IR79156A) to 1.60 (AP-16and R ) with an overall parental mean of Among the lines, CRMS31A recorded highest mean value (1.56) followed by IR58025A (1.10) and IR79156A (1.09) with an average of Among the testers, AP-16 and R exhibited highest mean value (1.60) followed by AP-18 (1.57), whereas R showed lowest mean value (1.33) with an average of In checks, Indira barani dhan (1.43) showed higher and Indira sona (1.37) showed lower elongation ratio as compare to overall parental average of Alkali spreading value/ Gelatinization temperature The general mean of Alkali spreading value/gelatinization temperature was ranged from 4 (IR58025A/Indira barani dhan) to 7.00 (CRMS31A/Reg-1649) with an average parental mean of Among the lines, CRMS31A recorded the highest value (7.00) followed by IR79156A (6.00) and IR58025A (4.00) with an average of Among the tester, Reg-1649 recorded highest mean value (7.00) followed by R and AP-16 (6.67), whereas R and AP-18 showed lowest mean value (5.67) with an average of In checks, Indira Sona (4.00) and Indira barani dhan (4.00) both showed lower Alkali spreading value/gelatinization temperature as compare to overall parental average of The good quality rice grains have intermediate alkali spreading value of (4-5) Mean performance of hybrids The mean performance of twenty one hybrids for different quantitative and qualitative characters is presented in Table 4.2. The mean performance of different characters is described as below: 1. Days to 50 % flowering Mean performance among the hybrids for days to 50% flowering ranged from (IR79156A/ R ) to 119 days (IR79156A/ Reg-1649) with an overall average of 101 days. Among the crosses with the line IR58025A, IR58025A/R (93.00 days) was recorded earliest flowering. Among the crosses with line IR 79156A, IR79156A/R (83.50 days) recorded earliest

79 63 flowering while crosses with the line CRMS 32A, CRMS 32A/RIL-62 (86.50 days) was recorded earliest flowering. Considering the performance among the entire cross combinations for this trait, four combinations viz., IR58025A/R , IR79156A/ R ,IR79156A/R and CRMS 31A/R were identified as good performing hybrids for days to 50% flowering. 2. Plant height (cm) Mean performance among the hybrids for plant height ranged from cm (IR58025A/R ) to cm (IR79156A/ AP-18) with an overall average of cm. Among the crosses with the line IR58025A, IR58025A/R (86.03 cm) recorded the lowest plant height, while crosses with line IR 79156A, IR 79156A/R (88.13 cm) recorded the lowest plant height and crosses with the line CRMS 31A, CRMS 31A/R (87.67 cm) recorded the lowest plant height. Considering the significant value of this trait among the entire cross combinations, three combinations viz., IR58025A/R , 79156A/R and CRMS31A/R were identified as good performing hybrids.

80 64 Table (a) : Mean performance of hybrids for different agro-morphological characters CROSSES Agro-morphological character IR58025A IR58025A/R IR58025A/R IR58025A/R IR58025A/R IR58025A/R IR58025A/AP IR58025A/AP IR58025A/Reg AVERAGE IR IR-79156/R IR-79156/R IR-79156/R IR-79156/R IR-79156/R IR-79156/AP IR-79156/AP IR-79156/Reg AVERAGE CRMS-31A CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/AP CRMS-31A/AP CRMS-31A/Reg AVERAGE OVERALL AVERAGE LOWEST RANGE HIGHEST RANGE C.D SE(m) SE(d) C.V Days to 50% flowering, 2.Plant height (cm), 3. Productive tillers per plant, 4. Panicle Length(cm), 5. Total number of spikelets/panicle, 6. Number of sterile spikelets/panicle, 7. Number of Fertile spikelets/panicle, 8. Spikelet fertility (%)

81 65 CROSSES Agro-morphological character IR58025A IR58025A/R IR58025A/R IR58025A/R IR58025A/R IR58025A/R IR58025A/AP IR58025A/AP IR58025A/Reg AVERAGE IR IR-79156/R IR-79156/R IR-79156/R IR-79156/R IR-79156/R IR-79156/AP IR-79156/AP IR-79156/Reg AVERAGE CRMS-31A CRR CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/AP CRMS-31A/AP CRMS-31A/Reg AVERAGE OVERALL AVERAGE LOWEST RANGE HIGHEST RANGE C.D SE(m) SE(d) C.V Pollen fertility (%), 10. Test weight (g), 11. Grain Yield (g) per plant, 12. Biological Yield (g) per plan, 13. Harvest index (%), 14. Flag leaf width (cm), 15. Chlorophyll Content, 16. Relative water content

82 66 Table 4.1.2(b): Mean performance of hybrids for different quality characters CROSSES quality characters IR58025A IR58025A/R IR58025A/R IR58025A/R IR58025A/R IR58025A/R IR58025A/AP IR58025A/AP IR58025A/Reg AVERAGE IR IR-79156/R IR-79156/R IR-79156/R IR-79156/R IR-79156/R IR-79156/AP IR-79156/AP IR-79156/Reg AVERAGE CRMS-31A CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/AP CRMS-31A/AP CRMS-31A/Reg AVERAGE OVERALL AVERAGE LOWEST RANGE HIGHEST RANGE C.D SE(m) SE(d) C.V Hulling %, 2- Milling %, 3 - Head rice recovery (%), 4 - Paddy length (mm, 5 -Paddy breadth (mm) 6- Paddy l/b ratio, 7 - Brown rice length(mm), 8 - Brown rice breadth(mm)

83 67 CROSSES quality characters IR58025A IR58025A/R IR58025A/R IR58025A/R IR58025A/R IR58025A/R IR58025A/AP IR58025A/AP IR58025A/Reg AVERAGE IR IR-79156/R IR-79156/R IR-79156/R IR-79156/R IR-79156/R IR-79156/AP IR-79156/AP IR-79156/Reg AVERAGE CRMS-31A CRR CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/R CRMS-31A/AP CRMS-31A/AP CRMS-31A/Reg AVERAGE OVERALL AVERAGE LOWEST RANGE HIGHEST RANGE C.D SE(m) SE(d) C.V Brown rice l/b ratio, 10 - Kernel length (mm), 11- Kernel breadth (mm), 12- Kernel l/b ratio, 13- Kernel length after cooking (mm), 14- Kernel breadth after cooking (mm), 15- Cooked rice l/b ratio, 16-Elongation ratio, 17- Alkali spreading value

84 68 3. Productive Tillers / Plant The mean of the hybrids ranged from 5.27 (IR58025A/R ) to 9.33 (IR79156A / R ) with an overall average of Among the crosses with line IR58025A, IR58025A/ R and IR58025A/Reg hybrid recorded highest productive tillers / plant (8.33) followed by IR58025A/R (7.27). Among the crosses with IR79156A, IR79156A/ R Showed highest mean (9.33) followed by IR79156A/ R (9.27) while the crosses with line CRMS31A, CRMS31A/Reg-1649 recorded highest productive tillers / plant (8.53) followed by CRMS31A/ R (8.20). Among the entire cross combinations, four cross combinations viz., IR58025A/ R ,IR58025A/Reg-1649, IR79156A/ R and CRMS31A/ Reg-1649 were identified as good performing hybrids for productive tillers / plant. 4. Panicle Length (cm) The mean of the hybrids ranged from cm (IR58025A/R ) to cm (CRMS31A/R ) with an overall average of cm. Among the crosses with line IR58025A, IR58025A/ R hybrid recorded highest panicle length (24.73 cm) followed by IR58025A/R (24.60 cm). Among the crosses with IR79156A, IR79156A/ AP-18 showed highest mean (28.75 cm) followed by IR79156A/ R (28.65 cm), while the crosses with line CRMS32A, CRMS32A/ R recorded highest panicle length (25.90 cm) followed by CRMS31A/ R (24.07 cm). Among all the cross combinations, three cross combinations viz., IR58025A/ R , IR79156A/AP-18 and CRMS31A/ R were identified as good performing hybrids for panicle length.

85 69 5. Total spikelets per panicle Among hybrids, total spikelet per panicle ranged from 50 (CRMS31A/ R ) to 119 (CRMS31A/Reg-1649) with an overall mean of Among the crosses with line IR58025A, IR58025A/ Reg-1649 (116.67) recorded the highest spikelet per panicle followed by IR58025A/AP-16 (114.33) and IR58025A/ R (106.33). Among the crosses with IR79156A, IR79156A/AP-18 showed highest mean (117.33) followed by IR79156A/ R (115.67) and IR79156A/AP-16 (106.33) while the crosses with line CRMS31A, CRMS31A/ Reg-1649 recorded highest mean (119) followed by CRMS32A/ R (111.67) and CRMS31A/AP-16 (96.67). Among the entire cross combinations, three cross combinations viz., IR58025A/ Reg-1649, IR79156A/AP-18 and CRMS31A/ Reg-1649were identified as good performing hybrids for total spikelet per panicle. 6. Sterile Spikelets/Panicle The mean of the hybrids ranged from 15 (CRMS31A/R ) to 56 (IR58025A/Reg-1649) with an overall average of Among the crosses with line IR58025A, IR58025A/ AP-18 (20) hybrid recorded lowest sterile spikelets/panicle followed by IR58025A/ R (23.67). Among the crosses with IR79156A, IR79156A/R (20) showed lowest mean followed by IR79156A/ AP-18 (23.33) while the crosses with line CRMS31A, CRMS31A/ R (15) recorded lowest sterile spikelets/panicle followed by CRMS31A/ AP-16 (15.33). Among the entire cross combinations, three cross combinations viz., IR58025A/ AP-18, IR79156A/ R and CRMS31A/ R were recorded as good performing hybrids for sterile spikelets/ panicle. 7. Fertile Spikelets/Panicle The mean of the hybrids ranged from 30 (IR58025A/ R ) to (IR79156A/Reg-1649) with an overall average of 58.86

86 70 Among the crosses with line IR58025A, IR58025A/ R hybrid recorded highest fertile spikelets/panicle (80.00) followed by IR58025A/ R (75) and IR58025A/AP-16. Among the crosses with IR79156A, IR79156A/ Reg-1649 showed highest mean (81.33) followed by IR79156A/AP-16 (63.67) while the crosses with line CRMS31A, CRMS31A/ Reg-1649 recorded highest fertile spikelets/panicle (75.67) followed by CRMS31A/ R (75). Among all the cross combinations, three cross combinations viz., IR58025A/ Reg-1649, IR79156A/R and CRMS31A/ Reg-1649 were identified as good performing hybrids for fertile spikelets/panicle. 8. Spikelet fertility percentage Among hybrids, spikelet fertility % ranged from 47.58% (IR58025A/R ) to % (CRMS31A/ R ) with an overall mean of %. Among the crosses with line IR58025A, IR58025A/ R (76.05%) recorded the highest spikelet fertility percent followed by IR58025A/ R (75.33%) and IR58025A/AP-16 (72.65%). Among the crosses with IR79156A, IR79156A/ R (72.05%) showed highest mean followed by IR79156A/ Reg-1649 (69.40%) and IR79156A/AP-18 (66.59%) while the crosses with line CRMS31A, CRMS31A/ R (77.10%) recorded highest mean followed by CRMS31A/R (74.75%) and CRMS32A/ R (72.82%). Among the entire cross combinations, three cross combinations viz., IR58025A/ R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for spikelet fertility percentage. 9. Pollen Fertility percentage The mean of the hybrids ranged from 50.70% (IR58025A / R ) to 83.60% (CRMS31A / R ) with an overall average of 70.67%.

87 71 Among the crosses with line IR58025A, IR58025A/ R hybrid recorded highest pollen fertility (81.60 %) followed by IR58025A/ R (81.20 %). Among the crosses with IR79156A, IR79156A/ R showed highest mean (75 %) followed by IR79156A/AP-18 (73.70 %) while the crosses with line CRMS31A, CRMS31A/ R recorded highest pollen fertility (83.60 %) followed by CRMS31A/ R (82.77 %). Among all the cross combinations, three cross combinations viz., IR58025A/ R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for pollen fertility. 10. Test weight (g) Among hybrids, test weight ranged from g (CRMS31A/R ) to g (CRMS31A/R ) with an overall mean of g. Among the crosses with line IR58025A, IR58025A/Reg-1649 (22.60 g) recorded the highest test weight followed by IR58025A/AP-18 (22.27 g). Among the crosses with IR79156A, IR79156A/ R (23.03 g) showed highest mean followed by IR79156A/ Reg-1649, (22.77), while the crosses with line CRMS31A, CRMS31A/ R (23.97) recorded highest mean followed by CRMS31A/ Reg-1649 (23.83). Among the entire cross combinations, three cross combinations viz., IR58025A/Reg-1649, IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for test weight. 11. Grain Yield per plant (g) Among hybrids, grain yield per plant ranged from g (IR58025A/R ) to g (IR58025A/R ) with an overall mean of g. Among the crosses with line IR58025A, IR58025A/ R (24.83 g) recorded the highest grain yield per plant followed by IR58025A/ R (24.10 g) and IR58025A/AP-18 (21.77g). Among the crosses with

88 72 IR79156A, IR79156A/Reg-1649 (20.10 g) showed highest mean followed by IR79156A/ R (19.53 g) and IR79156A/ AP-16 (19.03 g) while the crosses with line CRMS31A, CRMS31A/ R (21.53g) recorded highest mean followed by CRMS31A/R (21.53 g) and CRMS31A/ R (21.33 g). Among the entire cross combinations, three cross combinations viz., IR58025A/ R , IR79156A/Reg-1649 and CRMS31A/ R were identified as good performing hybrids for grain yield per plant. 12. Biological Yield per plant (g) Among hybrids, biological yield per plant ranged from g (IR79156A/ R ) to g (IR79156A/ R ) with an overall mean of g. Among the crosses with line IR58025A, IR58025A/AP-16 (55.67 g) recorded the highest biological yield per plant followed by IR58025A/ R (53.67 g) and IR58025A/ R (53.33g). Among the crosses with IR79156A, IR79156A/Reg-1649 (49.63 g) showed highest mean followed by IR79156A/ R (45g) and IR79156A/ R (44.33 g), while the crosses with line CRMS31A, CRMS31A/ R (56 g) recorded highest mean followed by CRMS31A/ R (53.33 g) and CRMS31A/ R (49.67 g) Among the entire cross combinations, three cross combinations viz., IR58025A/AP-16, IR79156A/Reg-1649 and CRMS31A/ R were identified as good performing hybrids for biological yield per plant. 13. Harvest Index (%) Among hybrids, harvest index ranged from 32.13% (CRMS31A/ R ) to 59.19% (IR58025A/ R ) with an overall mean of 44.55%. Among the crosses with line IR58025A, IR58025A/R (59.19%) recorded the highest Harvest index followed by IR58025A/ R

89 (48.45%) and IR58025A/Reg-1649 (47.70%). Among the crosses with IR79156A, IR79156A/AP-18 (48.17%) showed highest mean followed by IR79156A/ R (47.23%) and IR79156A/AP-16 (46.54%) while the crosses with line CRMS31A, CRMS31A/ R (49.14%) recorded highest mean followed by CRMS31A/AP-18 (47.82%) and CRMS31A/ R (46.66%). Among the entire cross combinations, four cross combinations viz., IR58025A/ R , IR79156A/AP-18 and CRMS31A/ R were identified as good performing hybrids for harvest index. 14. Flag leaf width (cm) The mean of the hybrids ranged from 1.20 cm (IR79156A/ R ) to 1.77 cm (IR58025A/R ) with an overall average of 1.37 cm. Among the crosses with line IR58025A, IR58025A/ R hybrid recorded highest flag leaf width (1.77 cm) followed by IR58025A/ R (1.40 cm). Among the crosses with IR79156A, IR79156A/ AP-18 and IR58025A/Reg-1649 showed highest mean (1.40 cm) followed by IR79156A/R and IR79156A/R (1.30 cm) while the crosses with line CRMS31A, CRMS31A/ R recorded highest flag leaf width (1.60cm) followed by CRMS31A/AP-16(1.43) Among the entire cross combinations, four cross combinations viz., IR58025A/ R , IR79156A/AP-18, Reg and CRMS31A/ R were identified as good performing hybrids for flag leaf width. 15. Chlorophyll Content Mean performance among the hybrids for Chlorophyll content ranged from (IR79156A/AP-18) to (IR79156A/ R ) with an overall average of Among the crosses with the line IR58025A, IR58025A/ R showed highest chlorophyll content (40.60), while crosses with IR79156A, IR79156A/ R showed highest mean value (40.10) and crosses with line CRMS31A, CRMS31A/ R showed highest mean value (38.87).

90 74 Considering the significant value of this trait among the entire cross combinations, three combinations viz., IR58025A/ R , IR79156A/ and CRMS31A/ R were identified as good performing hybrids. 16. Relative water content The mean of the hybrids ranged from (IR79156A/ R ) to (CRMS31A/ R ) with an overall average of Among the crosses with line IR58025A, IR58025A/ R hybrid recorded highest relative water content (72.67 cm) followed by IR58025A/ AP- 18 (65.67). Among the crosses with IR79156A, IR79156A/ R followed by IR79156A/ R and IR79156A/AP-16 (57.50) while the crosses with line CRMS31A, CRMS31A/ Reg-1649 recorded highest relative water content (78.60) followed by CRMS31A/AP-16(1.43). Among the entire cross combinations, three cross combinations viz., IR58025A / R , IR79156A/ R and CRMS31A/ Reg-1649 were identified as good performing hybrids for relative water content. QUALITY CHARACTERS 1. Hulling % Among hybrids, hulling % ranged from % (IR58025A/R ) to 77.12% (IR79156A/R ) with an overall mean of %. Among the crosses with line IR58025A, IR58025A/R (71.33%) recorded the highest hulling % followed by IR58025A/R (70.83%). Among the crosses with IR79156A, IR79156A/ R (77.12%) showed highest mean followed by IR79156A/Reg-1649 (52.35 %) while the crosses with line CRMS31A, CRMS31A/ R (72%) recorded highest mean followed by CRMS31A/R (69.84%). Among the entire cross combinations, three cross combinations viz., IR58025A /R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for hulling %.

91 75 2. Milling % Among hybrids, milling % ranged from 41.95% (IR58025A/AP-16) to % (CRMS31A/ R ) with an overall mean of %. Among the crosses with line IR58025A, IR58025A/ R (65.73%) recorded the highest milling % followed by IR58025A/ R (63.57%). Among the crosses with IR79156A, IR79156A/ R (49.85%) showed highest mean followed by IR79156A/R (46.82 %), while the crosses with line CRMS31A, CRMS31A/R (51.74%) recorded highest mean followed by CRMS31A/R (47.82%). Among the entire cross combinations, three cross combinations viz., IR58025A/ R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for milling %. 3. Head rice recovery (%) Among hybrids, head rice recovery ranged from 33.54% (IR58025A/ R ) to 51.74% (CRMS31A/ R ) with an overall mean of %. Among the crosses with line IR58025A, IR58025A/ R (69.00%) recorded the highest head rice recovery followed by IR58025A/ R (48.51%). Among the crosses with IR79156A, IR79156A/ R (49.85%) showed highest mean followed by IR79156A/ R (44.24 %) while the crosses with line CRMS31A, CRMS31A/R (51.74%) recorded highest mean. Among the entire cross combinations three cross combinations viz., IR58025A/ R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for head rice recovery. 4. Paddy length (mm) Among hybrids, paddy length ranged from 6.37 mm (CRMS31A/AP-16) to 9.82 mm (IR58025A/R ) with an overall mean of 8.33 mm.

92 76 Among the crosses with line IR58025A, IR58025A/ R (9.82 mm) recorded the highest paddy length followed by IR58025A R and IR58025A/Reg-1649 (9.30 mm). Among the crosses with IR79156A, IR79156A/ R (9.69 mm) showed highest mean followed by IR79156A/Reg-1649 and IR79156A/ R (8.57 mm) while the crosses with line CRMS31A, CRMS31A/ R (10.70 mm) recorded highest mean followed by CRMS31A/R (9.71 mm) and CRMS31A/R (8.53 mm). Among the entire cross combinations, three cross combinations viz., IR58025A/ R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for paddy length. 5. Paddy breadth (mm) Among hybrids, paddy breadth ranged from 2.03 mm (CRMS31A/ R ) to 2.55 mm (CRMS31A/ R ) with an overall mean of 2.19 mm. Among the crosses with line IR58025A, IR58025A/ R (2.48 mm) recorded the highest paddy breadth followed by IR58025A/ R (2.41 mm). Among the crosses with IR79156A, IR79156A/ R (2.39 mm) showed highest mean followed by IR79156A/R (2.23 mm), while the crosses with line CRMS31A, CRMS31A/ R and recorded highest mean followed by CRMS31A/ R (2.42 mm). Among the entire cross combinations, three cross combinations viz., IR58025A/ R , IR79156A/ R , CRMS31A/ R , were identified as good performing hybrids for paddy breadth. 6. Paddy L/B ratio Among hybrids, paddy L/B ratio ranged from 3.03 (CRMS31A/AP-16) to 4.47 (IR79156A/Reg-1649) with an overall mean of Among the crosses with line IR58025A, IR58025A/ Reg-1649 (4.36) recorded the highest paddy L/B ratio followed by IR58025A/AP-18 (4.47). Among the crosses with IR79156A, IR79156A/R (4.08) showed highest mean followed

93 77 by IR79156A/ R (4.47), while the crosses with line CRMS31A, CRMS31A/ R (4.21) recorded highest mean followed by CRMS31A/ R (4.05). Among the entire cross combinations, three cross combinations viz., IR58025A/Reg-1649, IR79156A/Reg-1649 and CRMS31A/R were identified as good performing hybrids for paddy L/B ratio. 7. Brown Rice length (mm) Among hybrids, brown rice length ranged from 5.07 mm (IR58025A/AP-18) to 7.71 mm (IR58025A/R ) with an overall mean of 6.19 mm. Among the crosses with line IR58025A, IR58025A/ R (7.71mm) recorded the highest brown rice length followed by IR58025A/ R (7.65 mm). Among the crosses with IR79156A, IR79156A/ R (7.12 mm) showed highest mean followed by IR79156A/ Reg-1649(7.12 mm) while the crosses with line CRMS31A, CRMS31A/ R (7.20 mm) recorded highest mean followed by CRMS31A/ R (7.19 mm). Among the entire cross combinations, three cross combinations viz., IR58025A / R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for brown rice length. 8. Brown Rice breadth (mm) Among hybrids, brown rice breadth ranged from 1.37 mm (IR58025A/ R ) to 2.19 mm (IR58025A/ R ) with an overall mean of 1.90 mm. Among the crosses with line IR58025A, IR58025A/ R (2.19 mm) recorded the highest brown rice breadth followed by IR58025A/ Reg-1649 (2.13 mm). Among the crosses with IR79156A, IR79156A/ Reg-1649 and (2.13 mm) showed highest mean followed by IR79156A/R (2.08 mm), while the crosses with line CRMS31A, CRMS31A/ R (2.18 mm) recorded highest mean followed by CRMS31A/ R (2.30 mm).

94 78 Among the entire cross combinations, three cross combinations viz., IR58025A/ R , IR79156A/Reg-1649, and CRMS31A/ R were identified as good performing hybrids for brown rice breadth. 9. Brown Rice L/B ratio Among hybrids, brown rice L/B ratio ranged from 2.45 (IR79156A/AP-18) to 5.15 (IR79156A/R ) with an overall mean of Among the crosses with line IR58025A, IR58025A/ R (4.69) recorded the highest brown rice L/B ratio followed by IR58025A/R (4.69). Among the crosses with IR79156A, IR79156A/ R (5.15) showed highest mean followed by IR79156A/R (4.28) while the crosses with line CRMS31A, CRMS31A/R (5.13) recorded highest mean followed by CRMS31A/R (4.46). Among the entire cross combinations, three cross combinations viz., IR58025A/R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for brown rice L/B ratio. 10. Kernel length (mm) Among hybrids, kernel length ranged from 4.20 mm (IR58025A/R ) to 6.20 mm (CRMS31A/R ) with an overall mean of 5.34 mm. Among the crosses with line IR58025A, IR58025A/ R (6.13mm) recorded the highest kernel length followed by IR58025A/R (5.43 mm). Among the crosses with IR79156A, IR79156A/ R and R (6.03 mm) showed highest mean followed by R79156A/R (5.60 mm) while the crosses with line CRMS31A, CRMS31A/R and recorded highest mean followed by CRMS31A/ R (6.10 mm). Among the entire cross combinations, following cross combinations viz.,ir58025a/ R , IR79156A/ R and IR79156A/ R and CRMS31A/R were identified as good performing hybrids for kernel length.

95 Kernel breadth (mm) Among hybrids, kernel breadth ranged from 1.30 mm (IR58025A/R ) to 2.21 mm (IR58025A/ R ) with an overall mean of 1.79 mm. Among the crosses with line IR58025A, IR58025A/ R (1.79 mm) recorded the highest kernel breadth followed by IR58025A/ R (2.09mm). Among the crosses with IR79156A, IR79156A/ R (2.13 mm) showed highest mean followed by IR79156A/Reg-1649 (1.97 mm) while the crosses with line CRMS31A, CRMS31A/R , (2.08 mm) recorded highest mean followed by CRMS31A/AP-16 (2.00 mm). Among the entire cross combinations, following cross combinations viz., IR58025A/ R , IR79156A/ R , CRMS31A/ R , were identified as good performing hybrids for kernel breadth. 12. Kernel L/B ratio Among hybrids, brown rice L/B ratio ranged from 2.33 (IR58025A/AP-18) to 4.90 (CRMS31A/ R ) with an overall mean of Among the crosses with line IR58025A, IR58025A/ R (4.72) recorded the highest kernel L/B ratio followed by IR58025A/ R (3.98). Among the crosses with IR79156A, IR79156A/ R (4.42) showed highest mean followed by IR79156A/ R (4) while the crosses with line CRMS31A, CRMS31A/R (4.90) recorded highest mean followed by CRMS32A/ R (3.93). Among the entire cross combinations, following cross combinations viz., IR58025A / R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for brown rice L/B ratio. 13. Cooked Rice length (mm) Among hybrids, cooked rice length ranged from 7.03 mm (IR58025A/R ) to 9.47 mm (IR58025A/R ) with an overall mean of 8.11 mm.

96 80 Among the crosses with line IR58025A, IR58025A/ R (8.11 mm) recorded the highest cooked rice length followed by IR58025A/R (8.30 mm). Among the crosses with IR79156A, IR79156A/ R (9.09 mm) showed highest mean followed by IR79156A/ R (9.55 mm) while the crosses with line CRMS31A, CRMS31A/ (8.57 mm) recorded highest mean followed by CRMS31A/AP-18. Among the entire cross combinations, following cross combinations viz., IR58025A/R , IR79156A/R and CRMS31A/R were identified as good performing hybrids for cooked rice length. 14. Cooked Rice breadth (mm) Among hybrids, cooked rice breadth ranged from 2.33 mm (IR58025A/R , IR79156A/R ) to 3.60 mm (IR58025A/Reg- 1649,IR79156A/R ) with an overall mean of 2.96 mm. Among the crosses with line IR58025A, IR58025A/Reg-1649, (3.60 mm) recorded the highest cooked rice breadth followed by IR58025A/AP-16 (3.53 mm). Among the crosses with IR79156A, IR79156A/R (3.60 mm) showed highest mean followed by IR79156A/Reg-1649 (3.40 mm), while the crosses with line CRMS31A, CRMS31A/R (3.40mm) recorded highest mean followed by CRMS31A/AP-18 (3.33 mm). Among the entire cross combinations, following cross combinations viz., IR58025A/Reg-1649, IR58025A/R , CRMS31A/R were identified as good performing hybrids for cooked rice breadth. 15. Cooked Rice L/B ratio Among hybrids, cooked rice L/B ratio ranged from 2.09 (IR58025A/R ) to 3.93 (IR79156A/R ) with an overall mean of Among the crosses with line IR58025A, IR58025A/ R (3.57) recorded the highest cooked rice L/B ratio followed by IR58025A/R (2.90).

97 81 Among the crosses with IR79156A, IR79156A/ R (3.93) showed highest mean followed by IR79156A/ R (3.22) while the crosses with line CRMS31A, CRMS31A/ R (3.60) recorded highest mean followed by CRMS31A/R (3.43). Among the entire cross combinations, following cross combinations viz., IR58025A/ R , IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for cooked rice L/B ratio. 16. Elongation ratio Among hybrids, elongation ratio ranged from 1.27 (IR58025A/ R ) to 1.97 (IR79156A/ R ) with an overall mean of Among the crosses with line IR58025A, IR58025A/AP-18 (1.67) recorded the highest elongation ratio followed by IR58025A/ R (1.63) and IR58025A/ R (1.63). Among the crosses with IR79156A, IR79156A/ R (1.97) showed highest mean followed by IR79156A/ R (1.60) while the crosses with line CRMS31A, CRMS31A/ R (1.87) recorded highest mean followed by CRMS31A/R , CRMS31A/R , CRMS31A/AP-18 (1.57). Among the entire cross combinations, following cross combinations viz., IR58025A/AP-18, IR79156A/ R and CRMS31A/ R were identified as good performing hybrids for elongation ratio. 17. Alkali Spreading Value (ASV ) Among hybrids, the scoring of alkali spreading value and gelatinization temperature ranged from 2.33 IR58025A/R to 7 (most of the hybrids) with an overall scoring mean of Among the crosses with line IR58025A, IR58025A/ R (7) recorded the highest alkali spreading value and gelatinization temperature score followed by IR58025A/ R , IR58025A/R and other (6.67). Among the crosses with IR79156A, IR79156A/ R (7) showed highest score mean followed by all remain hybrids (6) while the crosses with

98 82 line CRMS31A, CRMS31A/ and most of the hybrid (7) recorded highest score mean followed by all remain hybrid (6). Among the entire cross combinations, following cross combinations viz., IR58025A/ R , IR79156A/ R , and most of the hybrid were identified as good performing hybrids for Alkali spreading value and gelatinization temperature. The good quality rice grains have Intermediate (4-5) alkali spreading value and gelatinization temperature. 4.2 Identification of Restorer and Maintainer Lines The specific genotypes which produce higher fertile (above 75% spikelet fertility and above 80% pollen fertility) progeny after the crossing with the CMS lines can be used as male parent and are called potential restorers. Similarly those specific genotypes which produce completely male sterile progeny (0-0.1 spikelet fertility % and 0-1 % pollen fertility % ) after crossing with CMS line, can be converted into female parent (CMS line) are called maintainers. Partial restorers are not useful for developing the hybrids. Thus potential restorer can be utilized in further hybrid rice breeding programme to develop situation specific hybrids.

99 83 Table 4.2 List of Identified Restorers and Maintainers CMS LINE Potential Maintainer (pollen fertility % 0 to 1 and spikelet fertility % ) Partial Maintainer (pollen fertility % 1.1 to 50 and spikelet fertility % 0.1 to 50) Partial restorer (pollen fertility%50.1 to 80 and spikelet fertility %50.1 to 75) Potential Restorer (pollen fertility % >80 and spikelet fertility % >75) IR 58025A --- R R , R , AP-16, AP-18, Reg-1649 R , R IR 79156A --- R , R , R , R , R , AP-16, AP-18, Reg CRMS31A --- R , R , R , AP-16, AP-18, Reg-1649 R , R

100 84 Frequency of Restorers and Maintainers (Based on pollen and spikelet fertility) Classification based on S.No. CMS LINE POLLEN FERTILITY SPIKELET FERTILITY R % PR % PM % M % R % PR % PM % M % 1 IR58025 A IR79156 A CRMS 31A TOTAL

101 Fertility % PFR/SFR PFPR/SFPR PFPM/SFPM PFM/SFM Fertility classes POLLEN FERTILITY SPIKLET FERTILITY