Open Access Journal of Plant and Pest Science (ISSN: 2204-0021) Vol. 1, Issue.1: 54-58 (August 2014) journals.sfu.ca/jpps/index.php/jpps/index Original Research Article Received: 24 Jul 2014, Accepted: 20 Aug 2014, Published: 25 Aug 2014 Identification of Effective Restorers and Maintainers of Wild Abortive (WA) Cytoplasmic Male Sterile Lines in Rice (Oryza sativa L.): A Review Dar SH*, Ahangar MA, Najeeb S, Saleem N and Ahmad N Author Info Mountain Research Centre for Field Crops, KhudwaniSKUAST-Kashmir, 190025 India. *Corresponding author s email: dar.sajad@rediffmail.com Key Words CMS, Maintainers, Restorers line, Rice, WA Abstract A review of the previous works was done for identification of potential restorers and maintainers which form an integral part of cytoplasmic-genic male sterile (CMS) based hybrid rice programme. Sufficient works have been done by the researcher worldwide in this regard and the researchers have classified potential restorers and maintainers based on their pollen and spikelet fertility per cent. From almost all these studies it was found that the ratio of restorers was lower than partial restorers, maintainers and partial maintainers.the presence of restorers and maintainers among elite genotypes reveals the possibility of developing rice hybrids. Introduction: For an efficient hybrid rice breeding programme, identification of restorers, maintainers and evaluation of parental lines and conversion of promising maintainer lines in to CMS lines forms an integral part of hybrid rice technology. As such, it becomes important to identify the potential restorers and maintainers from the existing germplasm. Yuan and Fu (1995) detailed all the stages that should be followed to obtain male-sterile lines, restorers and maintainers. Hybrid rice would then be produced through a so-called three-line system, where one line would have the genetic cytoplasmic male sterility; the second line would be responsible for maintaining the sterility and a third one would be used as the matching parent for the hybrid with the responsibility of restoring the fertility. Cytoplasmic male sterility and the fertility restoration system have been primarily used to develop heterotic rice hybrids in and outside China (Lin and Yuan, 1980 and Virmani et al., 2003). To stimulate rice heterosis in a controlled environment, a male sterile line is required. Cytoplasmic male sterility (CMS, or threeline) system requires a cytoplasmic male sterile or A line; a maintainer or B line to produce offspring with male sterility, but with normal fertility itself and a restorer or R line to produce F1 seeds and to undergo the F1 heterosis. Male sterile line (A line): The cytoplasmic male sterility trait is controlled both cytoplasm and nucleus; this line is used as female in hybrid seed production. Maintainer line (B line): This line is used as a pollinator to maintain the male sterility. The maintainer line has viable pollen grains and sets normal seed. Restorer line (R line): Any rice cultivar that restores fertility in the F1 when it is crossed to a CMS line. In this article we are taking a review of work done all over the world for assessing the restorer and maintainer lines, so that we may have through knowledge regarding the research in this direction and it will ease our work on this aspect in future. Cite this article: Dar SH, Ahangar MA, Najeeb S, Saleem N and Ahmad N (2014) Identification of Effective Restorers and Maintainers of Wild Abortive (WA) Cytoplasmic Male Sterile Lines in Rice (Oryza sativa L.): A Review, Journal of Plant and Pest Science, 1 (1): 54-58 54
Fertility restoration: Forty cultivars as pollen parents were crossed with the cytoplasmically male-sterile lines V20A, V97A, Pankhari 203A, IR46826A, IR54752A and IR54753A (Tomar et al., 1990). In addition, 23 cultivars were crossed with V20A and V97A. Pollen of each CMS line was tested for sterility before crossing. Cultivars were classified as effective restorers (>80 per cent spikelet fertility), weak or partial restorers (40-79 per cent), weak or partial maintainers (1-39 per cent) and effective maintainers (<1 per cent). Spikelet fertility was observed in F 1 progenies of IR46828A and IR54752A crossed with single plant selections of elite cultivars, indicating that these last were partial to full restorers. Joshi et al. (2003) categorized the test lines as restorers, partial restorers, maintainers and partial maintainers on the basis of pollen sterility and spikelet fertility and reported that five restorers, three partial restorers, two partial maintainers and four maintainers so identified can be used to develop the hybrid seed while maintainers to maintain and/or to develop new CMS lines, because these are locally adapted cultivars. Bisne and Motiramoni (2005) evaluated four CMS lines and eight testers in the line tester analysis with 32 hybrids. A very low magnitude of pollen and spikelet fertility was observed for hybrids. Hybrids showed more than 70 per cent spikelet fertility and 80 per cent pollen fertility. The variations in behavior of fertility restoration indicate that either the fertilityrestoring genes are different or that their penitrance and expressivity varied with the genotypes of the parents or the modifiers of female background. Seven cytoplasmicgenic male sterile (CMS) lines of rice having wild abortive (WA) cytoplasmic male sterility source and one having Oryza perennis CMS source were crossed with 34 entries to assess their maintainer/restorer behavior. Most of the genotypes expressed differential fertility reactions when crossed with CMS lines having WA cytoplasm and all test entries produced sterile hybrids when crossed with CMS line having O. perennis source. Among the genotypes tested, Annapoorna, Kanchana, IR 36, Mattatriveni and Aiswarya are recognized as effective restorers for WA cytoplasmic male sterile lines. Jyothy produced completely sterile hybrids with all CMS lines. Aruna, Pavizham and Ptb 10 were maintainers for five CMS lines. (Rosamma and Vijayakumar, 2005) Sidharthan et al. (2007) conducted an experiment of various rice CMS lines and their maintainer lines for stability of pollen and spikelet fertility. A total of thirty five CMS lines and twenty four maintainer lines of divergent origin were included in the study. About 16 lines were found to be completely pollen sterile while others showed spikelet fertility ranging from 0.50 per cent to 6.50 per cent. The CMS lines DRR 6A, DRR 7A, PMS 17A, COMS 14A, COMS 15A, RTN 2A, RTN 3A, RTN 6A, RTN 18A, IR68888A were found promising for the character of pollen sterility, panicle exertion, stigma exertion and natural out crossing. These CMS lines may be further studied and utilized for three line hybrids Rice production technology. Saber et al. (2007) evaluated one hundred and nine rice genotypes for their status in hybrid rice parental gene pool. Twenty restorers and 26 maintainers were identified for use in hybrid rice research programme. From 113 test hybrids evaluated 20 restorers, 30 partial restorers, 37 partial maintainers and 26 maintainers were categorized on the basis of pollen and spikelet sterility/fertility. The frequency of restorers, partial maintainers and maintainers were 17, 26, 32 and 23 per cent, respectively. Nine basmati and 11 coarse lines were identified as restorers from the tested genotypes. In addition, nine best heterotic combinations were also identified from the testcrosses on the basis of filled grains panicle -1 and spikelet fertility. It was revealed that seven identified heterotic hybrid combinations had more than 80 per cent spikelet fertility and acceptable maturity days and plant height. Sarial and Singh (2008) test crossed twenty-seven improved aromatic lines of germplasm and 18 non-aromatic disease-resistant genotypes of rice with four cytoplasmic male-sterile lines (IR 58025A, IR 62829A, PMS 3A and PMS 10A). Thirteen aromatic and 10 non-aromatic genotypes were selected based on pollen fertility, and crosses were repeated to confirm sterility-maintaining and fertility-restoring ability. Genotypes were categorized as effective restorers 55 Journal of Plant and Pest Science
(> 80 per cent spikelet fertility), partial restorers (21-79 per cent spikelet fertility) and maintainers (< 1 per cent spikelet fertility). The effective basmati restorers identified were Basmati 385, Chandan, P1031-8-5-1, HKR 241- IET-12020, SAF Khalsa 7 and Karnal Local. The basmati maintainers identified were Basmati 370, Pusa basmati 1, P615-K-167-13 and P1173-4-1. The frequency of restorers obtained was higher for the non-aromatic than the aromatic basmati type. The performance of restorers varied with cytoplasmic male-sterile (CMS) line, location and season of testing. The differential ability to restore fertility in the CMS lines that have the wild abortive (WA) cytosterile system could result from different nuclear backgrounds of the CMS lines. These restorers and maintainers possess acceptable grain dimensions, a desirable degree of aroma, volume expansion through linear kernel elongation and cooking quality characteristics of basmati rice. Evaluation of 220 F1 hybrids along with 145 genotypes and 10 stable CMS lines using line x tester mating design was carried out by Ingale et al. (2008). They categorized genotypes as effective restorers (>80 per cent spikelet fertility), partial restorers (20 to 79 per cent spikelet fertility), partial maintainers (10-19 per cent spikelet fertility) and maintainers (<10 per cent 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 per cent) followed by COMS-9A (60 per cent), IR- 62275A (43 per cent), PMS-11A (26 per cent) and IR- 68892A (23 per cent). The maximum effective restorers were observed for IR-68899A (55 per cent) followed by IR-68275A (36 per cent), IR-58025A (34 per cent) and IR-68885A (33 per cent). The average proportion of maintainers, partial maintainers/partial restorers and effective restorers were 35:47:18 per cent, respectively in these crosses. Akther, et al. (2007) evaluated two hundred thirty nine (239) rice genotypes for their status in hybrid rice gene pool. From these 239 test crosses twelve (12) restorers and 16 maintainers (8 Basmati and 385. Filled grains panicle-1 of the hybrids ranged from 101.2 to 145.2 as compared to the check variety (84.6). Zhou et al., (2010) conducted a diallel cross experiment of 4 rice (Oryza sativa L.) female and 6 male varieties to study the genetic effects and their interaction with salt-stress condition of 7 agronomic traits in normal and salt-stressed planting conditions. The panicle length (PL), effective number of panicles plant -1 (ENP), plumped number of grains panicle -1 (PNG), total number of grains panicle -1 (TNG), 1000-grain weight (W), seed setting ratio (SSR) and grain weight plant -1 (PGW), were investigated. A genetic model including additive effect, dominance effect and their interaction effects with environment (ADE) was employed for analysis of data. It was observed that significant (p<0.05) additive effects, dominance effects, additive x environment interaction effects and dominance environment interaction effects exist for most of the agronomic traits of rice. Eight CMS lines were crossed as 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 expressed as restorers 52 as PR, 28 as maintainers. Ten tester s viz., IR 62037, IR 72865, IR 68427, MDU5, TP1021, RR363-1, RR 347-1, RR 286-1, ACK 99017 and ASD06-08 were identified as restorers for all the eight CMS lines (Umadevi, et al. 2010). Study of inheritance of fertility restoration of WA type CMS in rice, (Oryza sativa L.) by utilizing IR58025A, IR62829A and IR68899A CMS lines and three restorers viz., Amol-2, IR50 and Poya. The F 1 s showed pollen and spikelet fertility similar to the restorer parents, indicating that restoration ability were dominant and the cytoplasmic-genetic sterility system of CMS lines were saprophytic in nature. Evaluation of fertility in F 2 populations and testcross progenies (BC1) revealed that fertility restoration in Amol-2 and IR50 were controlled by two major dominant genes whereas, it was controlled by one dominant gene in Poya. Segregation for spikelet fertility in F 2 and backcross generation conformed to the results on pollen fertility. Analysis of line x tester indicated pre-dominance of non-additive genetic variance. It suggested greater importance of non-additive gene action Journal of Plant and Pest Science 56
in pollen and spikelet fertility expression and indicated very good prospect for the exploitation of non-additive genetic variation for pollen and spikelet fertility through hybrid breeding (Bagheri and Babaeian-Jelodar, 2011). A study for the identification of restorer and maintainer lines for Tarai regions of Uttar Pradesh and Uttarakhand was conducted by Khan et al. (2012). Field experiment, comprised of hundred rice hybrids derived from Two CMS lines (IR 58025A and Pusa 6A) and fifty testers (male) following L x T mating design. Genotypes were categorized as Restorers (> 80 per cent Spikelet fertility), Partial restorers (20 to 79 per cent Spikelet fertility), Weak maintainers (10-20 per cent Spikelet fertility) and Maintainers (< 10 per cent Spikelet fertility). Out of 50 male lines 19 lines behaved like restorer and 3 lines behaved like maintainer with both of CMS (IR58025A and Pusa 6A) line. Banumathy et al. (2013) Five cytoplasmic male sterile (CMS) lines with Wild Abortive (WA) CMS source and one CMS line having Oryza perennis cytoplasm were crossed with 20 rice genotypes to assess their restorer/maintainer behavior. All the 20 F 1 s with IR 66707A line having O. perennis cytoplasm produced only sterile hybrids. Most of the genotypes expressed differential fertility reactions when crossed with CMS lines having WA cytoplasm. The genotypes, IR 10198-66-2R, IR 65515-47-21-19, TNAU 94241 and TNAU 841434 were identified as effective restorers while ADT 43, ASD 19, CB 97083 and CO (R) 47 produced completely sterile hybrids with CMS lines carrying WA cytoplasm. Ten best heterotic combinations were identified based on economic traits. Veeresha (2013) Fifty three (53) rice genotypes were crossed with two CMS lines viz., IR58025A and IR68888A. 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. The SSR marker RM6100 has been used to confirm the presence of fertility restorer gene Rf 4 in the germplasm lines. Analysis of 31 test crosses by (Jakkrit et al., 2014) revealed 6 restorers and 9 maintainers based on pollen fertility. The estimation of heterosis to select superior genotypes was conducted on 12 hybrids resulting from crosses between 6 restorers and 2 male sterile lines. The results show that two hybrids had a high heterobeltiosis and standard heterosis, with yields of 7940 and 6810 kg/ha, respectively. The inheritance of fertility-restorer genes of F2 populations in crosses IR80151A/CH1 and IR80151A/CH4 was evaluated at heading to flowering stage based on pollen fertility and seed setting rate (SSR). The segregation ratio of pollen fertility was 15:1 (fertile: sterile), representing two nuclear independent dominant genes controlling the trait with saprophytic abortive fertility. The SSR, however, could not be used to study fertility-restorer genes, as it is influenced by physiological andenvironmental factors. Conclusion The presence of restorers and maintainers among elite genotypes reveals the possibility of developing rice hybrids for temperate agroecologies and more particularly for Kashmir valley. Also new CMS lines in diverse genetic backgrounds can be developed in locally adapted germplasm that is prerequisite for hybrid rice breeding. Restorer genes found in exotic genotypes can be transferred to elite high yielding and desirable genotypes through appropriate backcross breeding programme to develop new restorer lines. References Akhter M, Zahid MA, Sabir and Ahmad M (2007) Identification of restorers and maintainers for the development of rice hybrids, Journal of Animal and Plant Science, 18(1). Bagheri N and Jelodar NB (2011) Genetics and combining ability of fertility restoration of wild abortive' cytoplasmic male sterility in rice, African Journal of Biotechnology, 10(46): 9314-9321. Banumathy S, Thiyagarajan K and Manonmani S (2013) Evaluation of rice genotypes for fertility restoration against WA and O. perennis cytoplasm based cytoplasmic male sterility, Indian Journal of Genetics and Plant Breeding, 73(2):199-202. Bisne R and Motiramani NK (2005) Identification of maintainers and restorers using WA source cytoplasmic male 57 Journal of Plant and Pest Science
sterile lines in rice (Oryza sativa L.), IRRN, 30(1). Ingale BV, Waghmode BD and Shodawadekar SS (2008) Identification of restorers and maintainers for different CMS lines of rice, Madras Agriculture Journal, 95: 266-277. Jakkrit S, Prapa S and Tanee S (2014) Heterosis and inheritance of fertility-restorer genes in rice, Science Asia, 40: 48 52. Joshi KB, Laxmi SP, Santa GBS and Sharma CR (2003) Evaluation of cultivars and land races of rice (Oryza sativa L.) for restoring and maintaining wild abortive cytoplasm, Himalayan Journal of Sciences12:170-178. Khan MA, Malik S, Singh S (2012) Identification of maintainers and restorers for development of potential rice (Oryza sativa L.) hybrids for tarai region. Vegetos: An International Journal of Plant Research, 25(1): 48-51. Lin SC and Yuan LP (1980) Hybrid rice breeding in China, in Innovative approaches to rice breeding, International Rice Research Institute, 35-51. Rosamma CA and Vijayakumar NK (2005) Maintainers and 38 restorers for CMS lines of rice, Journal of Tropical Agriculture, 43(1-2): 75-77. Sabar M, Akhter M, Faiz FA, Ali SS and Ahmad M (2007) Identification of restorers and maintainers for developing hybrid rice, Journal of Agricultural Research, 45(1): 440-447. Sarial AK and Singh VP (2008) Identification of restorers and maintainers for developing basmati and non-basmati hybrids in rice (Oryzasativa L.), Plant Breeding, 119(3): 243-247. Sidharthan B, Thiyagarajan K and Monomania S (2007) Cytoplasmic male sterile lines for hybrid rice production,journal of Applied Sciences Research,3(10): 935-937. Tomar JB and Virmani SS (1990) Identifying maintainers and restorers of CMS lines for hybrid rice breeding, International Rice Research Newsletter, 15(8): 5-6. Umadevi M, Veerabadhiran P, Manonmani S and Shanmugasundaram P (2010) Identification of potential maintainers and restorers using cytoplasmic male sterile lines in rice, Electronic Journal of Plant Breeding, 1(4): 948-952. Veeresha BA, Hanamaratti NG, Salimath PM and Chetti MB (2013) Identification of restorers and maintainers for development of rice hybrids,ioinfolet - A Quarterly Journal of Life Sciences10(2): 602-606 Virmani SS, Mao CX and Hardy B (2003) Hybrid rice for food security, poverty alleviation, and environmental protection, Proceedings of the 4th International Symposium on Hybrid Rice, Hanoi, Vietnam, International Rice Research Institute, 407. Yuan LP and Fu XQ (1995) Technology of hybrid rice production, Rome FAO,84. Zhou HK, Hayat Y, Fang LJ, Guo RF, He JM and Xu HM (2010) Analysis of genetic and genotype environment interaction effects for agronomic traits of rice (Oryza sativa L.) in salt tolerance, Pak. J. Bot., 42(5): 3239-3246.Research Article Journal of Plant and Pest Science 58