Indian J. Agric. Res., 42 (1) : 7-12, 2008 EFFECT OF POLLINATION TIME AND CROSSING RATIO ON SEED YIELD AND QUALITY OF BRINJAL HYBRID UNDER DHARWAD REGION OF KARNATAKA Shivashankaragouda B. Patil, M.N. Merwade, B.S. Vyakaranahal and V.K. Deshpande Department of Seed Science and Technology University of Agricultural Sciences, Dharwad - 580 005, India ABSTRACT The field experiment was conducted during kharif 2003 and 2004 at College of Agriculture, Dharwad. The results revealed that pollination at 9:00 am recorded significantly highest germination, root length, shoot length, vigour index and seedling dry weight followed by pollination at 11.00 am compared to 1:00 pm pollination time. Irrespective of the pollination time, 4:1 crossing ratio recorded significantly maximum germination percentage, root length, shoot length, vigour index and seedling dry weight as compared to the 10:1 crossing ratio. INTRODUCTION Brinjal (Solanum melongena L.) popularly known as egg plant belongs to family Solanaceae and India is its center of origin and diversity (Vavilov, 1931 and Bahaduri, 1951). It is a popular and principle fruit vegetable grown in India and other parts of tropical and subtropical world but in temperate regions, it is grown mainly during warm season (Rai et al., 1995). Apart from India, the other major brinjal growing countries are China, Turkey, Japan, Italy, Indonesia, Iraq, Syria, Spain and Phillippines. Across the globe, it is grown annually on 1.50 million ha area contributing 25.07 million tonnes with 16.67 tonnes per ha as productivity (Anonymous, 2004). In brinjal, F 1 hybrid seed set and yield are influenced by several factors like time of emasculation and pollination and crossing ratio besides use of improved seed production techniques. The most productive and desirable hybrid seed can be obtained from the female parent when there is a perfect coincidence of stigma receptivity with pollen viability of male parent. Since brinjal is mainly a self pollinated crop, pollination is done usually on the day of flower opening itself and can be continued till noon hours, though peak anthesis is seen at 8:30 to 10:30 am. But success rate of pollination varies from 50 to 70 per cent in brinjal hybrid seed production. Early pollination with viable pollen may lead to poor seed setting due to non receptivity of stigma and similar is the case if flowers are pollinated very late, because of drying of stigma or loss of pollen viability. In addition to this, the amount of F 1 hybrid seed is also decided by the quantity of the pollens pollinating on the receptive stigma of the female parent. In case, if more pollens have pollinated the stigma, there may be more chances of poor seed setting due to competition between germinating pollens. Similar is the case with pollination with inadequate viable pollens. The quantity of pollens depositing on stigma can be manipulated by adjusting the crossing ratio of female to male flower. Therefore, time of pollination and ratio between female : male flower crossing is to be optimized to get higher seed set and yield in hybrid brinjal. However, research work pertaining to time of pollination and crossing ratio between male and female flowers is very meagre and in conclusive. Hence, this investigation was initiated to find out suitable time of pollination and crossing ratio of female to male flower on hybrid seed production, seed yield and quality of brinjal hybrid, ArkaNavaneet. MATERIAL AND METHODS The seed material of female parent, IIHR 22-1 and male parent, Supreme of brinjal
8 INDIAN JOURNAL OF AGRICULTURAL RESEARCH hybrid cultivar ArkaNavaneet was obtained from the Indian Institute of Horticultural Research, Bangalore. Prior to sowing, the seeds of both parents were treated with bavistin at the rate of two g per kg of seeds for getting vigourous and healthy seedlings. The treated seeds of male and female parents were sown in the raised beds separately male parent was sown 10 days before the female parent sowing. It was watered alternately and plant protection measures were taken regularly as required. The bed was kept weed free with manual weeding during the nursery period. Uniform sized healthy 25 days old male and female seedlings were transplanted in two adjacent parental blocks of the crossing field. One seedling per hill was planted at inter and intra-spacing of 75 and 75 cm for female and 60 and 60 cm for male parents, respectively. A distance of five meter was maintained between the female and male parental blocks. A plot size of 4.5 x 4.5 m and 3.6 x 3.6 m was maintained for female and male parents respectively. This experiment was conducted in brinjal hybrid Cv. ArkaNavneet during kharif 2003 and 2004 years in randomised block design in factorial concept with three replications. It consisted of two factors. The time of pollination as one factor viz., pollination between 9.00 to 11.00 am ( ), 11.00 am to 1.00 pm ( ) and 1.00 to 3.00 pm ( ) and female to male flower crossing ratio as another factor viz., 2:1 ( ), 4:1 ( ), 6:1 ( ), 8:1 ( ) and 10:1 ( ). The hermophrodite flowers of female parent, IIHR 22-1 were emasculated in the previous evening between 2.0 to 6.0 pm. Only the floral buds likely to open on next day morning hours were only emasculated by using the forcep, needle, scalpel, etc. Since female parent was indeterminant in growth habit, the emasculation work was restricted only to first 30 days from start of flowering period wherein flowering was at its peak. The fresh pollens extracted from male parental flowers were filled up in the plastic rings specially designed for easy pollination. The stigma of previously emasculated female buds were gently dipped in pollen mass of plastic ring borne on left hand forefinger. At the start of blooming period, fully opened flowers were plucked from the male parental block and were collected in polythene bag in early morning hours of the crossing day. The pollen separated from anthers were filtered through muslin cloth into another cup. The extracted pollens were then transferred to plastic vials by using camel hair brush. The plastic vials were kept in a cool place for over night period under ambient conditions and also in a refrigerator until required for crossing. At the end of the experiment some biometric observations were recoded from each treatment randomly. The analysis of variance and interpretation of data were done as per procedure given by Panse and Sukhatme (1967) and Gomez and Gomez (1984). Levels of significance used in F test was P=0.05. Critical difference (CD) values were calculated only wherever the F test was found significant. Germination test was conducted as per the procedure of ISTA Rules (Anonymous, 1996). The data on germination percentage was converted into arcsine transformation and used for statistical analysis. RESULTS AND DISCUSSION From the pooled data, it was revealed that the seed yield (56.43 g) per plant was noticed in pollination at 9:00 to 11:00 am followed by pollination at 11:00 am to 1:00 pm (38.34 g). It was significantly the lowest (23.57 g) in pollination at 1:00 to 3:00 pm ( ). The significant increase in seed yield per plant was recorded with 9:00 to 11:00 am pollination time may be due to its higher fruit set percentage, fruit weight and number of seeds per fruit, as is evident from this study. These results might also be related to the prevalence of higher stigma receptivity and peak pollen viability during 9:00 to 11:00 am period in view of congenial environmental conditions. Obviously it might have significant increase in
seed yield per plant and its components at 9:00 to 11:00 am pollination compared to other pollination timings. Significantly higher and lower germination percentage was noticed at 9:00 to 11:00 am pollination (83.23) and 1:00 to 3:00 pm pollination (70.21) which differed significantly from 11 :00 am to 1:00 pm pollination (77.45). In pooled analysis, shoot length was significantly more in pollination at 9:00 to 11:00 am (8.34 cm) which was at par with pollination at 11:00 am to 1:00 pm (8.10 cm) ( ). It was markedly less (7.31 cm) with pollination at 1:00 to 3:00 pm irrespective of number of female flowers pollinated per male. The pooled results revealed significant differences for seedling vigour index with respect to pollination time only whereas number of female flowers crossed per male and their interaction effect were found to be nonsignificant. In pooled analysis, significantly the highest and lowest seedling vigour index was recorded in (1406) and (1091), respectively but these differed significantly with (1240). Pollination at 9:00 am to 1:00 pm ( ) recorded significantly higher seedling dry weight (15.19 mg) which was at par with pollination at 11:00 am to 1:00 pm (14.43 mg), but it was significantly lower (12.72 mg) at 1.00 to 3:00 pm pollination over the number of female flowers pollinated per male (Table 1 and 2). The significant increase in seed quality parameters recorded at 9:00 am pollination may be due to higher fruit weight, number of seeds per fruit and seed weight as is evident in this study and these factors might have produced more number of heavier and bolder seeds contributing to better seed quality in the 9:00 to 11:00 am pollination time. On the other hand, seed quality traits were lower with 1:00 to 3:00 pm pollination and it can be attributed to Vol. 42, No. 1, 2008 immature and thinner seeds obtained from the delayed pollination. These results are corroborative with those of Petrova et al. (1981) in brinjal Yogeesha et al. (1999) and Jolli (2004) in tomato. Seed yield per plant was significantly maximum (54.32 g) in ( ) four female flowers pollinated per male flower. It was followed by (41.95 g) which was on par with (38.00 g). Whereas, significantly minimum seed yield (30.39 g) per plant was noticed in ten female flowers per male ( ) irrespective of pollination time. Four female flowers pollinated per male flower ( ) recorded significantly maximum seedling dry weight (15.10 mg) as compared to other treatments irrespective of pollination time. Whereas, it was significantly minimum (13.44 mg) in which was statistically at par with, and (Table 1 and 2). The crossing ratio 4:2 ( ) recorded significantly maximum root length (8.51 cm) as compared to other treatments irrespective of pollination time and it was at par with six female flowers pollinated per male (8.27 cm). Significantly minimum root length (7.95 cm) was seen in two female flowers per male flower ( ). Number of female flowers crossed per male flower recorded numerically more vigour index (1321) in four female flowers crossed per male ( ) followed by (1276) and (1270) and it was numerically less (1203) in ten female flower crossed per male ( ) treatment. These results are in agreement with the findings of Petrova et al. (1981), Chen (2003) in brinjal, Yogeesha et al. (1999) and Jolli (2004) in tomato and Padda and Singh (1971) in capsicum hybrid seed production. Marked differences due to crossing ratios were recorded only for root length and seedling dry weight, while other quality parameters were found non-significant over the pollination time. However, germination 9
10 INDIAN JOURNAL OF AGRICULTURAL RESEARCH TABLE 1: Effect of pollination behaviour and crossing ratios on seed yield, germination percentage and root length in brinjal hybrid seed production Treatment Seed yield (g) per plant Germination (%) Root length (cm) 2003 2004 Mean 2003 2004 Mean 2003 2004 Mean Pollination time (T) 62.08 50.78 56.43 83.90 (66.35)* 82.57 (65.42) 83.23 (65.80) 8.65 8.48 8.56 42.78 33.91 38.34 77.62 (61.75) 77.30 (61.55) 77.46 (61.61) 8.39 8.04 8.22 22.57 19.57 23.57 69.05 (56.23) 71.37 (57.61) 70.21 (56.91) 7.60 7.85 7.73 S.Em± 2.98 2.60 1.98 1.99 0.68 1.05 0.08 0.13 0.08 CD @ 5% 8.63 7.53 5.73 5.76 1.96 3.04 0.23 0.38 0.23 Crossing ratio 43.98 32.01 38.00 77.17 (61.48) 77.74 (61.82) 77.45 (61.61) 8.19 7.70 7.95 58.93 44.70 54.32 77.93 (61.96) 78.52 (62.38) 78.23 (62.17) 8.49 8.53 8.51 43.72 40.18 41.95 77.32 (61.55) 77.24 (61.48) 77.28 (61.55) 8.33 8.20 8.27 38.89 26.29 32.59 76.77 (61.14) 76.45 (60.94) 76.61 (61.07) 8.10 8.16 8.13 35.19 25.59 30.39 75.10 (60.07) 75.45 (60.33) 75.28 (60.13) 7.95 8.03 7.99 S.Em± 3.85 3.36 2.55 2.57 0.88 1.36 0.11 0.17 0.10 CD @ 5% 11.15 9.73 7.38 NS NS NS 0.32 0.49 0.29 Interactions (TxP) 66.95 43.92 55.43 81.56 (64.52)* 80.19 (63.51) 80.87 (64.01) 8.23 7.98 8.10 88.28 75.20 81.74 88.62 (70.27) 85.24 (67.37) 86.93 (68.79) 8.89 8.71 8.80 59.75 67.93 63.84 84.24 (65.58) 83.19 (69.91) 83.71 (66.19) 8.785 8.50 8.62 55.09 34.89 44.89 83.84 (66.27) 83.01 (69.73) 83.42 (65.96) 8.69 8.57 8.63 40.34 31.97 36.15 81.27 (64.30) 81.23 (64.30) 81.25 (64.38) 8.71 8.64 8.67 44.38 32.44 38.41 80.34 (63.65) 80.01 (64.43) 80.17 (63.58) 8.49 7.00 7.74 49.62 44.44 47.03 78.14 (62.10) 78.21 (62.17) 78.17 (62.17) 8.66 8.69 8.67 42.38 34.75 38.79 77.29 (61.48) 77.07 (61.41) 77.18 (61.48) 8.62 8.44 8.53 34.73 27.03 30.88 76.45 (60.94) 76.24 (60.80) 76.34 (60.87) 8.20 8.11 8.15 42.34 30.90 36.63 75.91 (63.36) 75.00 (60.00) 75.45 (60.27) 8.00 8.00 8.00 20.63 19.67 20.15 69.62 (56.54) 73.03 (58.69) 71.32 (57.61) 7.86 8.13 7.99 28.90 29.47 34.18 67.04 (54.94) 72.13 (58.12) 69.58 (56.54) 7.92 8.21 8.06 28.58 17.86 23.22 70.43 (56.98) 71.46 (57.67) 70.94 (56.35) 7.64 7.67 7.65 26.85 16.97 25.91 70.03 (56.79) 70.10 (56.85) 70.06 (56.85) 7.43 7.81 7.62 22.89 13.89 18.31 68.13 (55.61) 70.14 (56.85) 69.13 (56.23) 7.16 7.46 7.31 S.Em± 6.67 5.82 4.43 4.46 1.53 2.35 0.19 0.30 0.17 CD @ 5% NS 15.18 NS NS NS NS NS NS NS NS - Non significant; * Figures in the parenthesis indicates arcsine transformed values; - Pollination at 9.00 to 11:00 am; - Pollination at 11.00 am to 1:00 pm; - Pollination at 1.00 to 3:00 pm; - Two female flowers per male; - Four female flowers per male; - Six female flowers per male; - Eight female flowers per male; - Ten female flowers per male.
Vol. 42, No. 1, 2008 11 TABLE 2: Effect of pollination behaviour and crossing ratio on shoot length, seedling vigour index and seedling dry weight in brinjal hybrid seed production Treatments Shoot length (cm) Seedling vigour index Seedling dry weight (mg) 2003 2004 Mean 2003 2004 Mean 2003 2004 Mean Pollination time (T) 8.43 8.26 8.34 1430 1382 1406 16.06 14.29 15.19 8.08 7.94 8.01 1314 1266 1290 15.76 13.09 14.43 7.36 7.26 7.31 1113 1069 1091 14.00 11.43 12.72 S.Em± 0.16 0.13 0.10 36.04 38.91 26.52 0.34 0.37 0.25 CD @ 5% 0.46 0.38 0.29 104.28 112.71 76.82 0.99 1.07 0.74 Crossing ratio 8.03 7.97 8.00 1290 1250 1270 14.83 13.06 13.94 8.20 8.04 8.12 1355 1287 1321 16.39 13.81 15.10 7.99 7.84 7.92 1306 1246 1276 14.67 12.78 13.72 7.83 7.62 7.72 1260 1225 1242 15.35 13.33 14.34 7.74 7.64 7.69 1218 1189 1203 15.19 11.70 13.44 S.Em± 0.20 0.17 0.13 46.53 50.24 34.24 0.45 0.48 0.33 CD @ 5% NS NS NS NS NS NS 1.30 1.39 0.96 Interactions (TxP) 8.23 8.06 8.14 1313 1343 8.14 14.17 13.87 14.02 8.62 8.38 8.50 1563 1291 8.50 17.86 15.91 16.89 8.45 8.24 8.34 1450 1291 8.34 16.74 14.90 15.82 8.46 8.31 8.38 1436 1217 8.38 15.61 14.19 14.90 8.39 8.33 8.36 1390 1188 8.36 16.05 12.60 14.32 8.32 8.21 8.27 1397 1343 8.27 16.28 13.14 14.71 8.35 8.25 8.30 1335 1291 8.30 17.19 13.94 15.56 8.18 8.11 8.14 1350 1291 8.14 14.51 12.22 13.37 7.89 7.47 7.68 1264 1217 7.68 15.36 13.81 14.59 7.69 7.66 7.68 1224 1188 7.68 15.49 12.32 13.90 7.55 7.63 7.59 1161 1136 7.59 14.03 12.17 13.10 7.62 7.50 7.56 1168 1106 7.56 14.11 11.57 11.84 7.35 7.18 7.26 1118 1055 7.26 12.75 11.22 11.99 7.14 7.08 7.11 1080 1051 7.11 15.09 12.00 13.55 7.14 6.93 7.03 1041 998 7.03 14.03 10.17 12.10 S.Em± 0.36 0.29 0.23 80.60 87.02 59.30 0.78 0.83 0.57 CD @ 5% NS NS NS NS NS NS NS NS NS NS - Non significant; * Figures in the parenthesis indicates arcsine transformed values; - Pollination at 9.00 to 11:00 am; - Pollination at 11.00 am to 1:00 pm; - Pollination at 1.00 to 3:00 pm; - Two female flowers per male; - Four female flowers per male; - Six female flowers per male; - Eight female flowers per male; - Ten female flowers per male. percentage, root length, shoot length, vigour index and seedling dry weight were more in the 4:1 ( ) crossing ratio followed by 6:1 ( ) and 2:1 ( ) ratios. All these quality parameters were less in the 10:1 ratio ( ). The increase in seed quality parameters in 4:1 ( ) crossing ratio may be ascribed to the higher fruit set and seed number coupled with seed weight. Similar findings were also reported by Chattopadhyaya (2000) and Chen (2003) in brinjal and Yogeesha et al. (1999) in tomato. In general, pollination at 9:00 to 11:00 am was found to be optimum for hybrid seed production of the hybrid as it had recorded better fruit set, fruit weight, seed number, seed germination, vigour index and seedling dry weight compared to the pollination at 11:00 am and 1:00 pm irrespective of the crossing ratio. It is
12 INDIAN JOURNAL OF AGRICULTURAL RESEARCH evident that pollination of four female flowers with one male flower, (4:1) crossing ratio ( ) was found to be more ideal by registering superior seed quality parameters as compared to other pollination ratios in brinjal hybrid seed production. REFERENCES Anonymous (1996). Seed Sci. Tech., 29(Supp.): 1-135. Anonymous (2004). Production Year Book, Food and Agriculture Organisation, 54:148-149. Bahaduri, P.N. (1951). Indian J. Gen., 11: 75-82. Chattopadhyay, A. (2000). J. Intera-academicia, 4 : 470-473. Chen, N.C. (2003). Training Guide, Taiwan, pp. 10-14. Gomez, K.A. and Gomez, A.A. (1984). Statistical Procedures for Agriculture Research. 2nd Ed., A Wiley Interscience Publication, New York (USA). Jolli, R.B. (2004). Ph.D. Thesis, University of Agricultural Sciences, Dharwad. Padda, D.S. and Singh, J. (1971). Indian J. Agric. Res., 5: 217-218. Panse, U.G. and Sukhatme, P.G. (1967). Statistical Methods for Agricultural Workers. ICAR, Pub., New Delhi, India. Petrova, H.R. et al. (1981). Acta Hort., 111: 275-280. Rai, M. et al. (1995). Catalogue on Eggplant (Solanum melongena L.) germplasms part I. National Bureau of Plant Genetic Resources, Pusa Campus, New Delhi, pp. 1-3. Vavilov, N.I. (1931). Bull. App. Bot. (GPB), 26: 3-44. Yogeesha, H.S. et al. (1999). Seed Sci. Tech., 27: 115-122.