COMBINING ABILITY ANALYSIS IN SESAME (Sesamum indicum L.)
KrishiKosh
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Title |
COMBINING ABILITY ANALYSIS IN SESAME (Sesamum indicum L.)
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Creator |
VIJAYA DURGA, G
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Contributor |
RATNA BABU, D
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Subject |
planting, oilseeds, yields, biological phenomena, sowing, developmental stages, genetics, sesamum indicum, heterosis, additives
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Description |
The present investigation was carried out during kharif 2011 and rabi 2011-12 at Agricultural College Farm, Bapatla to study the variability, heritability, expected genetic advance, combining ability, heterosis, character association and path coefficient analysis of eight parents (five lines + three testers) and 15 F1s of sesamum for characters viz., days to 50% flowering, days to maturity, plant height (cm), number of primary branches per plant, number of capsules per plant, number of seeds per capsule, 1000-seed weight (g), oil content (%) and seed yield per plant (g). Analysis of variance revealed significant differences among the genotypes for all characters studied, indicating a high degree of variability in the material. The estimates of heritability and genetic advance as per cent of mean were high for the characters viz., number of primary branches per plant, number of seeds per capsule number of capsules per plant, 1000-seed weight and seed yield per plant. High heritability coupled with moderate genetic advance as per cent of mean was observed for plant height and days to 50% flowering. While moderate heritability coupled with low genetic advance as per cent of mean was observed for the characters viz., days to maturity and oil content. The analysis of variance for combining ability revealed that lines, testers, lines vs testers, crosses and Line x Tester effects had significant amount of variability within each of them for majority of traits studied. The per cent contribution towards the total variance was maximum due to the interaction of lines and testers for the traits days to maturity, 1000-seed weight, days to 50% flowering and oil content while contribution of lines alone was maximum towards the total variance for number of capsules per plant, number of seeds per capsule, seed yield per plant, plant height and number of primary branches per plant. Out of the five lines tested in the present investigation, IS 355 followed by YLM 95 recorded significant general combining ability effects for majority of the characters studied. Among the testers Gowri recorded good general combining ability effects for majority of traits. Within the 15 Line x Tester combinations, KMR 42 x Madhavi followed by IS 355 x RT 54, YLM 95 x Gowri and YLM 96 x Gowri recorded good specific combining ability effects for important yield components. The gca effects of parents and sca effects of their hybrid combinations indicated that the crosses with high sca effects were resulted due to high x low, low x low and high x high gca combinations. Therefore it is worth including some low general combiners also in hybridization programmes. Further heterosis studies revealed that four Line x Tester combinations viz., IS 355 x Gowri, KMR 42 x Madhavi, YLM 95 x Gowri and IS 355 x Madhavi registered significant positive heterosis over both mid and better parents for seed yield per plant. Though the per se performance of the parents are relatively low, the above combinations are highly heterotic indicating better nicking ability of the lines and testers involved. Majority of lines and testers which yielded heterotic hybrids registered good gca as well. With this it is evident that lines with good gca though having less per se may also yield heterotic combinations. This shows the importance of studying the combining ability effects of different lines that are to be use either in heterosis breeding or in combination and transgressive breeding. The estimates of sca and gca variance also revealed the predominance of nonadditive gene action in the inheritance of days days to 50% flowering, days to maturity, oil content and 1000-seed weight while both additive and non-additive gene actions were predominant for number of seeds per capsule, number of capsules per plant, plant height, seed yield per plant and number of primary branches per plant. These gene actions were further confirmed by the ratios of gca variance to total genetic variance and the estimates of narrow sense heritability. The traits number of capsules per plant, number of seeds per capsule, number of primary branches per plant and plant height were found to possess significant positive association with seed yield per plant at both genotypic and phenotypic levels. While path analysis studies revealed that number of capsules per plant showed true relationship by establishing significant positive association and high positive direct effect on seed yield per plant followed by number of seeds per capsule, number of primary branches per plant and plant height. From this it can be inferred that simultaneous improvement in seed yield per plant is possible through manifestation of number of capsules per plant, number of seeds per capsule and number of primary branches per plant. It can be concluded that out of the five lines tested for their combining ability the line IS 355 exhibited significant gca effects in desirable direction for the traits number of seeds per capsule, number of capsules per plant, plant height, seed yield per plant and number of primary branches per plant while another line YLM 95 also recorded good gca effects in desirable direction for number of capsules per plant, number of seeds per capsule, seed yield per plant, number of primary branches per plant and 1000-seed weight. These two lines also resulted in heterotic hybrids when test crossed with different testers used in the study. Therefore, one can utilize the above two lines either in heterosis breeding or in transgressive breeding for the improvement of respective characters in which they registered good general combining ability effects. |
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Date |
2016-06-22T11:49:06Z
2016-06-22T11:49:06Z 2012 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/67675
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Language |
en
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Relation |
D9405;
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Format |
application/pdf
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Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
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