Gene Action and Combining Ability for Seed Yield and its Components in

Abstract: In order to study the combining ability, type of gene action and partition the components of the genetic variance to its constituents of additive and dominance gene effects using half diallel cross for eight genotypes to produce twenty eight sesame crosses. Two field experiments were carried out during two summer growing seasons 2016 and 2017 at Arab El-Awammer Research Station, Assuit, Agricultural Research Center. Results showed that mean squares due to both general (GCA) and specific (SCA) combining ability were highly significant for all characters, indicating the importance of both additive and non-additive gene effects in the inheritance of studied traits. The ratio of GCA/SCA indicated that the largest part of the total genetic variability due to the additive and additive x additive was very important than the non-additive gene effects in the genetic variability for all studied traits. Estimates of GCA for eight parents revealed that P8 was good combiner for plant height, length of fruiting zone, seed yield/plot and number of days to 50% flowering, while P1, P2 was good combiner for number of capsules/plant, seed yield/plant and 1000-seed weight. Significant SCA effects were observed for some crosses, cross (P1xP5), (P1xP7) and (P2xP3) were the best ones for seed yield/plant. Additive "D" and dominance (H1 and H2) genetic variation were significant for plant height and seed yield/plot. The "D" parameter estimating the additive effect was highly significant and was larger in magnitude than the dominance parameters (H1 and H2) in the all studied traits indicating that the type of gene action is partial dominance. The positive and negative alleles were unequally distributed among the parents. All studied traits had a high values for the broad sense than the narrow sense heritability. Graphical analysis revealed that the regression lines cuts Wr axis above origin point, indicating partial dominance for all the studied characters.
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Publication year 2018
Pages 695 - 702
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Author(s) from ARC
Publication Type Journal
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