Gene action estimation in half-diallel crosses of yield traits in eight sesame genotypes

Abstract: Development of high yield genotypes is one of the most important aims of sesame breeding programs. This study was carried out during 2016 and 2017 growing seasons in order to determine the genetic behavior of sesame set of 28 diallel F1 crosses and their parents. Genotypes were grown in Toshka Research Station Farm, South Valley, Egypt. Results elucidated a highly significant variation among genotypes, indicating a wide genetic variability for the studied traits and the possibility of genetic improvement using such genetic pools of sesame. The (GCA/SCA) ratio indicated great additive gene action for all studied traits. Parents: Introduced 589, Sohag 1, Shandweel 3 and Line119 were identified as good general combiner, whereas crosses (Shandweel 3 x Local 535), (Line11 x Line119), (Line119 x Local 535), (Sohag 1 x Shandweel 3) and (Introduced 142 x Introduced 589) were the best specific combiner for seed yield and its component traits. Additive (D) and dominance (H1) component of genetic variability were highly significant for most traits; however H1 estimates were greater than D, resulting in the average degrees of dominance (H1/ D)0.5 were more than unity, indicating, the role of over-dominance gene effects in the inheritance of the studied traits. Value of H1 was greater than H2, resulting in H2/4H1 that was below (0.25), indicating that positive and negative alleles at loci for these traits were not in equal proportional for parents. The covariance of additive and dominance effect (F) coupled with ratio of dominant/recessive alleles in the parents KD/KR was greater than one for most traits, indicating that the recessive genes were more in the parents than dominant ones. Narrow sense heritability recorded moderated estimates ranged from 0.29 to 0.68, meaning probability improvement some yield-related traits in sesame through selection.
Publication year 2018
Pages 43-58
Organization Name
Author(s) from ARC
Publication Type Conference/Workshop