Correlation and Divergence Analysis for Phenotypic Traits in Sesame (<i>Sesamum indicum</i> L.) Genotypes

Abstract

A study was conducted to determine the magnitude of associations of traits and genetic divergence among the 64 sesame genotypes. The genotypes were arranged in 8 x 8 simple lattice design and grown in Arjo district, Western Ethiopia during 2013 cropping season. Data were recorded for 12 phenotypic traits and analyzed using SAS software version 9.20 (2002, USA). The results showed that seed yield had positive and significant genotypic and phenotypic correlations with all traits, indicating they are important yield components and can be used for yield improvement in sesame breeding program except for PH and BY. Further analysis by path coefficient method indicated that at genotypic level DM, CFP and HI exerted high positive direct effects on seed yield and strong and positive correlation with seed yield. Similarly, at phenotypic level positive and high direct effects were exerted by CFP, NPB and HI on seed yield and these traits had also strong positive associations with SY. Genetic distance analysis showed that the 64 sesame genotypes were grouped in to 4 clusters and maximum inter cluster square distance (D2) was recorded between cluster I and II followed by cluster I and III. Hence crossing involving cluster I with II and cluster I and III may exhibit high heterotic values and could give transgressive segregants. The principal component analysis revealed that four principal components explained about 66% of the total variation existed among the genotypes. The dominant seed color observed was brown followed by white in the genotypes. The study generally indicated that there was significance genetic variability or divergence among the genotypes. Thus, there is enormous opportunity to use the existing genotypes for direct selection as well as using distant parents for crossing purposes to improve specific traits.