Combining Ability Analysis for Seed Yield per Plant and its Contributing Traits in Castor (Ricinus communis L.)

Abstract— A line × tester analysis of twenty four hybrids developed by crossing four lines and six testers were carried out under three diverse environments. The components of genetic variance were estimated from the analysis of variances for combining ability of different characters for each environment and pooled also. The analysis of variance for combining ability individual as well as pooled over environments revealed that mean squares due to lines and testers were significant for most the characters, Line × Tester was significant for all the characters except seed yield per plant and estimated genetic variance due to GCA and SCA was non-significant for all the characters in pooled over environments. The ratio of σ2gca/σ2sca was less than unity which revealed the predominant role of non-additive gene action for inheritance of the traits for days to flowering, days to maturity, number of nodes up to primary raceme, effective length of primary raceme, seed yield per plant and 100-seed weight. Therefore, heterosis breeding may be suggested to exploit hybrid vigour and recombinant in F2 and subsequent generations for isolating lines for seed yield and its contributing traits. The line SKP 126 and tester SKI 420 were found as good general combiners for the yield attributing characters in pooled over the environments. Among the crosses, best three specific combiner were SKP 120 × SKI 420, SKP 126 × SKI 357 and SKP 106 × SKI 412 for seed yield per plant and its contributing traits.