Combining ability of barley genotypes in diallel crosses

Combining ability analysis in barley (Hordeum vulgare L.) involving nine diverse parents and their 36 F-1 and F-2 progenies indicated significant differences among the parents for gca and among crosses for sca for all the characters studied. The gca and sca components of variance were significant for all the traits. The gca/sca ratio showed preponderance of non-additive gene actions for characters, namely, days to maturity, plant height, effective tillers per plant, biological yield per plant, grain yield per plant, and harvest index. However, additive gene action was more pronounced for days to heading and test weight. Among the parents, RD 2508, RD 2552, and RD 2503 were the best general combiners for grain yield and were average to high combiners for other important traits. The best specific crosses for grain yield were 131, 2 x IBVT 12, RD 2552 x RD 2035, RD 2503 x IBVT 7, RD 2503 x IBVT-8, RD 2035 x RD 103, RD 103 x IBVT 7, RD 2508 x RD 103, RD 2503 x RD 103, IBVT 12 x IBVT 7, RD 2552 x RD 103, and RD 2508 x IBVT 12. To ensure further increase in grain yield, combining desirable yield components is advocated. The exploitation of additive and non-additive gene actions through bi-parental mating and/or diallel selective mating systems is suggested for tangible advancement of grain yield in barley.