Estimation of combining ability and gene action in feed barley (Hordeum vulgare L.) using line × tester analysis

Thirty hybrids generated from crossing ten lines with three testers were studied along with their parents for combining ability and gene action involved in the expression of characters in feed barley to identify suitable parents and desirable hybrid combinations. Observations were recorded for days to heading, days to maturity, plant height (cm), spike length (cm), peduncle length (cm), flag leaf area (cm²), number of grains per spike, grain yield per plant (g), 1000-grain weight (g), biological yield per plant (g) and harvest index (%). The female parents (lines) viz., PL 842, BH 933, RD 3012 and HUB 272 were found good general combiner for yield and its attributing characters. While for the male parents (tester) K 944 and RD 2552 were found good general combiner for yield contributing traits. The specific combining ability effects of different crosses revealed that none of the crosses showed consistently significant and desirable specific combining ability effects for all the characters. The cross RD 3012 × RD 2552 showed significant and desirable specific combining ability for all the characters viz., days to heading, spike length, peduncle length, flag leaf area, number of grains per spike, grain yield per plant, 1000 grain weight and harvest index and adjudged as auspicious cross. The cross BH 933 × K 944 exhibited significant sca effect for all characters viz., days to maturity, spike length, peduncle length, flag leaf area, number of grains per spike, grain yield per plant, 1000 grain weight and harvest index. The ratio of σ² gca/σ² sca was less than unity for all the characters under study. This showed sca variance higher than gca variance so, there was preponderance of non-additive gene action. As non-additive gene action was found to be more prominent in the present investigation, so that in addition to conventional breeding methods some non-conventional breeding methods such as diallel selective mating, bi-parental mating in early segregating generations followed by selection or multiple crosses might prove to be effective alternative approach for appreciable progress in grain yield of feed barley.