Combining ability analysis for yield and its components in bread wheat (Triticum aestivum L.)

Combining ability was analyzed using a line × tester (8 × 4) analysis in bread wheat (Triticum aestivum L.). Combining ability analysis, revealed the importance of both additive as well as non-additive genetic variances for control of various traits. The potence ratio (σ2gca/σ2sca) suggested the preponderance of additive gene actions for number of effective tillers per plant, length of main spike, number of spikelets per main spike, number of grains per main spike and 100-grain weight and non-additive gene actions for rest of the traits. Parent MP 3288 was the best general combiner, whereas crosses MP 3288 × GW 496 and MP 3288 × GW 366 were found to be the best specific combiners for grain yield per plant and some of the yield contributing traits. However, on the basis of per se performance and significant SCA effects for grain yield per plant and some of its important components, hybrids MP 3288 x GW 366, MP 3288 x HI 1544 and GW 173 x GW 451 were considered to be the most promising for further exploitation in breeding programmes.