Study of combining ability for yield and its contributing traits in bread wheat [Triticum aestivum (L.)]

Abstract

An experiment on combining ability for yield and its contributing traits in wheat [Triticum aestivum (L.)]” was carried out through Line x Tester analysis at Centre for Crop Improvement, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar. Experimental materials comprising twelve parents, thirty-two crosses and one tester, GW 496 as standard check were planted in a randomized block design with two replications during rabi 2012-13 season. The analysis of variance for experimental design revealed that highly significant differences were existed among genotypes, parents and hybrids for most of traits. The analysis of variance for combining ability revealed specific combining ability variances for m x f interaction were highly significant for plant height, number of effective tillers per plant and grain yield per spike. The magnitude of general combining ability variances was higher than the specific combining ability variances for all the characters which indicated preponderance of additive gene action in the inheritance of these traits. This was further supported by high magnitude of σgca / σ2sca ratios. On the basis of general combining ability (gca) effects none of the parent was good general combiners for all the characters. Among female  GW 11 and male GW 322 was found to be good general combiner for grain yield per plant, harvest index and protein content, respectively. Six males showed significant general combining ability effects of which, GW 190 (4.85) and GW 322 (3.13) showed significant positive general combining ability effects for grain yield potential. In case of GW 503 (1.00) exhibited significant positive general combining ability effect for grain yield per plant. The results of specific combining ability effects of different cross revealed that none of the crosses showed significant and negative specific combining ability effects for days to 50 per cent heading, days to maturity and plant height and significant and positive specific combining ability effect were observed for number of effective tillers per plant, length of main spike and grain yield per spike. In case of SCA hybrids viz., GW 11 x GW 273 (0.42), GW 11 x GW 190 (0.35) and GW 173 x GW 438 (0.34) exhibited significant positive specific combining ability effects. Therefore, these crosses are revealed as good general combiner and can be utilized in breeding for improvement in yield and its contributing traits in wheat crop.