Winter × spring wheat hybridization - a promising avenue for yield enhancement

Introgression of the winter gene pool into spring wheat is being considered as one of the strategies to break through the yield plateau. However, little information is available on the combining ability of these two important but distinct groups of wheats in Indian conditions. Therefore, the present study was undertaken to determine the combining ability and gene action of yield and yield attributes in winter × spring wheat crosses. Seventy F₁ progenies developed by 14 winter and five spring wheat lines using a line × tester design were evaluated, along with their parents, for yield and yield attributes in a randomized complete block design under field conditions. The mean squares for all the characters studied showed highly significant differences. The mean squares due to female × male interactions were significant for all the characters studied except for grains per ear and grain weight per ear. Additive genetic effects were found to play a key role in controlling the expression of days to heading, plant height and spikelets per ear.‘MV 19’ and ‘Stepniak’/‘Karvuna’ among winter and ‘PBW 65’ among spring wheats were good general combiners for most of the yield attributes studied. The estimates for specific combining ability effects suggested that, although general combining ability (GCA) effects of most winter wheats are either average or poor, their combination can give desirable genotypes with spring wheat parents possessing a high GCA.