Winter and Spring Wheat: An Analysis of Combining Ability

Wheat (Triticum aestivum L. em. Thell) is main source of calories for more than 1.5 milliard people in the world. During last 4 decades wheat production and productivity increased almost six times in the Indian subcontinent. Despite this, it is being felt that wheat yield has attained stagnation. In order to overcome this, introgression of winter wheat gene pool into the cultivated spring wheat has given encouraging results. However, little information is available on the combining ability of these two important but otherwise, distinct groups of wheat. The present study was, therefore, undertaken to determine the combining ability and gene action of yield and yield attributes in winter × spring wheat crosses. Twenty-four Fi progenies developed by 8 winter and 3 spring wheat lines using line × tester design were evaluated along with their parents, for yield and other components. 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 days to maturity. Additive genetic effects were found to play a key role in the genetic control of days to heading and days to maturity. Maldova and Marisdoe among winter and NP 846 and NP 4 among spring wheat were good general combiners for most of the attributes studied. Cross Marisdoe/NP 809, Burgas-2/NP 846 Stepoa/NP 846 and TW 238/62/7/9/3/NP4 had significant specific combining ability effects for most of the yield attributes. The estimates of specific combining ability suggested that although general combining ability effects of most winter wheats are either average or poor, their combination with spring wheat parents possessing high GCA could give desirable genotypes.