Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 221 005
*Present address: Department of Botany, D. N. College, Meerut (U. P.).
Combining ability effects and variances were estimated over generations (F1, F2 and F3) and over six different environments. Both GCA and SGA variances were important for controlling the traits studied. However, the preponderance of additive gene effects (GCA variance) was noted for all the characters. The estimates of GCA X environment variances were generally higher than those of the SCA X environment variances. It shows that the additive variance X environment interaction was more as compared to the non-additive variance X environment interaction. In general, the relative proportion of the additive genetic variance was higher than those of the dominance genetic variance in F2s and F3s generations as compared to F1s. ‘NP 876’ was observed good general combiner for grain yield, number of grains per spike, spike length and earliness. ‘Sonalika’ was good combiner for grain yield, grain weight, spike length, dwarfness and earliness. ‘Kalyansona’ was for grain yield, number of grains per spike, spike length and dwarfness. The crosses involving good X good and good X poor combiners threw more productive lines. The population performance of a line is more important than its single plant performance. Diverse good combiners should be used for hybridization and the resultant material should be exposed to different environments for identifying the stable high yielding genotypes.
