Inheritance of grain yield and its correlation with yield components in bread wheat (Triticum aestivum L.)

The inheritance of grain yield plant -1 and its correlation with other yield components were investigated in a diallel cross of seven wheat parents during the crop season of 2011-2012. Mean square of GCA effect was 2.90 for grain yield plant-1, which was highly significant (P<0.01), indicating that additive effect played important role in the inheritance of the trait. SCA effect was also highly significant (P<0.01) for grain yield plant-1 (0.68), suggesting that the trait was also controlled by non-additive effect. The estimates of GCA showed that the best combiner for grain yield plant-1 was Ningmai 9. The additive-dominance model was partially adequate for grain yield plant-1 and it was controlled by the over dominance type of gene action. Ningmai 8 possessed maximum dominant genes, whereas Yangmai 9 had maximum recessive genes. Grain yield plant-1 might be controlled by two groups of genes and exhibited moderately high value of narrow sense heritability (h2N=69.51%). The statistical analysis revealed that grain yield plant-1 was positively and significantly correlated with tillers plant-1 (rp=0.584, rg=0.595) and number of grains spike-1 (rp=0.528, rg=0.507) at phenotypic and genotypic levels.