Inheritance of Spike Number in Wheat

Inheritance of spike number per plant was studied in two crosses of wheat (Triticum aestivum L.) involving dwara strains frfm Mexico and improved cultivars of India. The parental, F₁, F₂, F₃, BC₁ and BC₂ generations of two crosses, Kalyan 227 × C 281 and S 310 × C 273, were grown under normal and late sowings.

In most cases, the F₁ generation was superior than the mean of the parents for spikes per plant. Additive, dominance, and epistatic genetic effects were detected in the cross S310 × C 273, but epistatic effects were of less importance in Kalyan 227 × C 281. Both additive × additive and additive × dominance types of interactions were significant, however, the former was of much greater magnitude than the latter. As the environmental influences were also found to be quite important it would be necessary to test the material at several locations and grow larger populations in the segregating generations for adequate selection.