Abstract
A 5x5 complete diallel experiment was conducted involving five spring wheat varieties/lines viz., Waton, Uqab,
Inqlab-96, Inqlab-91 and Bhakkar-2000 to evaluate genetic nature of various polygenic characters. The
characters under studied were plant height, number of tillers, spike length, number of spikelets per spike, grains
per spike, 1000 grain weight, and grain yield per plant. The analysis of variance showed highly significant
differences among the genotypes for all the characters studied. The graphic representation of variance (Vr) and
covariance (Wr) depicted that spike length, number of spikelets per spike and grains per spike were under the
control of additive type of gene action with partial dominance. While all other characters under study, were
governed by over-dominance type of gene action. Epistasis was found to be absent in the entire traits under
study.
