Diallel analysis using graphical & numerical approach for grain yield & its attributes in bread wheat (Triticum aestivum L.)

Ten wheat ( Triticum aestivum L.) genotypes are crossed in half diallel fashion. Components of gene effect revealed that most of the characters were governed by both additive and dominance gene effect across the environments with greater influence of dominance gene effect except for days to 50% heading, days to maturity and grain yield per main spike. The estimated ‘t 2 ’ values were found significant for all the character except days to 50% heading, which indicates the failure of assumptions of diallel analysis. The over dominance behaviour was observed for days to 50% heading, days to maturity, no. of effective tillers per plant , length of main spike, no. of spikelets per main spike, no. of grains per main spike, grain yield per main spike and 1000 grain weight. The array points on the Wr-Vr graph expected to fall on the line of unity (450) and the value of regression “b” was unity for days to 50% heading and 1000 grain weight which revealed an absence of digenic interactions for these characters and rest of the characters had non-random distribution of genes at different loci among the parents and/ or presence of inter allelic interaction at different loci.