Pattern of Inheritance in Some Yield Related Parameters in Spring Wheat (Triticum aestivum L.)

An experiment was conducted using 5×5 diallel crosses in wheat to evaluate five wheat genotypes and to analyze the gene action for yield and its components. Highly significant variability was observed among genotypes for various studied parameters. The additive component and non additive parts were significant for all the traits showing the importance of both these components in inheritance of the studied traits. The graphical representation showed that tiller number for each plant plant, height of plant, length of spike, grain number per spike and weight of 1000 grains were controlled by partial dominance with additive type of gene action. Over-dominance was observed in peduncle length, area of flag leaf and weight of grains per spike. Complete dominance was observed for spikelet number per spike and grain yield on per plant basis. Non-allelic interaction was absent for all the traits studied. The distribution of dominant and recessive genes for yield traits was also studied and noted that line 9437 being closet to the origin had maximum contribution of dominant genes for grain yield per plant. The estimates of narrow sense heritability (h2(n. s)) were higher for plant height, length of peduncle and grain number per spike indicating better chance for improvement following selection procedure in these traits. The traits governed by additive genes and partial dominance should be selected in early segregating generation. In traits showing over dominance, delayed selection would be better to practice.