Inheritance of plant height and spike length in dwarf spring wheat

The nature and magnitude of genetic variances controlling plant height and spike length was worked out in diallel F₁ and F₂ progenies produced a separately from nine diverse normal and EMS treated parents of spring wheat. Both, additive and nonadditive components of genetic variances, were highly significant in all the populations for both the characters, though the magnitude of additive component was higher than the nonadditive component. Although the estimate of total genetic variance did not increase much in the treated population, the additive genetic variance (D) was increased considerably for both the characters as compared to that recorded in normal population, whereas nonadditive components (H₁ and H₂) decreased. A breeding plant which may simultaneously exploit both the additive and nonadditive gene effects would be most effective in bringing about rational improvement in the two characters.