Combining Ability for Grain Quality in Spring Wheat

General and specific combining ability variances and effects for four quality characters in wheat (Triticum aestivum L.) protein content, Pelshenke value, lysine and tryptophan contents were studied in diallel F₁ and F₂ progenies of untreated and EMS (0⋅4%) treated diverse five spring bread wheat cultivars. Both additive and nonadditive genetic variances were important in the inheritance of the traits under study. ‘Norteno M 67’ for protein content, ‘Norteno M 67’ and ‘NP 876’ for Pelshenke value, ‘NortenoM 67’ and ‘S 331’ for lysine content and ‘Kalyansona’ for tryptophan content, were the best general combiners. The estimates of SCA effects were lower in magnitude in the F₂ than in the F₁ populations. Most of the crosses showing significant positive SCA effects involved one good and one poor, or even negative, general combiner.