Combining Ability in F1 Generation for Diallel Crosses for Yield and Yield Components in Wheat (Triticm aestivum, L.)

The combining ability and heterosis have been analyzed in a 6-parents  F₁ diallel cross for yield and its components.  The experiment was conducted at the Experimental Fam., Faculty of Agricultural, Al-Azhar University(Assiut Branch). The analysis of  variance indicated highly significant differences in among 21 enter for plant height, number of spikes/plant, spike length (cm), grain weight/spike,(gm), 100-grain weight(gm) and grain yield/plant(gm). Variance due to general combining ability as well as specific combining ability were highly the above mentioned traits. However, the ratio of genetic components ∑gi² /∑sij² was less than unity of the non-additive genetic variance in the inheritance of all the above traits. Heterosis effects over mid and better parents were shown in F₁ hybrid for all studied characters.