Detection of Additive, Dominance and Epistatic Variation Using Single Tester Analysis in Breadwheat

Single-tester analysis of material generated from five bread wheat varieties, sown on two dates, was performed for five metric traits. With the availability of F₂₁ generation, five additional tests of epistasis were constructed, including three tests detecting additive × additive (I), additive × dominance (J), and dominance × dominance (L), kinds of epistasis individually in the single tester analysis. The epistatic variation was an important part of genetic variation for all traits. The significant epistasis was of I type for ear length, I and L type for ear number, J and L type for days to flowering, and only L type for height at flowering and total plant height. The epistasis × sowings, additive × sowings, and dominance × sowings interactions were all nonsignificant. The additive and dominance components were equally important for days to flowering and height at flowering, while the additive component was predominant for plant height and ear number. For ear length, only the additive component was significant. Because of presence of large additive component along with fixable nonallelic interactions simple breeding procedures like single seed descent method could be used for obtaining superior recombinant pure breeding lines.