Ninety progenies produced by crossing 30 wheat varieties/lines with three testers in a triple test-cross fashion were selfed and grown together with parents to detect various components of genetic variation and interaction of these components with sowing date for seven metric traits. The testers were adequate for days to heading, grain number, 1000-grain weight and grain yield perplant. Epistasis was observed for plant height, tiller number and spike length in both sowings. The nonfixable epistasis was more important and sensitive to environment than fixable epistasis. Generally, the additive component was equally or more important than the dominance component. Both the components were equally sensitive to the change in environment. In all cases, dominance was directional.
Genetic variation, genotype x environment interaction, triple test-eross, wheat
