Genetics of yield and related traits in bread wheat over different planting dates using diallel analysis

Abstract

An 8x8 diallel experiment was conducted on bread wheat (Triticum aestivum L.) to ascertain the genetic mechanism of yield and its related traits. The observations were recorded on days to heading, productive tillers plant-1, number of grains spike-1, grain yield plant-1 and 1000-grain weight. The experiment was planted in randomized complete block design in three replicates. F-test declared significantly different means for all traits. Analysis of genetic components revealed significant additive (D) and dominant (H) genetic variations for days to heading, productive tillers plant-1, number of grains spike-1, grain yield plant-1 and 1000-grain weight under all three environments. Under normal planting both additive (D) and dominant (H) components were significant for productive tillers plant-1 and grain yield plant-1, while under late planting significant additive (D) and dominant (H) components were found for number of grains spike-1. Graphical analysis revealed additive gene action with partial dominance for days to heading and 1000-grain weight under early and normal planting. Negative intercepts of regression lines indicated non-additive gene action with over dominance for days to heading and 1000-grain weight under late planting, for productive tillers plant-1 and grain yield plant-1 under normal planting and for grains spike-1 under late planting. Genetic analyses of traits confirm the involvement of additive and non-additive gene effects in governing the inheritance of these traits. Key words: Diallel analysis, genetic analysis, breed wheat, yield components of wheat.