Genetic Variability in Bread Wheat (Triticum aestivum L.) Germplasm for Yield and Yield Component TRAITs

The overall objective was to study the extent of genetic variation and association among grain yield and yield related traits. Sixty eight germplasm of bread wheat were tested in an augmented design. The Germplasm showed significant variation for treatment adjusted, for most test entries and test versus control studied and relatively wide range of the mean values for most of the characters indicated the existence of variations among the tested germplasm. The phenotypic coefficients of variation values were higher than genotypic coefficients of variation values. High PCV and GCV were recorded for productive tiller, spike length, kernel per spike, 1000 grain weight, biomass yield, harvest index and grain yield. High heritability values were observed for all the characters studied. Among the characters heading date, grain filling, spikelet spike - , 1 spike length, kernel per spike, 1000 grain weight, harvest index and grain yield had high values of genetic advance as percent of mean (GAM). The D 2 analysis showed the 68 germplasm clustered into six clusters. This shows the germplasm to become moderately divergent. Principal components (PC1 to PC3) considered eigenvalue greater than one (significant), accounted nearly 63.2% of the total variation.. Based on these result we cannot reach to the final decision. But it can be used as a bench mark for further study. Therefore; it needs additional study over several years and multi locations. Keywords: Germplasm, PCV, GCV, Heritability, Genetic advance, principal component, diversity.