Genetic Variability Studies in Bread Wheat (Triticum Aestivum L.) Genotypes at Kulumsa Agricultural Research Center, South East Ethiopia

Abstract

Sixty four bread wheat genotypes were tested in a simple lattice design at Kulumsa Agricultural Research Center during 2014/15 main cropping seasonto estimate the extent of genetic variability. The genotypes showed significant variation for all the traitsstudied except for biomass yield ha^-1 and relatively wide range of the mean values for most of the characters indicated the existence of variations among the tested genotypes.Moderate PCV and GCV were recorded for 1000 kernel weight, grain yield, harvest index, number of grains spike^-1 and number of productive tiller. High heritability values were observed for days to heading, days to maturity, grain filling period, 1000 kernel weight, number of spikelet spike^-1, spike length and plant height. Moderate PCV and GCV were recorded for 1000 kernel weight, grain yield, harvest index, number of grains spike^-1 and number of productive tiller. Among the characters 1000 kernel weight showed high values of genetic gain whereas days to maturity, grain yield, harvest index, productive tillers and number of grains plant^-1 had moderate  values of genetic advance as percent of mean (GAM). The D² analysis showed that the 64 genotypes were clustered into nine clusters. Maximum inter cluster distance was observed between cluster I and IX (D²=5112.1), followed by that between clusters III and IX (D²=4694.4) and VIII and IX (D²=3871.9) which had shown they were genetically more divergent from each other than any other clusters. Crosses between genotypes selected from cluster I with cluster IX, cluster III with cluster IX and cluster VIII with cluster IX are expected to produce relatively better genetic recombination and segregation in their progenies.Principal components (PC1 to PC6) having Eigenvalue greater than one (significant), accounted 77.20% of the total variation. The first two principal components PC1 and PC2 with values of 22.3% and 17.4% respectively, contributed more to the total variation. According to their mean performance, genotypes Alidoro (5955.0 ± 480.83261a), Dure (5627.5 ± 604.57630ab) and Sanate (5322.5±781.35299abc) were the best yielders. The present result is only an indication and we cannot reach a definite conclusion. Therefore, it is advisable to continue with this study over several years and locations.

Keywords: Genetic variability, Heritability, PCV, GCV, Genetic advance