Variabilityand associationof quantitative traitswith grain yieldin commercial and pipe line bread wheat (Triticum aestivum L.) Genotypesat kulumsa, south east Ethiopia

Abstract

Research efforts made in our country lead to the development of more than 87 bread wheat varieties.The extent of genetic variability among these released varieties of bread wheat is not yet systematically assessed. Therefore, sixty four bread wheat genotypes (52 released varietiesand 12 pipe lines) were tested in a simple lattice design at Kulumsa Agricultural Research Center during 2014/15 main cropping season with the aim of studying the extent of genetic variation and association among grain yield and yield related traits. The genotypes showed significant variation for all the traits studied 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. The phenotypic coefficients of variation values were higher than genotypic coefficients of variation values. 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. Principal components (PC1 to PC6) having Eigenvalue greater than one (significant), accounted77.20% of the total variation. Grain yield showed positive and significant correlation with 1000 kernel weight, harvest index and hectoliter weight at both levels. Path coefficient analysis revealed thathigh positive direct effect was exerted by harvest index and days to maturity which had positive correlation with grain yield. These two characters can be considered for selection.According to their mean performance, genotypes Alidoro (5955.0 ± 480.83261a), Dure (5627.5 ± 604.57630ab) and Sanate (5322.5±781.35299abc) and Menze (2115.0 ±183.84776o), Digelu (2652.5 ± 562.14989no), Laketch (2870.0 ± 42.42641mno) were the best and the least yielders, respectively. 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.