Characterization among bread wheat (Triticum aestivum L.) Landraces at kaffa zone, south west ethiopia

Abstract

Bread wheat landraces have high level of genetic diversity which provides high degree of resistance to biotic and abiotic stresses. Despite the diversity of bread wheat in Ethiopia, the production of wheat in Kaffa Zone is very low compared to national average production. The low production of wheat is due to lack of adaptive high yielding variety. The present study was initiated with the overall objective of characterization of bread wheat for quantitative and qualitative traits and determination of genetic diversity. The study was conducted on hundred bread wheat landraces with three checks. The plots were laid out in an augmented design. The analysis of variance showed significant (P< 0.05) difference for all of the traits. This indicated the existence of variability and hence the potential for selection and improvement. The mean performance of the accessions indicated that accession number 29812 gave a higher grain yield than the other accessions. According to the mean performance, accessions 29812, 29811, 29813, 242427, 242429 and 243702 that performed better than the released check varieties for grain yield. Moderate genotypic and phenotypic coefficient of variation were observed for spike length, number of seeds per spike, biomass yield and harvest index. Number of productive tiller and grain yield were found to have a high phenotypic coefficient of variation. Moderate to high heritability coupled with moderate to high genetic advance as per cent of the mean were observed for spike length, number of seeds per spike, thousand seed weight, biomass yield and harvest index. This means effective and satisfactory selection for practical improvement of these important traits is possible. Grain yield showed positive and significant correlation with grain filling period, number of productive tillers, spike length, number of seeds per spike, thousand seed weight and biomass yield. Positive correlations of grain yield with the major yield components give an opportunity to simultaneously improve yield and yield contributing traits. Thousand seed weight and number of productive tillers exerted a favorable direct effect on grain yield at genotypic and phenotypic level. Selection for number of productive tiller and thousand seed weight would be very useful for grain yield improvement of bread wheat. The principal component analysis grouped all the traits into four principal components accounted a cumulative of 74% for total variation. The accessions were clustered into seven clusters and one ungrouped accession. Among the clustered groups, the highest inter cluster distance was observed between cluster IV and cluster VI ((D2=104.77)) indicating the possibility for selecting parental genotype for hybridization. The estimated diversity index showed the presence of polymorphism. The highest (0.99) diversity index was obtained for seed size, possibly indicating the differential responses of the accessions to the varying environment. However, the present result is only an indication and cannot draw definite conclusion. Thus, for more reliability the experiment should be repeated over location and seasons