Analysis of genetic diversity in some durum wheat (Triticum durum Desf) genotypes grown in Ethiopia
An experiment was conducted to examine the magnitude of genetic diversity and characters contributing to genetic diversity among 23 durum wheat genotypes grown at Adet, northwest Ethiopia, in 2010 main cropping season. Genetic divergence was carried out according to Mahalanobis D2 statistics. Genetic distance analysis revealed that the Euclidean genetic distance values ranged from 2.69 (between D-1 and D-11) to 9.68 (between D-13 and D-21) and 82.2% of the pair comparisons had values between 3.76 and 7.50. Cluster analysis grouped genotypes into six genetically distinct clusters. The highest inter-cluster distance was 8.30 (between clusters III and VI) followed by 7.99 (between clusters V and VI), indicating the wide genetic diversity among these clusters. The highest intra-cluster distance was observed in cluster I (4.91) and the lowest in cluster III (2.36). The average inter-cluster distances were higher than the average intra-cluster distances, which showed the presence of wide genetic diversity among the genotypes of different clusters than those of the same cluster. The first four principal components whose Eigen values are greater than one, accounted for 80.46% of the total variation of the original variables. The information obtained from the study is useful in planning further crossing programme for durum wheat crop improvement.
Key words: Cluster analysis, genetic distance, principal component analysis.