Genetic divergence analyses of lowland rice genotypes in North Western Ethiopia

Information on the nature and magnitude of genetic variability is one of the prerequisites for a successful breeding program in selecting genotypes with desirable characters. To estimate the level of genetic divergence of lowland rice genotypes, a field experiment was conducted using thirty-six genotypes during 2017 main cropping season. The experiment was laid out 6x6 simple lattice design. Analyses of variances showed significant differences among traits tested, except harvest index. Principal components PC1, PC2 and PC3 accounted for 64.16% of the total variation. The highest inter-cluster distance was exhibited between cluster I and IV (D2 = 769.77), cluster I and VI (D2=485.33), cluster I and III (D2=232.35), cluster III and IV (D2=312), cluster III and VI (D2=197), cluster IV and VI (D2=746.51), cluster VI and V (D2=259.51) and cluster VI and VII (D2=140.15). The crosses between genotypes selected from cluster I with clusters IV, VI and III; cluster IV with clusters III, VI and V are expected to produce better genetic recombination and segregation in their progenies. The cluster means for cluster VI and I were characterized by early heading and early maturity. While cluster I, II, III, and IV were characterized by high mean performance for grain yield for most of its components.   Key words: Cluster analysis, divergence, genetic distance, principal component, rice.