M. KHALEQUZZAMAN1, KHALEDA AKTER1, S. KHATUN2, M.R.A. SARKER1 AND S.H. HABIB1
1Genetic Resources and Seed Division, Bangladesh Rice Research Institute, Gazipur-1701 and 2Plant Breeding Division, Bangladesh Rice Research Institute, Gazipur-1701
Abstract
Fifty rainfed lowland (T Aman) rice genotypes originating from southwest region of Bangladesh were subjected to cluster analysis. The genotypes were constellated into six distinct groups with the range of 4 genotypes in cluster IV to 16 in cluster III. The inter-cluster distance in most of the cases was larger than the intra-cluster distance suggesting wider genetic diversity among the genotypes of different groups. Maximum inter- cluster distance was observed between genotypes of cluster II and I followed by cluster IV and I; cluster VI and II; cluster V and II and the minimum was found between genotypes of cluster VI and V. The highest intra cluster value (4.98) was observed in cluster III due to the presence of highest number of genotypes and presence of variations among them. Mean performance of different clusters revealed that filled grains/panicle, plant height, panicles/hill and yield (t/ha) were higher in cluster I to get highest divergence between cluster I and II. As a result, cluster I also showed high divergence with cluster IV. The genotypes in cluster II showed high divergence with V and VI due to highest grain length, breadth, 1000 grain weight, harvest index and grain yield in V and VI. The genotypes in cluster II and III showed moderate inter-cluster distance with those in cluster III and IV respectively. The genotypes in cluster I showed high inter-cluster distance with those in cluster II and IV and the genotypes in cluster II also showed high inter cluster distance with those in V and VI indicating the possibility to obtain heterotic progenies with high yielding ability along with desirable traits if the genotypes from former clusters are crossed with those from the latter ones.
Key word: Genetic divergence, D2 analysis, cluster analysis and rice (Oryza sativa L.)