Genetic diversity in lowland aman rice (Oryza sativa L.) in West Bengal

A quantitative assessment using Mahalanobis D2 statistics for genetic diversity in 36 long duration aman rice grown under rainfed semi-deep situation at new alluvial zone of West Bengal with respect to twelve morphological characters revealed that the genotypes could be grouped into seven clusters. Cluster I with 25 genotypes was the largest, whilecluster VII was mono-genotypic. Cluster II, III, IV, V and VE had two genotypes each. The maximum inter-cluster distance was recorded between cluster II and VII. Cluster I revealed to be most heterogeneous. Grain yield plant−1 contributed maximum (35.39%) to the total divergence, followed by 1000-grain weight (33.49%) and grain length (17.61%). Hybridization among the genotypes, viz. Heymant, Murkibalam, Suranagra, Sungakalma and KGR belonging to widely divergent clusters are likely to produce heterotsis and wide variability in segregating generations.