Depiction of genetic divergence in rice (Oryza sativa L.)

Abstract. The nature and magnitude of genetic divergence in 40 rice (Oryza sativa L.) genotypes for twelve yield and yield component were assessed using Mahalanobis D2-statistics. The analysis of variance revealed highly significant differences for all the characters under studied, indicating that there is an ample scope for isolation of promising lines from present gene pool for yield improvement. On the basis of D2 values the genotypes were grouped into seven clusters. Cluster VI was the largest containing 11 genotypes followed by cluster III with 9 genotypes. The composition of clusters indicated non existence of correspondence between genetic diversity and geographical distribution. Plant height, biological yield and test weight contributed considerably, accounting for 86.16 % of total divergence. The highest intercluster distance was observed between cluster II and VII therefore the genotypes from cluster II (Triguna, MAUB-15, Pant dhan-6) having desired mean values for characters like days to 50% flowering, panicle length and harvest index, were more divergent from the genotypes of cluster VII (Sonachur & Mala) having desired mean values for plant height, flag leaf width, spikelets per panicle, biological yield and test weight, may be used in hybridization programme to achieve desired segregants with higher yield.