MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF TUNGRO RESISTANT GENOTYPES OF RICE

Abstract

Genetic divergence analysis through Principal Component. Principal Coordinate and Canonical Vector analyses were done for tungro resistant and susceptible genotypes using 13 morphological characters. The genotypes were grouped into six clusters according to D2 statistic and Canonical Vector analysis Plant height, days to flowering, days to maturity, panicle length. number of spikelet per panicle number of unfilled grain per panicle and yield were mdicated as important contributiors to genetic divergence in 14 rice genotypes. On the basis of cluster distances, cluster l (BR10, BRRI dhan44) with cluster ill (Sonahidernota, Kumragoir, Nakuchimota) and cluster VI (Bazail Ace 252, bazail Accl7l, Rayeda 4849) or cluster l1 (BRI I, BRRI dhan3 l , BRRI dban32) with cluster Ill were identified for utilization in hybridization programme. A total of six primers including three SSRs and three VNTRs were used to characterize tungro resistant genotypes. PIC values of SSR primers, RM20, RM21 and RM23 ranged from 0 65-0 84 So these primers were considered as very much useful for characterizing tungro resistant genotypes The amplicons size of RM2 l (I 86 bp) was found in tungro susceptible. BR 10 and moderately resistant genotypes while that was absent in highly resistant and susceptible, BRI I genotypes. In Vlx'I'R primer GF, two amplicons {543 bp and 1003 bp) were fixed with susceptible and moderately resistant varieties while those were absent in highly tungro resistant vaneties. Based on Nei's genetic distance, seven clusters were formed among the tungro resistant genotypes Diversity analysis of genotypes using morphological and molecular data indicated that new breeding program could be initiated preferably using the parents. BRRl dhan44 and Kachamota, BRRI dhan32 and Kacharnota, BR l 0 and Kachamota, BRRl dhan3 1 and Kacharnota, BRRI dhan32 and Sonahidernota for the development oftungro resistant varieties.