Evaluation of Genetic Diversity an Interrelationship Among Rice (Oryza Sativa L.) Collections Using Rapd And Microsatellite Markers

Abstract

Present study was undbrtaken to study the genetic diversity among forty varieties of rice collected from dis~ant geographical regions of India, using. 10 primers each of RAPD and SSR molecular markers. PIC values ranged from 0. 0.519 for RM-182 to ' 0.995 for RM-40 with an average of 0.737. The primer RM-40 was observed to be highly polymorphic (PIC value of 0.995) and RM-182 expressed minimum polymorphism (PIC value of 0.519). The resolving power varies between 0.10 (OPC- 15) to 6.6 (OPC-7F) a~d 0.25 (RM-40) to 2.25 (RM-124) in RAPD and SSR assay, respectively. RAPD an~lysis grouped 40 genotypes of rice into four distinct groups. Group one had eleven1 accessions in it. Group second contained three accessions. I Group three contained 1 two accessions. Group four contained maximum number of accessions twenty fou~. SSR assay, grouped all the 40 rice cultivars into 5 main groups which were further divided into 9 sub groups (subgroup A to I) further into I many clusters. Groups Ill had maximum number of genotypes (16) followed by cluster II (13),_ cluster i (9) and clusters IV and V with one genotype each. In both RAPD and SSR Genotype JET -21918 expressed closeness with MAS-946. Results also show a clear distinction between indica from traditional and evolved Basmati rice varieties. In this study, the grouping of cultivars based on SSR polymorphism data and combined polymorphism data corresponds well to their known pedigree data. For example, four traditional Basmati rice varieties Basmati-370, Tarori, HB-1 and Ranbir-B had very high degree of similarity between them. The cross-bred varieties, PS-4, VB-21,· VB-22, PUSA-2511 which had been derived from crosses and back-crosses of Indica x Basmati rice showed varying levels of similarity with the traditional Basmati rice group. These cross-bred varieties may have differing levels of genetic content contributed from their respective indica parents. Other indica x Basmati cross-bred varieties, such as CSR-30 and PB-1, clustered with indica rice group, suggesting a higher level of genetic content from indica rice parent(s). Sharbati, which is commonly used for adulteration of Basmati rice, is also clustered with indica rice group. Thus the two molecular marker systems together provided wider genome coverage and were found to be better indicator of the genetic relationships.