Morphological and molecular characterization of recombinant inbred lines for dormancy related traits in rice (Oryza sativa L.)

The study was carried out to assess the genetic relatedness of 119 recombinant inbred lines along with their parents BPT 2231and MTU 1001 based on morphological and molecular characterization. Data recorded for 10 morphological characters was used for grouping genotypes into different clusters by using Tocher’s and UPGMA dendrogram methods. Under D2analysis, the genotypes were grouped into 6 clusters and out of 10 characters studied, free amino acids contributed maximum divergence followed by days to 50% flowering and test weight. The genotypes grouped in cluster III recorded strong dormancy both at 5 days and 10 days after harvesting whereas the genotypes of cluster IV recorded maximum grain yield/plant. Four polymorphic markers were used for genotyping of the RIL population and the lines viz.,SD 3, SD 12, SD 15, SD 68, SD 72, SD 87 and SD 113 which were categorized as strongly dormant upto 10 days after harvesting also exhibited similar banding pattern with the dormant parent MTU 1001 when amplified with more than two markers. Among the 119 RIL population studied, SD 12 manifested banding pattern as that of the dormant parent MTU 1001 with all the four polymorphic markers viz., RM346, RM22565, RM7051 and RM10793 under study and also exhibited <10% germination at 10 days after harvesting. The number of alleles detected for each of the 4 polymorphic markers ranged from 2 to 4 per loci with mean value of 2.75 alleles per locus. The dendrogram analysis divided the entire population into two distinct clusters at the distance of 2.25. The RILs viz., SD11, SD12, SD15, SD27, SD30, SD63, SD65, SD68, SD74, SD75, SD80 along with the dormant parent MTU 1001(SD 121) which recorded less than 50% germination and categorized as strongly dormant under phenotyping were grouped in cluster IB2 in molecular analysis thus revealing the similarity between the two methods.