Abstract

A panel of 115 upland rice accessions of Assam was genotyped by using 45 SSR markers associated with major grain yield QTLs reported under drought stress. A total of 120 alleles were detected and the overall size of amplified products ranged from 60 to 500 bp. The number of alleles per loci varied from 2 to 4 with an average of 2.66 alleles per locus. The PIC values of markers ranged from 0.022 to 0.679 with an average value of 0.43. Low heterozygosity was observed among the cultivars with the average value of 0.083. The accessions were mainly grouped into two major clusters using different statistical method and software programmes. Population structure analysis revealed two major subgroups-SG 1 consisting of 44 accessions including drought susceptible check (Ranjit) and SG 2 consisting of 49 accessions including drought tolerant check (Nagina 22). The remaining 22 accessions were retained as admixture. The principal co-ordinates analysis revealed that first two coordinates explained the maximum variation of 18.06 and 5.5%, respectively. The AMOVA analysis revealed 20% of the molecular variation existed among population, 13% within individual, while 67% of variation was observed among the individuals. Lack of equilibrium among the groups was indicated by high FIT value of 0.873.