Principal component analysis and clustering of proso millet genotypes based on SSR marker diversity

Abstract

The current study mainly aims the assessment of the principal component analysis, genetic divergence and molecular diversity studies in proso millet accessions. The conservation and utilization of plant genetic resources require the identification and characterization of germplasm. Molecular markers are commonly utilized to evaluate genetic and taxonomic association, diversity among population structure in various species. In principal component analysis, out of 15 PC components only five components were significant (to assess maximum diversity) and these five components contributed over 78.04% of total phenotypic variance. The PC1 showed positive loading values and maximum variation explaining in the traits plant height, number of basal tillers, flag leaf blade width, flag leaf blade length, peduncle length, panicle length, number of grains per panicle and number of primary inflorescence branches. Seed color shows the highest Shannon-Weaver diversity index (1.306) among all the germplasm accessions followed by leaf pubescence (0.692), growth habit (0.690), inflorescence shape (0.684) and sheath pubescence (0.604). Totally 9 alleles were amplified by 4 polymorphic markers among 24 SSR primers studied. Alleles marked by primers with a range of 2 to 3 alleles and mean of 2.25 alleles per locus. The PIC values of primers ranged from 0.45 (Pm7689) to 0.71 (Pm564). In this study three polymorphic primers exhibited PIC values of more than 0.5. In NTSYS software grouped the 72 proso millet accessions into seven major clusters by using UPGMA clustering method (Table 5). Cluster VI is the largest one which had 19 accessions followed by cluster I (18) and cluster III (18). The similarity coefficient ranges 0.11 to 0.88. lesser similarity coefficient accessions possessed higher genetic variation and hybridization of these accessions may result in desirable recombinants and more advantageous in breeding programs.