Genetic diversity of sugar beet genotypes evaluated by microsatellite DNA markers

Aim: Identification of diverse sugar beet (Beta vulgaris L.) genotypes is essential for using them as parents in sugar beet improvement programme of India. Hence, genetic variation and diversity of elite sugar beet germplasm collection was analysed using microsatellite markers. Methodology: Genomic DNA of thirteen genotypes was amplified using 14 microsatellite primers containing dinucleotide to compound repeat motifs. Amplified bands were scored on gel, transformed into a binary character matrix and analyzed through NTSYS software for clustering in heterotic groups. Identification of genetically diverse genotypes Results: A total of 243 amplicons were resolved and grouped into 88 alleles of distinct molecular weight ranging from 124 to 1222 bp with an average of 17.36 amplicons/primer, 4 to10 alleles/SSR locus and moderate to high PIC ranging from 0.625-0.851. Similarity coefficients (SM) based on the presence/absence of alleles ranged from 0.47 to 0.89 (mean value of 0.65). UPGMA dendrogram based on SM, grouped these genotypes in two major taxonomical groups with five clusters having one, four, three, three and two genotypes each. Clustering pattern of UPGMA matched with the 2D and 3D scatter plots of MDS and RCA. The highly significant cophenetic coefficient of r = 0.96 proved that these SSR markers efficiently analyzed the genetic relationships of sugar beet genotypes. Interpretation: Microsatellite markers can be used as a potential cost effective method for exploring molecular genetic diversity in sugar beet in order to obtain new genetic combinations.