Estimating genetic diversity in Sorghum bicolor using molecular markers

Abstract

Aim: The present study aimed at measuring the genetic diversity of a set of 219 sorghum accessions differing in their grain colour. Methodology: About 219 diverse sorghum lines differing in their grain colour were obtained from National Bureau of Plant Genetics Resources (NBPGR), New Delhi and genotyped using 17 SSR markers. Polymorphism information content (PIC) and allele frequency were determined using PowerMarker V3.25. Clustering and factorial analysis were performed using DARwin 6.0. GenAlex version 6.5 was used to perform Principal Coordinates Analysis (PCoA) and AMOVA. Diversity analysis was performed by using Darwin. Results: Genotyping of 219 sorghum accessions using 17 SSR markers produced a total of 399 alleles with an average PIC value of 0.85 and gene diversity of 0.87. Highest allele frequency was observed for the marker, Xtxp 265 whereas highest major allele frequency was observed in 196 accessions for the marker, Xtxp 278. Diversity analysis divided the 219 accessions into three clusters (1, 2 and 3) and genotypes belonging to same geographical origin were found to be clustered together. Interpretation: SSR marker based genetic diversity analysis grouped 219 sorghum accessions into three clusters. Grouping and clustering of accessions was mostly based on the geographical origins with some exceptions which may be due to cross hybridisation of accessions between countries paving a way for cross gene flow.