Genetic diversity analysis of geographically diverse landraces and wild accessions in sorghum

Landraces are highly dynamic populations with historical origins. Several factors have influenced the evolution of landraces and some of them were selection by farmers, natural selection, gene-flow from various neighboring populations, genetic drifts, etc. In this study, we phenotyped 36 landraces and wild populations of sorghum conserved at ICRISAT genebank, Hyderabad, India, to assess the diversity among the populations of sorghum. Since landraces are diverse populations, we phenotyped more plants (over 100 plants) in each accession for nine economically important quantitative traits, thus capturing the entire variability. Our study revealed that the clustering pattern based on D2 statistics grouped the 36 accessions into 5 clusters, in which cluster 1 holds the maximum number of 15 accessions and cluster 3 with the least (2 accessions). Minimal intra cluster distance (3.66) was observed in cluster 3 followed by cluster 5 (9.52), while the maximum intra cluster distance was found in cluster 2 (12.50). The highest inter cluster distance was found between clusters 1 and 4 (16.29) indicating the presence of wide diversity between accessions of these two clusters. Accessions in cluster 1 were early maturing (67 days after sowing, DAS) while those in cluster 4 were late maturing (129 DAS) and high yielding (36.9 g). Results from this study provide information about the diversity of landraces and wild sorghum populations for their utilization in crop improvement