Assessment of Phenotypic and Genotypic Diversity in Elite Temperate and Tropical Sweet Sorghum Cultivars

Sweet sorghum is one of the many types of cultivated sorghums and is a promising multipurpose biofuel feedstock. The objective of this study was to assess phenotypic and genotypic diversity among 75 selected diverse sweet sorghum genotypes available at ICRISAT-Patancheru. Genotyping-by-sequencing generated 135,162 SNPs having minor allele frequencies > 0.20. Cluster analysis grouped the genotypes into three distinct clusters, with some of the sweet sorghum lines falling in distinct clusters. This grouping pattern was in conformity with available race and pedigree information. Mean performance and analysis of variance for sugar yield-related traits shows considerable variability. The results also revealed close genetic relationships between elite genotypes such as ICSV 25316, ICSV 25311, SSV 74 and ICSV 25300 that are superior for various sugar yield-associated traits like plant height, biomass, juice yield and sugar content. Not surprisingly given their pedigrees, these elite materials grouped together tightly in a single sub-cluster.