Genetic diversity of sweet corn inbred lines of public sectors in Thailand revealed by SSR markers

Abstract

The Thailand governmental institutes play important roles in genetic improvement of sweet corn in Thailand. We assessed the genetic diversity of 268 sweet corn inbreds from three major institutes (NCSRC-KU, CNFCRC, and KKU) and three commercial hybrids using 20 SSR markers. The markers detected 224 alleles in total, with an average of 11.2 alleles per locus. Overall gene diversity was relatively high, being 0.7. Allelic richness, gene diversity, and heterozygosity in the inbreds among the three institutes were comparable. However, the inbreds from KKU possessed the greatest number of unique alleles and rare alleles, albeit they showed the highest percentage of genetic impurity. Neighbor-joining, principal coordinate, and STRUCTURE analyses showed that the inbreds were genetically different. Our findings provide insight into the breeding gene pool and population structures of the sweet corn germplasm of the public sector in Thailand, enhancing efficiency of sweet corn germplasm utilization for developing new varieties.

Keywords:
Sweet corn; inbred; heterotic group; diversity; SSR marker