The Study of Genetic Diversity of Cassava (Manihot esculenta) Using SSR Markers

Abstract

Genetic research and development of cassava in Thailand have been limited due to insufficient information on genetic diversity of cassava varieties. This research aimed to investigate the genetic diversity and to analyze cluster of 18 cassava varieties collected at Rayong Field Crops Research Center, Department of Agriculture using SSR markers. It was conducted during October 2017 – September 2018. Results showed that 54 of 60 SSR markers used in this study were able to amplify DNA fragments from all varieties and generated polymorphic allele in total of 265 alleles varying from 1 – 8 allele per locus, with an average of 4.82 alleles per locus of which 263 alleles showed the polymorphic bands with the percentage of 97.27%. Sizes of DNA fragments ranged from 85 – 597 base pairs. The Polymorphism Information Content (PIC) value ranged from 0.00 – 0.36, with an average of 0.24. Cluster analysis based on UPGMA and genetic relationships using NTSYSpc version 2.10 program showed similarity coefficient value ranging from 0.119 – 0.615, revealed two distinct groups, with cophenetic correlation (r) of 0.87, suggesting clear clustering. Therefore, SSR markers in this study were appropriate to identify the genetic differences and to select cassava varieties for breeding