Use of expressed sequence tags-derived simple sequence repeat (SSR) markers for population studies of released and elite sweet potato

2018

English

Development of improved varieties of sweet potato to meet specific end users in the sub-SaharanAfrican region has the potential of transforming the crop’s market, consumption and health benefits.Molecular biology techniques such as fingerprinting are key to crop improvement, and critical fornumerous genetic studies. This study, carried out in Ghana, seeks to determine genetic relatednessamong two populations of sweet potato (released and elite), as well as to identify polymorphic andinformative markers for diversity studies. Twenty expressed sequence tags-simple sequence repeat(EST-SSR) markers were used for analysis of DNA assembled. A total of 169 alleles were obtained, withan average of 8.5 alleles per locus. Pairwise genetic distance among genotypes ranged from 12 – 89.GenAlex v6.4 analysis showed that a higher genetic diversity existed within elite genotypes than thereleased lines. Results analyzed using Popgene version 1.31 software indicated that on the basis ofboth populations studied, EST-SSR markers utilized were very polymorphic (95%) and showed geneticdiversity (I =0.888, He= 0.548) suggesting high heterozygosity in the collected varieties. The overall Fit(0.372%) and Fis (0.088%) suggest high genetic diversity within populations, and gene flow (1.95)indicate an exchange of genes between released sweet potatoes and elite ones. Ewens-Watterson testwas conducted to test the neutrality. From the results obtained, markers CB329940, CB330477 andCB330936 showed high allelic polymorphism among varieties used and were recommended to beincluded in diversity studies.

Quain, M. D.; Adofo, K.; Appiah-Kubi, D.; Akomeah, B.