Unravelling genetic diversity and population structure of sweetpotato (Ipomoea batatas (L.) Lam) through microsatellite markers

Sweetpotato ( Ipomoea batatas (L.) Lam), a vital root crop cultivated globally by small and marginal farmers, plays a pivotal role in combatting malnutrition and serves as a lifeline for underdeveloped nations. In order to optimize the utilization of germplasm for breeding purposes, it is crucial to comprehend the extent of genetic diversity it encompasses. The effective utilization of genetic diversity in germplasm resources hinges on assessing genetic relationships among diverse cultivars and landraces, facilitating improved breeding programs and sustainable agricultural practices. In this study, 31 sweetpotato genotypes were examined to assess genetic diversity using 21 simple sequence repeat (SSR) markers. A total of 704 amplicons were detected, averaging 33.52 per marker. Band frequency ranged from 0.33 to 0.69, while polymorphic information content ranged from 0.03 to 0.61. Utilizing the Dice similarity coefficient, the 31 genotypes were clustered into three primary clusters, demonstrating similarity scores from 0.09 to 0.92. Subsequent subdivision of these clusters revealed nuanced relationships within the dataset. Population structure analysis uncovered two well-stratified subpopulations, Subpop1 and Subpop2, with Fst values of 0.49 and 0.23, respectively. Average distances within Subpop1 and Subpop2 were 0.26 and 0.33, and the estimated allele-frequency divergence was 0.21. The SSR markers utilized in this study proved to be informative and polymorphic, offering insights into the genetic diversity of sweetpotato. These markers hold significant potential for enhancing breeding programs aimed at improving elite progenies in the future.