Genetic diversity evaluation and selection methods of sweet potato hybrid F1 population based on SSR markers and phenotypic detection

Sweet potato (Ipomoea batatas (L.) Lam.) is a vital global crop, with breeding focused on both high starch and high yield. Hybrid populations are crucial for genetic improvement, but research on sweet potato hybrid F₁ populations remains limited. To explore the genetic laws of important traits in hybrid progenies, this study investigates the genetic diversity and efficient selection methods of the hybrid F₁ population from crossing between Yushu No.12 (high starch content) and Luoxushu No.9 (high yield) using phenotypic detection and SSR markers. Coefficients of variation, genetic distances, and similarity coefficients results showed that the F₁ population has rich genetic diversity. The parents and F₁ progenies could be clustered into 4 and 6 categories based on phenotypic detection and SSR markers, respectively. The results of transgressive inheritance analysis and cluster analysis showed that the hybrid F₁ population of sweet potato was closer to the female parent and might exhibit matroclinous inheritance. Based on the principal component analysis (PCA) results, a comprehensive scoring model was developed to select superior progeny. Correlation analysis revealed a strong link (r = 0.6420) between the hardness and starch content of storage root, suggesting hardness could be used for rapid screening high-starch materials. Mantel test showed SSR markers as more reliable for evaluating genetic diversity than phenotypic analysis. These findings uncover the genetic diversity information of sweet potato F₁ generation, and provide strategies for the rapid and accurate selection of hybrid progenies, and lay theoretical foundation for deciphering the genetic mechanisms of important traits in sweet potato.