Genetic diversity and population structure of Colombian sweet potato genotypes reveal possible adaptations to specific environmental conditions

AbstractIpomoea batatas, commonly known as sweet potato, is a widely cultivated and consumed crop. It is valued for its storage roots, which serve as an important source of energy and essential nutrients. However, in Colombia, sweet potato remains underutilized, with limited cultivation and consumption. Native and alternative crops are central to government strategies that link biodiversity to food security and sovereignty. This study evaluates the diversity and genetic structure of 438 genotypes from the Colombian Sweet Potato Collection (CSPC), using both morphological and molecular data, and proposes a core collection to support conservation strategies. Additionally, a genetic comparison with the USDA collection was conducted to contextualize the diversity of the CSPC within a global framework. Substantial diversity was observed among Colombian sweet potato genotypes. Four distinct phenotypic groups were identified based on their origin in the Andean and Caribbean regions, exhibiting variations in their ability to develop storage roots and floral structures under the conditions of the evaluation site. Molecular analyses revealed over 37,000 single nucleotide polymorphism (SNP) variants, allowing the identification of six genetic groups associated with geographic origin (Andean and Caribbean regions), altitude, levels of genetic diversity, and cultivation status (landraces, breeding lines, or wilds). A core collection of 100 genotypes was proposed to represent the genetic diversity of the CSPC, incorporating both morphological and molecular data. Finally, the CSPC was compared with the USDA collection, revealing clear genetic differentiation between the two collections and higher levels of genetic diversity in the CSPC. These findings highlight the broad genetic diversity of sweet potato in Colombia, with its genetic structure strongly influenced by local environmental conditions. They also confirm that Colombia is an important center of diversity for this crop. These insights are essential for advancing research, strengthening conservation efforts, and optimizing the use of sweet potato genetic resources in the country.