XVI International Botanical Congess

Phylogenetic relationships of Ipomoea section Eriospermum and four species representing four other sections of Ipomoea were investigated using ITS DNA sequences. The phylogenetic trees based on parsimony, likelihood and neighbor-joining were congruent and supported by high bootstrap estimates. The results were in good agreement with current taxonomy of the group, showing that I. umbraticola was most distantly related to sweet potato in the series Batatas, I. leucantha was closely associated with I. cordatotriloba and I. grandifolia, and I. cynanchifolia was closely related to I. triloba and I. tiliacea. Although ITS data lack sufficient variation to elucidate the precise origin of sweet potato, they can be used to identify its close relatives and to resolve relationships in sectional circumscription of Ipomoea.