Crossability and Genetic Characterization of a North American Representative ofIpomoea grandifolia(Convolvulaceae), a Member ofIpomoeaSeriesBatatas

Species in the genusare often difficult to identify due to their similar morphologies and their ability to hybridize with one another. An undescribed North Americanmorphotype inseries, referred here asCarolina morphotype, was found to be morphologically, genetically, and reproductively isolated from other locally co-occurringspecies. A previous phylogenetic analysis that included a broader sampling of species inseriessuggested thatCarolina morphotype may be, a species described as found only in South America. To evaluate these findings, we tested intrinsic cross-compatibility betweenCarolina morphotype andas well as with three other co-localizing North Americanspecies:,, and. We also examined genetic differentiation using single nucleotide polymorphisms from leaf transcriptomes from multiple individuals of all five species and several outgroup species. We find no cross-incompatibility and little genetic differentiation betweenCarolina morphotype and, suggesting thatCarolina morphotype is a representative of. This finding raises additional questions about the origins ofin North America and how its disjunct distribution could play a role in the divergence ofin the future.

Duke Scholars

Author Mark D. Rausher Biology