Distributions, ex situ conservation priorities, and genetic resources potential of crop wild relatives of sweeetpotato (Ipomoea batatas (L.) Lam. I. series Batatas)

Authors: KHOURY, COLIN - International Center For Tropical Agriculture (CIAT); HEIDER, BETTINA - International Potato Center; CASTANEDA-ALVAREZ, NORA - International Center For Tropical Agriculture (CIAT); ACHICANOY, HAROLD - International Center For Tropical Agriculture (CIAT); SOSA, CHRYSTIAN - International Center For Tropical Agriculture (CIAT); MILLER, RICHARD - Southeastern Louisiana University; SCOTLAND, ROBERT - University Of Oxford; WOOD, JOHN - University Of Oxford; ROSSEL, GENOVEVA - International Potato Center; ESERMAN, LAUREN - University Of Georgia; Jarret, Robert - Bob; YENCHO, G - North Carolina State University; BERNAU, VIVIAN - The Ohio State University; JUAREZ, HENRY - International Potato Center; SOTELO, STEVEN - International Center For Tropical Agriculture (CIAT); DE HAAN, STEF - International Potato Center; STRUIK, PAUL - Wageningen University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2015
Publication Date: 4/21/2015
Citation: Khoury, C.K., Heider, B., Castaneda-Alvarez, N.P., Achicanoy, H.A., Sosa, C.C., Miller, R.E., Scotland, R.W., Wood, J.R., Rossel, G., Eserman, L.A., Jarret, R.L., Yencho, G.C., Bernau, V., Juarez, H., Sotelo, S., De Haan, S., Struik, P.C. 2015. Distributions, ex situ conservation priorities, and genetic resources potential of crop wild relatives of sweeetpotato (Ipomoea batatas (L.) Lam. I. series Batatas). Frontiers in Plant Science. doi: 10.3389/fpls.2015.00251.

Interpretive Summary: A large number of species of morninglory (Ipomoea spp.) are related to the sweetpotato. The potential of these wild species to contribute to the improvement of sweetpotato in unknown. However, it is generally acknowledged that some of these species – especially those most closely to the sweetpotato – are a potential source of useful genes. At the present time, plant genebanks contain only a relatively few examples of these sweetpotato-related species that are available for research, from scattered locations. We used computer modeling with information acquired from various botanical garden herbaria and elsewhere to determine geographic locations where additional plant material of a variety of sweetpotato-related species might be expected to be found, and to prioritize the species of greatest interest and potential use in sweetpotato improvement.

Technical Abstract: Crop wild relatives (CWR) of sweetpotato [Ipomoea batatas (L.) Lam., I. series Batatas] have the potential to contribute to breeding objectives for this important root crop. Uncertainty in regard to species boundaries and their phylogenetic relationships, and the limited availability of germplasm with which to perform crosses has constrained their utilization. We compiled geographic occurrence data on relevant CWR and produced potential distribution models for the species. We then assessed the comprehensiveness of ex situ germplasm collections, contextualized these results with research and breeding priorities, and used ecogeographic information to identify species with the potential to contribute desirable agronomic traits. Sweetpotato CWR species richness is concentrated in Mesoamerica and in the extreme southeastern United States. Currently designated species differ among themselves and in comparison to the crop in their adaptations to temperature, precipitation, and edaphic characteristics and most species also show considerable intraspecific variation. With 79% of species identified as high priority for further collecting, we find that these genetic resources are highly under-represented in ex situ conservation systems and thus their availability to breeders and researchers is inadequate. We outline priorities for enhancing their conservation, and describe the further research needed to mobilize CWR genetic resources for crop breeding.