Distributions, ex situ conservation priorities, and genetic resource potential of crop wild relatives of sweetpotato [Ipomoea batatas (L.) Lam., I. series Batatas]

Abstract

Crop wild relatives 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, the limited availability of germplasm with which to perform crosses, and the difficulty of introgression of genes from wild species has constrained their utilization. Here, we compile geographic occurrence data on relevant sweetpotato wild relatives and produce potential distribution models for the species. We then assess the comprehensiveness of ex situ germplasm collections, contextualize these results with research and breeding priorities, and use ecogeographic information to identify species with the potential to contribute desirable agronomic traits. The fourteen species that are considered the closest wild relatives of sweetpotato generally occur from the central United States to Argentina, with richness 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 crop genetic resources are highly under-represented in ex situ conservation systems and thus their availability to breeders and researchers is inadequate. We prioritize taxa and specific geographic locations for further collecting in order to improve the completeness of germplasm collections. In concert with enhanced conservation of sweetpotato wild relatives, further taxonomic research, characterization and evaluation of germplasm, and improving the techniques to overcome barriers to introgression with wild species are needed in order to mobilize these genetic resources for crop breeding.

Climatic adaptation and ecological descriptors of wild beans from Mexico

“…Eco‐geographical analysis can differentiate collection sites and determine the ranges of adaptation for a species, facilitating collection strategies and supporting in situ conservation (Castañeda‐Álvarez et al., 2016; Khoury et al., 2015; López‐Soto, Ruiz‐Corral, Sánchez‐González, & Lépiz‐Ildefonso, 2005). Agroecological characterization of wild/cultivated niches helps to determine the environmental requirements of a species, providing information on the adaptability and degree of tolerance to specific ecological conditions (Maxted, Dulloo, & Ford‐Lloyd, 2016; Pliscoff & Fuentes‐Castillo, 2011; Svenning, Fløjgaard, Marske, Nógues‐Bravo, & Normand, 2011; Wang et al., 2009).…”

Analyse des connaissances endogènes et des déterminants de la production de la patate douce [<i>Ipomoea batatas</i> (L.)], une culture à haute valeur socioculturelle et économique au Bénin

“…Dans l'industrie, les tubercules servent à la production d'amidon (Triqui et al, 2009), de carburant, d'alcool et d'acide acétique (Romuald et al, 2013. La production mondiale annuelle des tubercules de patate douce est estimée à 104 millions de tonnes et la culture se fait dans 114 pays à travers le monde (FAO, 2013 ;Khoury et al, 2015). En Afrique, la production est estimée à 20 millions de tonnes ; elle est de 62000 tonnes au Bénin (FAO, 2013).…”

“…Ceci représente des atouts majeurs pour faire face au défi de la sécurité alimentaire dans le contexte des changements climatiques (Glato et al, 2014). En Afrique Sub-sahérienne, la culture de la patate se fait en général, sur de petites superficies plus ou moins fertiles avec peu d'intrants et aboutit à des rendements relativement bon (Khoury et al, 2015).…”

Priorities for enhancing the ex situ conservation and use of Australian crop wild relatives

“…Table S1. List of closely and distantly related crop wild relatives of major and minor food crops, identified as native to or naturalized in Australia (Wiersema et al 2012, Vincent et al 2013, The Harlan and de Wet Crop Wild Relative Inventory 2017, USDA NPGS Genetic Resources Information Network 2017), with gap analysis assessment results reported for close relatives and other species of high potential value for breeding of major food crops (Khoury et al 2015a, Khoury et al 2015b, and novel updated assessments following the same methodology). Potential distribution models assessment scores: ATAUC = five-fold average area under the ROC curve of test data, STAUC = standard deviation of the test AUC of the five different folds, ASD15 = proportion of the potential distribution model ensemble with standard deviation above 0.15.…”

“…We performed a detailed ex situ conservation gap analysis on the 58 native or naturalized Australian taxa that are either close relatives of major food crops (defined as being members of the primary or secondary genepools of such crops), or have been explicitly listed in publications describing confirmed or specific potential uses in plant breeding of these crops, indicating their relatively high potential value as genetic resources (Supplementary Table 1) (Wiersema et al 2012, Vincent et al 2013, Khoury et al 2015a, 2015b, The Harlan and de Wet Crop Wild Relative Inventory 2017, USDA NPGS Genetic Resources Information Network 2017). These include Australian native relatives of banana, eggplant, melon, mung bean, pigeonpea, rice, sorghum, soybean, sweetpotato and yam; and naturalized relatives of asparagus, Brassica crops, lettuce, plum, safflower, sugar beet, sweetpotato and watermelon.…”