Endemic wild potato (Solanum spp.) biodiversity status in Bolivia: Reasons for conservation concerns

Crop wild relatives possess important traits, therefore ex situ and in situ conservation efforts are essential to maintain sufficient options for crop improvement. Bolivia is a centre of wild relative diversity for several crops, among them potato, which is an important staple worldwide and the principal food crop in this country. Despite their relevance for plant breeding, limited knowledge exists about their in situ conservation status. We used Geographic Information Systems (GIS) and distribution modelling with the software Maxent to better understand geographic patterns of endemic wild potato diversity in Bolivia. In combination with threat layers, we assessed the conservation status of all endemic species, 21 in total. We prioritised areas for in situ conservation by using complementary reserve selection and excluded 25% of the most-threatened collection sites because costs to implement conservation measures at those locations may be too high compared to other areas. Some 70% (15 of 21 species) has a preliminary vulnerable status or worse according to IUCN red list distribution criteria. Our results show that four of these species would require special conservation attention because they were only observed in <15 locations and are highly threatened by human accessibility, fires and livestock pressure. Although highest species richness occurs in south-central Bolivia, in the departments Santa Cruz and Chuquisaca, the first priority area for in situ conservation according to our reserve selection exercise is central Bolivia, Cochabamba; this area is less threatened than the potato wild relatives’ hotspot in south-central Bolivia. Only seven of the 21 species were observed in protected areas. To improve coverage of potato wild relatives’ distribution by protected areas, we recommend starting inventories in parks and reserves with high modelled diversity. Finally, to improve ex situ conservation, we targeted areas for germplasm collection of species with <5 accessions conserved in genebanks.