The wild relatives of grape in China: Diversity, conservation gaps and impact of climate change

China is one of the major diversity centres of grape (Vitis spp.) and is therefore one of the most abundant sources of Vitis germplasm in the world. Grape wild relative species (GWRs) represent a potentially important source of valuable traits for the improvement of cultivated grape varieties and have significant characters for resistance to biotic and abiotic stress factors. We studied the ecogeographic diversity of GWRs, conservation gaps and impact of climate change on GWRs in China, based on a wide range of distribution data sourced from germplasm and herbarium specimens, field surveys and other literature. Results show that there are 39 species, 1 subspecies and 14 varieties of GWRs native to China and that 19 species and 9 varieties are the closest wild relatives to cultivated grape according to the Taxon Group Concept. GWRs are distributed in nearly all provinces in China except for Xinjiang, but they are particularly abundant in Jiangxi and Hunan provinces. The richest regions for GWRs are the Qinling, Daba, Wuling, Nanling and Wuyi mountains. Around 22% of GWR species are found in natural reserves (NRs) and are well protected, but 15 species are not found in NRs and require further strengthening of both protection and collection. The potential distribution of GWRs at the present and predicted future climate was compared using BIOCLIM. The results showed that simulated current distributions matched actual distribution ranges. Under the future climate scenario with doubled CO₂ concentration, suitable areas for continued survival of 21 GWRs could be reduced. Our results will therefore be extremely valuable for the development of a complementary conservation strategy for Vitis in China.