Genomic structure and ex situ conservation of the North American grapevine Vitis labrusca

Societal Impact Statement The North American wild grapevine species Vitis labrusca is an important source of disease resistance and climate resilience traits for breeding new grapevine cultivars. To ensure its continued use in breeding, V. labrusca must be accurately identified, and genetically diverse material must be conserved. We used genomics to examine both currently conserved and additional wild‐collected V. labrusca individuals. We found that many individuals labeled as V. labrusca are likely hybrids and that genetically distinct populations from Virginia and North Carolina are not conserved. By identifying genomic conservation gaps, our findings support more effective conservation strategies which will safeguard V. labrusca for future use in breeding. Summary Crop wild relatives, such as the North American grapevine Vitis labrusca , are valuable sources of disease resistance and climate resilience for breeding improved plant cultivars. To support their continued use in breeding both in situ (in natural habitat) and ex situ (off‐site) conservation is required. We assessed how well the United States Department of Agriculture (USDA) ex situ collection represents the genomic diversity of V. labrusca . We examined 314 accessions of V. labrusca , including accessions conserved in the USDA germplasm collection and wild‐collected accessions. Using genotyping‐by‐sequencing, we identified over 44,000 genetic markers which we used to determine population structure, potential mislabeling or hybridization, and the extent to which ex situ conserved accessions adequately capture this species. Approximately one third of the accessions examined in this study were identified as putative hybrids, highlighting the need for living germplasm collections given the high likelihood of hybrid seed. We also identified both geographic and genomic conservation gaps in conserved V. labrusca . Our results demonstrate the need for improved genetic validation of conserved grapevine germplasm as well as additional sampling to improve representation of wild V. labrusca conserved ex situ. We highlight geographic areas, particularly in Virginia and North Carolina, for additional collection efforts to help safeguard this important species for biodiversity conservation as well as future breeding and research efforts.