Genomic structure and ex situ conservation of the North American grapevine <em>Vitis labrusca</em>

<p><em>Vitis labrusca</em>, a North American wild grapevine, is an important source of disease resistance and climate resilience traits for grape breeding, yet its genomic diversity is incompletely represented in ex situ germplasm collections. We genotyped 314 accessions, which included material conserved at the USDA germplasm collection and newly sampled wild individuals. Accessions were genotyped using genotyping-by-sequencing, and after imputation and filtering, we identified a total of 44,701 SNPs. Within the accessions genotyped, we identified extensive mislabelling and hybridization, with approximately one-third of accessions classified as putative hybrids. We also detected genetically distinct populations from Virginia and North Carolina that are not currently conserved. These results reveal significant geographic and genomic gaps in <em>ex situ</em> conservation of <em>V. labrusca</em> and highlight priority regions for future sampling to better safeguard this species for breeding and research.</p>