An Update on VitisGen: Recent Advances in Using DNA Marker Technologies in U.S. Grape Breeding Programs

The USDA-NIFA VitisGen project involves a multidisciplinary team of 25 co-PIs at 11 institutions aiming to optimize grape cultivar improvement. To this end, an impressive collection of phenotypic data and high-resolution genetic maps has been developed for seventeen F₁ families.  Here, we will present an update on a subset of our progress in adapting genotyping-by-sequencing (GBS) technology for highly heterozygous species, in the development of a Heterozygous Mapping Strategy (HetMappS) for GBS-based linkage mapping, and in the phenotyping and identification of QTL associated with diverse traits, ranging from fruit quality to pest resistance to vine morphology.  We will contrast different analytical approaches we have taken and provide a roadmap for application of GBS in heterozygous species.  Finally, we will discuss our experiences using other marker technologies for marker assisted selection.  The results we have obtained have the potential not only to accelerate grape cultivar improvement but also to enhance our genetic understanding of Vitis spp.