VitisGen: A Coordinated Effort in Grape Genotyping, Phenotyping, and Marker Assisted Breeding

Grape cultivar improvement is complicated by long generation times, large plant size, and perennial infrastructure required.  To enable early selection of elite seedlings combining disease resistance, stress tolerance, and fruit quality, U.S. grape breeders and geneticists developed a coordinated strategy for marker discovery and application using centralized phenotyping and map development via genotyping-by-sequencing (GBS).  In this new project called VitisGen, over 5000 breeding lines will be genotyped each year to track alleles introgressed from eleven Vitis species.  Our current GBS pipeline results in the mapping of 20,000 SNPs per population, including alleles not present in the V. vinifera reference genome.   These dense genetic maps combined with the centralized phenotyping approach will lead to the development of at least 30 marker sets for alleles controlling traits of current and future interest for public grape breeding programs.  We will discuss our current strategies for the project and will welcome additional suggestions to maximize the impact of what is to become an unprecedented level of mapping data in specialty crops.