Lance Cadle-Davidson, Bruce Reisch, Jason Londo, Anne Fennell, Matthew Clark, Craig Ledbetter, Gavin Sacks, Chin-Feng Hwang, Cheng Zou, Qi Sun, Ugochukwu Ikeogu, Dario Cantu, and Timothy Martinson*
*Cornell University, Cornell AgriTech, 635 West North Street, Geneva, NY, 14456 (tem2@cornell.edu)

In adapting to climate change, growers will need to cope with climate-induced chang­es in phenology, disease and pest complexes, and other stressors. While adapting cultural practices may mitigate climate-related challenges, breeding varieties that are more resilient to climate change will provide new solutions to long-standing weak­nesses in current cultivars: notably, extreme susceptibility of Vitis vinifera cultivars to powdery mildew (PM) and downy mildew (DM). The VitisGen2 project is a nationwide collaboration (USDA-Geneva, UC Davis, USDA-Parlier, Cornell University, Missouri State University, University of Minnesota, South Dakota State University, Washington State University, and North Dakota State University) to identify DNA marker-trait as­sociations and incorporate marker-assisted selection (MAS) into breeding programs. A novel genetic mapping platform (rhAmpSeq) that provides 2000 markers that are transferable across the Vitis genus has been used with 16 mapping populations in CA, NY, MO, and SD to identify >70 novel quantitative trait loci for PM and DM resistance, fruit quality traits (malate metabolism, anthocyanin acylation), and bloom phenol­ogy. Over the past eight years, the project has used MAS to screen over 60,000 grape seedlings from breeding programs in CA, MN, NY, ND, SD, AR, FL, and MO, and produced so-called “RenStack” breeding lines for researchers to access four to six PM resistance loci simultaneously for crossing. Abundant and affordable DNA sequence information is transforming grape breeding.

Funding Support: NIFA Specialty Crop Research Initiative Competitive Grant #2017- 51181-26829