The U.S. Department of Agriculture (USDA) has just awarded the project an additional $2.5 million to continue this research. With matching funds from the grape industry, VitisGen's budget now tops $9 million -- an unusually large size for specialty crop research.
The five-year VitisGen molecular research project, launched in 2011 with an initial $2.1 million grant from the USDA's National Institute of Food and Agriculture Specialty Crop Research Initiative (SCRI), is a collaboration among 25 scientists from 12 institutions, including all of the nation's public grape breeding programs. Their primary goal is to map unique snippets of DNA in the grape genome -- called markers -- to certain traits, such as cold-hardiness, fruit weight and disease resistance. Once these marker-trait linkages are found across 18 different grape-breeding populations, breeders can use them to streamline hybrid selection and ultimately the release of new grape varieties.
"Grape breeding is mainly an evaluation process to figure out which new variety is best. This is where DNA markers come in. If grape breeders can use markers to screen out 95 percent of their seedlings in the first few weeks, focusing on evaluating only the top five to 10 percent of their hybrid crosses, those that really have promise, it would be a huge efficiency," said Reisch.
In their first year, VitisGen researchers have made substantial progress, largely due to the speed and processing power of next-generation DNA sequencing technology. They created molecular maps of grape chromosomes in 6,000 varieties -- triple their original goal. Also, all U.S. public grape breeding programs now have access to DNA marker technology, which has allowed VitisGen researchers to begin helping grape breeders apply a few known trait markers to their programs.
"We've had a great deal of success in our first year and a lot of enthusiasm from breeders," said Lance Cadle-Davidson, project co-leader and plant pathologist with the USDA's Agricultural Research Service.
VitisGen will also increase breeder efficiency by helping them select goals of most interest to the industry and consumers. To do this, VitisGen sociologists and economists are conducting surveys to identify the grape traits that form an "overlapping consensus": matching what consumers want, what scientists can do, and what is economical and beneficial for growers.
"If breeders know which traits are important enough to consumers that it makes sense for them to spend time on them versus others, this will significantly reduce the amount of time and resources needed to evaluate new crosses," said Hans Walter-Peterson, viticulture extension specialist at Cornell Cooperative Extension and VitisGen's extension and outreach lead.
As VitisGen moves forward, Reisch said breeders can use trait markers to more efficiently develop varieties with multiple genes for natural disease resistance, making their effects more sustainable and longer lasting. The result is higher quality fruit with less pesticide use -- something increasingly desired by growers and consumers.
"This project creates a recipe for success to get the best varieties on the market that have all the favorable traits of interest. Grapevine species have so much genetic variation to tap into, there are so many varieties and flavors out there. It could be much more exciting for grape growers and consumers as tasters," said Reisch.