Classical breeding leading to grapevines resistant to Pierce's disease

Pierce's disease of grapes has been a persistent problem in some areas of California and, right now, it's on the upswing, reported Ester Mobley in the San Francisco Chronicle.

A UC Agriculture and Natural Resources researcher has been working for 15 years to develop Pierce's disease-resistant grapevines and he's read to unleash them into the world.

"Spraying to control for PD won't pass environmental muster," said Andy Walker, UC ANR viticulture geneticist and professor in the Department of Viticulture and Enology at UC Davis. "And GMOs are problematic. For us, the best way forward is through classical breeding."

The project is based on the identification several years ago of a single dominant gene in a Mexican grape species - Vitis arizonica - that promises to confer resistance to Pierce's disease. After making a series of cross breeds resulting in a vines that are 94 percent Vitis vinifera, Walker has developed vines that are similar to any Zinfandel or Sauvignon Blanc grapes, but will never get PD.

The writer reviewed the wines produced with Walker's research grapes and declared them impressive overall. 

For more on this research, see Breeding and genetics key to stemming Pierce's disease in UC ANR's California Agriculture journal.

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