1. First and fourth authors: USDA-ARS, Crop Improvement and Protection Research, Salinas, CA 93905; second author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414; Boyce Thompson Institute, Cornell University, Ithaca, NY 14853; and third author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414.