1. Beijing Key Laboratory of Development and Quality Control of Ornamental Crops Department of Ornamental Horticulture College of Horticulture China Agricultural University Beijing 100193 China
2. Robert W. Holley Center for Agriculture and Health United States Department of Agriculture Agricultural Research Service Ithaca 14853 NY USA
3. Boyce Thompson Institute Ithaca14853 NY USA
4. Crops Pathology and Genetic Research Unit United States Department of Agriculture Agricultural Research Service Davis 95616 CA USA
5. Department of Plant Sciences University of California at Davis Davis 95616 CA USA