1. Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture-Agricultural Research Service, Cornell University, Ithaca, New York 14853
2. College of Horticulture, Hebei Agricultural University, Baoding, Hebei 071001, China
3. State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, Shandong Agricultural University, Tai'an, Shandong 271018, China
4. Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853
5. Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China
6. Biotechnology Department, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt
7. University of Freiburg, Faculty of Biology II, 79104 Freiburg, Germany
8. Horticulture Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853