1. National Center for Gene Research, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200233, China
2. State Key Laboratory of Systematic and Evolutionary Botany, Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
3. National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan