1. National Key Laboratory of Crop Genetic Improvement; Huazhong Agricultural University; Wuhan 430075 China
2. Division of Plant & Soil Sciences; West Virginia University; Morgantown WV 26506 USA
3. College of Resources & Environment; Huazhong Agricultural University; Wuhan 430075 China
4. Plant Biology Division; the Samuel Roberts Noble Foundation; Ardmore OK 73401 USA