1. State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
2. College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, P. R. China
3. College of Science, Huazhong Agricultural University, Wuhan 430070, P. R. China
4. College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, P. R. China