Col ege of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, P.R.China;
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China;
Col ege of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, P.R.China;
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China;