[Tian, Jianxiang] Hunan Agr Univ, Coll Continuing Educ, Changsha 410128, Hunan, Peoples R China.
[Yang, Huilin] Hunan Agr Univ, Oriental Sci & Technol Coll, Changsha 410128, Hunan, Peoples R China.
[Xiang, Pingan] Hunan Agr Univ, Coll Business, Changsha 410128, Hunan, Peoples R China.
[Liu, Dengwang] Hunan Agr Univ, Upland Crop Res Inst, Changsha 410128, Hunan, Peoples R China.
[Li, Lin] Hunan Agr Univ, Coll Agron, Changsha 410128, Hunan, Peoples R China.