1. College of Plant Protection, China Agricultural University, Beijing 100193, P. R. China
2. Guizhou Tobacco Company, Zunyi Branch, Zunyi 563000, P. R. China
3. Yunnan Tobacco Company, Yuxi Branch, Yuxi 653100, P. R. China
4. State Key Laboratory of Chemical Resource Engineering, Beijing Lab of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, P. R. China