เชื้อไวรัสใบด่าง (สายพันธุ์ ยู1) wa

เชื้อไวรัสใบด่าง (สายพันธุ์ ยู1) was obtained from the Key Laboratory of Tobacco Chemistry,Yunnan Academy of TobaccoS cience.The virus was reproduced in N. tabacum cv. K326 and purified by method in literature (Gooding and Hebert, 1967). The purified virus was kept at 20 8C. The half-leaf method (Hu et al., 2013) was used on Nicotiana glutinosa cultivated in aninsect free greenhouse.The irus mix edwiththetestcom pound was in oculated on theleftside of a leaf, whereas the virus mixed with the solvent as a negative control was inoculated on the right side of the leaf, and Ningnanmycin was used as positive control. The local lesion numbers were recorded three to four days after inoculation. Three leaf blades were used for each compound. The inhibition rates were calculated by inhibition rate (%) = [(CT)/ C] 100%. C is the average number of local lesions in the control and T is the average number of local lesions in the treated leaves.