Detection and analysis of main tobacco viruses and viruliferous plants in Shaanxi Province

【Objective】 This research aimed to identify the main types of tobacco viruses and detect plants carrying viruses in area surrounding tobacco fields at main tobacco growing areas in Shaanxi Province.【Method】 167 tobacco leaf samples with viral disease symptoms and 279 samples of 23 species plants that belonged to 7 families collected from tobacco fields in Ankang,Baoji,Yan'an,Shangluo,Tongchuang,Xianyang,and Hanzhong were tested by enzyme-linked immunosorbent assay(ELISA).【Result】 Tobacco mosaic virus(TMV),cucumber mosaic virus(CMV),tobacco etch virus(TEV),potato virus Y(PVY),and tobacco vein banding mosaic virus(TVBMV)were detected in infected tobacco leaf samples.The infection percentage(74.34%)of CMV was the highest,and that of PVY,TMV,TEV and TVBMV were 58.16%,47.29%,21.59% and 18.87%,respectively.Of the 156 positive tobacco leaf samples,28 cases were infected by CMV(4.78%),TMV(10.09%),PVY(1.66%)and TVBMV(1.18%).Other positive tobacco leaf samples infected by two or more viruses accounted for 82.05 %.Among the 279 samples of plants from areas surrounding tobacco fields,176 cases were detected with TMV,CMV and PVY,the virus detection rate was 63.08%.Cephalanoplos(Cirsium seputum)had the highest virus detection rate(92.83%),and that of tomato(Solanum lycopersicum),eggplant(Solanum melongena),peppers(Capsicum frutescens),and broad bean(Vicia faba)were 90.91%,87.50%,86.67%,and 78.57%,respectively.【Conclusion】 CMV had replaced TMV and TEV as the dominating virus in some tobacco-growing areas in Shaanxi Province,and the infection of PVY increased obviously in some regions.It is highly notable that mixed-virus infections occurred severely in tobacco fields.The plants from areas surrounding tobacco fields should be considered as an important factor to prevent tobacco virus disease.