Pappu H R, Bertrand P F, Moore J M
Department of Plant Pathology.
Department of Crop and Soil Sciences, University of Georgia, Coastal Plain Experiment Station, Tifton 31793.
Plant Dis. 2000 Sep;84(9):1047. doi: 10.1094/PDIS.2000.84.9.1047C.
During the 2000 growing season, tobacco plants showing blotching of the leaves with light and dark green areas suggestive of Tobacco mosaic virus (TMV) infection were observed in several counties in Georgia. Symptomatic plants appeared in the field within 4 weeks after transplanting. The incidence in individual fields was as high as 100%. A survey was conducted in several tobacco-growing counties, and the presence of TMV was verified by enzyme-linked immunosorbent assay (ELISA). Symptomatic plants were collected from the following 20 counties: Appling, Bacon, Berrien, Coffee, Colquitt, Cook, Echols, Evans, Grady, Irwin, Jeff Davis, Lanier, Lowndes, Montgomery, Pierce, Tattnall, Tift, Toombs, Ware, and Wayne. Of the 79 samples tested by ELISA, TMV was found to be present in 76 samples. This high degree of incidence of TMV in Georgia's tobacco has not been observed in the past. Although the specific reasons are not clear, all severe cases of TMV were observed in two varieties, NC71 and NC72, or plants of other varieties out of beds or plant houses that held these two varieties and were clipped with the same mower. While TMV and Potato virus Y (PVY) were found most prevalent in Georgia's flue-cured tobacco in 1999 (2), none of the plants tested were positive for PVY in 2000. Cucumber mosaic virus was reported to be more common in Florida during the last 3 years (1). The severe outbreak of TMV highlights the importance of preventive measures such as observing sound sanitation practices. References: (1) T. A. Kucharek et al. Plant Dis. 82:1172, 1998; (2) H. R. Pappu et al. Plant Dis. 84:201, 2000.
在2000年生长季节，在佐治亚州的几个县观察到烟草植株叶片出现斑驳，有淡绿色和深绿色区域，提示感染了烟草花叶病毒（TMV）。有症状的植株在移栽后4周内出现在田间。个别田块的发病率高达100%。在几个烟草种植县进行了一项调查，并通过酶联免疫吸附测定（ELISA）证实了TMV的存在。从以下20个县采集了有症状的植株：阿普林、培根、贝里恩、咖啡、科尔奎特、库克、埃科尔斯、埃文斯、格雷迪、欧文、杰斐逊·戴维斯、拉尼尔、洛恩兹、蒙哥马利、皮尔斯、塔特纳尔、蒂夫特、图姆斯、韦尔和韦恩。在通过ELISA检测的79个样本中，发现76个样本中存在TMV。佐治亚州烟草中TMV如此高的发病率在过去未曾见过。虽然具体原因尚不清楚，但所有严重的TMV病例都出现在两个品种，即NC71和NC72，或其他品种的植株中，这些植株来自曾种植这两个品种且用同一台割草机修剪过的苗床或温室。虽然TMV和马铃薯Y病毒（PVY）在1999年的佐治亚州烤烟中最为普遍（2），但2000年检测的植株中没有一株PVY呈阳性。据报道，黄瓜花叶病毒在过去3年中在佛罗里达州更为常见（1）。TMV的严重爆发凸显了诸如遵守良好卫生规范等预防措施的重要性。参考文献：（1）T.A.库查雷克等人，《植物病害》82:1172，1998年；（2）H.R.帕普等人，《植物病害》84:201，2000年。
