Kirk W W, Gieck S L, Crosslin J M, Hamm P B
Department of Plant Pathology, Michigan State University, East Lansing 48824.
Oregon State University, Hermiston Agricultural Research and Extension Center (HAREC), Hermiston 97838.
Plant Dis. 2008 Mar;92(3):485. doi: 10.1094/PDIS-92-3-0485B.
Potato is the fourth most important agricultural commodity in Michigan and is grown for table stock, chip processing, and seed. Tubers are either processed or fresh packed immediately following harvest or sent to storage. Tubers of potato cv. FL1879 representing two separate fields in Huron County were removed from separate storage facilities in February and March of 2007, and substantial internal necrosis was observed in 1 to 2% of the tubers. Symptoms included arcs similar to those caused by Tobacco rattle virus (TRV). This virus is a member of the genus Tobravirus and is transmitted by a number of species of stubby-root nematodes (Paratrichodorus or Trichodorus spp.). Stubby-root nematodes have been reported previously from Michigan (1). To confirm the presence of TRV, nucleic acid extractions were made from these symptomatic tubers (3). Samples were initially tested for TRV by reverse transcription (RT)-PCR using primers specific to the 16 kDa open reading frame on genomic RNA-1 (2). Samples from both storage facilities were positive. The 463-bp RT-PCR product, amplified with these primers, was sequenced (GenBank Accession No. EU315227) and was 99.6% identical to the corresponding region of two TRV isolates from Florida and Washington (GenBank Accession Nos. AF055912 and EU315226, respectively). In addition, sap from cv. FL1879 tuber samples was used to transmit the virus mechanically to tobacco cv. Samsun NN, which produced typical TRV symptoms following inoculation, and sap extracts from the tobacco leaves also tested positive with antiserum specific to TRV upon subsequent ELISA testing. Corky ringspot can result in substantial losses, with entire potato fields being rejected because of internal tuber damage. Once found, fields must be considered permanently at risk to this disease due to the large host range of both the virus and the nematode vector. This disease has been previously found in the United States in California, Colorado, Florida, Idaho, Washington, Oregon, and it is likely present in Indiana. To our knowledge, this is the first report of corky ringspot and TRV on potato in Michigan. References: (1) G. W. Bird and N. Knobloch. Plant Dis. Rep. 60:76, 1976. (2) J. M. Crosslin and P. E. Thomas. Am. Potato J. 72:605, 1995. (3) G. G. Presting et al. Phytopathology 85:436, 1995.
土豆是密歇根州第四重要的农产品，种植目的包括供应市场、用于薯片加工以及作为种薯。块茎在收获后要么立即进行加工或新鲜包装，要么送去储存。2007年2月和3月，从休伦县两个不同田块收获的代表品种FL1879的土豆块茎，从不同的储存设施中取出，发现1%至2%的块茎出现了严重的内部坏死。症状包括类似烟草脆裂病毒（TRV）引起的弧形病斑。这种病毒属于烟草脆裂病毒属，由多种短根线虫（毛刺线虫属或剑线虫属）传播。此前在密歇根州已报道过短根线虫（1）。为了确认TRV的存在，从这些有症状的块茎中提取了核酸（3）。最初使用针对基因组RNA - 1上16 kDa开放阅读框的特异性引物，通过逆转录（RT）-PCR对样品进行TRV检测（2）。来自两个储存设施的样品均呈阳性。用这些引物扩增得到的463 bp RT - PCR产物进行了测序（GenBank登录号EU315227），与来自佛罗里达州和华盛顿州的两个TRV分离株的相应区域有99.6%的同一性（GenBank登录号分别为AF055912和EU315226）。此外，用品种FL1879块茎样品的汁液将病毒机械传播到烟草品种Samsun NN上，接种后产生了典型的TRV症状，后续ELISA检测时，烟草叶片的汁液提取物用TRV特异性抗血清检测也呈阳性。栓皮环斑病会导致重大损失，整个土豆田块可能因块茎内部受损而被拒收。一旦发现，由于病毒和线虫载体的寄主范围广泛，这些田块必须被视为永远有感染这种病害的风险。此前在美国的加利福尼亚州、科罗拉多州、佛罗里达州、爱达荷州、华盛顿州、俄勒冈州都发现过这种病害，印第安纳州可能也有。据我们所知，这是密歇根州土豆上栓皮环斑病和TRV的首次报道。参考文献：（1）G. W. Bird和N. Knobloch。植物病害报告60:76，1976。（2）J. M. Crosslin和P. E. Thomas。美国马铃薯杂志72:605，1995。（3）G. G. Presting等人。植物病理学85:436，1995。
