Wegener L A, Punja Z K, Martin R R
Department of Biological Sciences, Simon Fraser University, Burnaby, BC Canada.
USDA-ARS Horticultural Crops Research Laboratory, Corvallis, OR 97331.
Plant Dis. 2007 Mar;91(3):328. doi: 10.1094/PDIS-91-3-0328C.
Blueberry scorch virus (BlScV), an aphid-borne carlavirus, causes a serious disease of highbush blueberry (Vaccinium corymbosum L.) in North America and Europe. Symptoms of BlScV infection on highbush blueberry include necrosis of flower blossoms and young leaves, shoot blight, and chlorosis. Currently, cranberry (Vaccinium macrocarpon L.) is the only other natural host of BlScV. In July 2004, wild black huckleberry (Vaccinium membranaceumL.) was sampled in the Kootenay Region of southeastern British Columbia. Foliar tissues were sampled during 2004 from 11 bushes from a clearing on the side of a mountain near Crawford Bay, BC, Canada and tested by double-antibody sandwich-ELISA using polyclonal antiserum (Agdia Inc., Elkhart, IN). BlScV was detected in 6 of the 11 bushes sampled and in the positive control (BlScV-infected blueberry leaf tissue) and was not detected in the negative control (healthy blueberry leaf tissue). To confirm the presence of the virus, total nucleic acid was extracted from ELISA-positive huckleberry samples according to an established protocol (A. Rowhani et al. Proc. Int. Counc. Stud. Viruses Virus-Like Dis. Grapevine, Extended Abstr. 13:148, 2000). Reverse transcription-PCR was performed using pd(T) random primer (Amersham Biosciences, Piscataway, NJ) for reverse transcription and BlScV-specific primers developed against the published NJ-2 sequence of BlScV (GenBank Accession No. NC_003499). Using the forward primer, BS708F, (5'-TCAATCCGTGGTGCTACGAG-3'), and the reverse primer, BS1188R, (5'-ACAGTGCGCAATGTTCCAGT-3'), a 480-bp amplicon was obtained from each of the ELISA-positive samples, while no ampli-cons were observed for the negative control (ELISA-negative huckleberry tissue). Direct sequencing of one selected amplicon revealed 90, 84, and 77% nucleotide sequence identity and 97, 96, and 88% amino acid sequence identity with strains NJ-2, BC-1 (GenBank Accession No. AY941198) and BC-2 (GenBank Accession Nos. AY941199), respectively. BlScV-infected huckleberries were asymptomatic. The presence of BlScV in alternate hosts has implications for disease epidemiology. Testing for BlScV in Vaccinium species in and around commercial highbush blueberry plantings, as well as lowbush blueberry (V. angustifolium Aiton), rabbiteye blueberry (V. ashei Reade), other native Pacific Northwest species (V. ovatum Pursh and V. parvifolium Smith), and ornamental Vaccinium species is warranted. To our knowledge, this is the first report of BlScV infecting black huckleberry.
蓝莓焦枯病毒（BlScV）是一种由蚜虫传播的香石竹潜隐病毒属病毒，在北美和欧洲引发了高丛蓝莓（Vaccinium corymbosum L.）的一种严重病害。高丛蓝莓感染BlScV的症状包括花朵和幼叶坏死、嫩枝枯萎以及黄化。目前，蔓越莓（Vaccinium macrocarpon L.）是BlScV的唯一其他天然寄主。2004年7月，在不列颠哥伦比亚省东南部的库特奈地区采集了野生黑果越橘（Vaccinium membranaceumL.）样本。2004年期间，从加拿大不列颠哥伦比亚省克劳福德湾附近一座山旁空地上的11株灌木上采集了叶片组织，并使用多克隆抗血清（Agdia公司，印第安纳州埃尔克哈特）通过双抗体夹心酶联免疫吸附测定（ELISA）进行检测。在采集的11株灌木中的6株以及阳性对照（感染BlScV的蓝莓叶片组织）中检测到了BlScV，而在阴性对照（健康蓝莓叶片组织）中未检测到。为了确认病毒的存在，根据既定方案（A. 罗哈尼等人，《国际葡萄病毒及类似病毒病害研究理事会会议论文集》，扩展摘要13:148，2000年）从ELISA阳性的越橘样本中提取了总核酸。使用pd(T)随机引物（安玛西亚生物科学公司，新泽西州皮斯卡塔韦）进行反转录，并使用针对已公布的BlScV NJ - 2序列（GenBank登录号NC_003499）设计的BlScV特异性引物进行反转录 - 聚合酶链反应（RT - PCR）。使用正向引物BS708F（5'-TCAATCCGTGGTGCTACGAG-3'）和反向引物BS1188R（5'-ACAGTGCGCAATGTTCCAGT-3'），从每个ELISA阳性样本中获得了一个480 bp的扩增子，而阴性对照（ELISA阴性的越橘组织）未观察到扩增子。对一个选定的扩增子进行直接测序显示，其与NJ - 2、BC - 1（GenBank登录号AY941198）和BC - 2（GenBank登录号AY941199）菌株的核苷酸序列同一性分别为90%、84%和77%，氨基酸序列同一性分别为97%、96%和88%。感染BlScV的越橘没有症状。BlScV在替代寄主中的存在对疾病流行病学有影响。有必要对商业高丛蓝莓种植区及其周边的越橘属物种，以及矮丛蓝莓（V. angustifolium Aiton）、兔眼蓝莓（V. ashei Reade）、太平洋西北部其他本土物种（V. ovatum Pursh和V. parvifolium Smith）和观赏性越橘属物种进行BlScV检测。据我们所知，这是BlScV感染黑果越橘的首次报道。
