Nie Bihua, Singh Mathuresh, Sullivan Andrew, Singh Rudra P, Xie Conghua, Nie Xianzhou
Potato Research Centre, Agriculture and Agri-Food Canada (PRC-AAFC), Fredericton, New Brunswick E3B 4Z7, Canada, and National Center for Vegetable Improvement (Central China), MOE Key Laboratory of Horticultural Plant Biology, Hubei Provincial Research Center of Potato Engineering and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Agricultural Certification Services, New Brunswick E3B 8B7, Canada.
Plant Dis. 2011 Feb;95(2):113-119. doi: 10.1094/PDIS-04-10-0257.
A field isolate of Potato virus Y (PVY) was collected in New Brunswick, Canada in 2007 due to unusual symptoms observed on different potato cultivars. To unveil the PVY strain identity, tobacco and potato bioassays, PVY and PVY-specific antibody-based enzyme-linked immunosorbent assays, and reverse-transcription polymerase chain reaction (PCR)-based genotyping were carried out. All the assays demonstrated that the isolate, designated as PVY-FL in this study, belonged to the PVY strain group. Greenhouse tests with the potato cvs. FL 1533 and Jemseg confirmed the severe nature of infection by PVY-FL. The complete genome sequences of PVY-FL and PVY-RB, the latter a mild PVY isolate, were determined. BLAST analysis revealed that the two isolates shared 97 and 98% sequence identities at the nucleotide and polyprotein levels, respectively. Further BLAST analysis unveiled that PVY-FL shared 99.7% nucleotide sequence identity with PVY-Oz, an isolate reported in New York, United States, whereas the PVY-RB isolate shared 99.2% sequence identity with PVY-139, a PVY isolate reported in New Brunswick, Canada. A phylogenetic tree of available, full-length sequences of PVY isolates demonstrated two subgroups within the PVY branch, one clustered with PVY-RB and the other with PVY-FL. Group-specific sense primers for differentiation of the two subgroups were developed and evaluated. A limited survey of potato tubers collected from a field plot at the Potato Research Centre, Agriculture and Agri-Food Canada, using the newly developed PCR primers, indicated that 65.3 and 2.4% of the PVY-positive tubers were infected with PVY isolates belonging to the PVY-FL and PVY-RB subgroups, respectively. Assessment of the pathogenicity of three representative isolates from each subgroup on the potato cv. Jemseg demonstrated that severe and mild symptoms were induced by the PVY-FL-like and PVY-RB-like isolates, respectively.
2007年，在加拿大新不伦瑞克省，由于在不同马铃薯品种上观察到异常症状，采集了一株马铃薯Y病毒（PVY）田间分离株。为了确定PVY菌株的身份，进行了烟草和马铃薯生物测定、基于PVY和PVY特异性抗体的酶联免疫吸附测定以及基于逆转录聚合酶链反应（PCR）的基因分型。所有测定均表明，本研究中指定为PVY-FL的分离株属于PVY菌株组。用马铃薯品种FL 1533和Jemseg进行的温室试验证实了PVY-FL感染的严重性。测定了PVY-FL和PVY-RB（后者为温和的PVY分离株）的完整基因组序列。BLAST分析显示，这两个分离株在核苷酸和多蛋白水平上的序列同一性分别为97%和98%。进一步的BLAST分析表明，PVY-FL与美国纽约报道的一株分离株PVY-Oz的核苷酸序列同一性为99.7%，而PVY-RB分离株与加拿大新不伦瑞克报道的一株PVY分离株PVY-139的序列同一性为99.2%。PVY分离株全长序列的系统发育树显示，PVY分支内有两个亚组，一个与PVY-RB聚类，另一个与PVY-FL聚类。开发并评估了用于区分这两个亚组的组特异性正义引物。使用新开发的PCR引物对从加拿大农业和农业食品部马铃薯研究中心的一块田间地块采集的马铃薯块茎进行的有限调查表明，分别有65.3%和2.4%的PVY阳性块茎感染了属于PVY-FL和PVY-RB亚组的PVY分离株。对每个亚组的三个代表性分离株对马铃薯品种Jemseg的致病性评估表明，PVY-FL样和PVY-RB样分离株分别诱导了严重和轻微症状。
