Tang J, Clover G R G, Alexander B J R, Quinn B D
Plant Health and Environment Laboratory, MAF Biosecurity New Zealand, P.O. Box 2095, Auckland 1140, New Zealand.
Plant Dis. 2008 Mar;92(3):486. doi: 10.1094/PDIS-92-3-0486C.
Passiflora latent virus (PLV) naturally infects cultivated and wild Passiflora species in Australia, Germany, Israel and the United States (1-3). In March 2004, chlorotic lesions were observed on leaves of three vines of Passiflora tarminiana on one site in Auckland, New Zealand. Chenopodium amaranticolor and C. quinoa inoculated with sap from symptomatic leaves developed chlorotic local spots, followed by systemic leaf chlorosis and necrosis. Local symptoms appeared more quickly on C. quinoa (12 days) than on C. amaranticolor (20 days). No symptoms were observed on inoculated plants of Nicotiana benthamiana, N. clevelandii, N. occidentalis, N. tabacum, or Phaseolus vulgaris. Electron microscopy of crude sap preparations from infected C. quinoa, C. amaranticolor, N. occidentalis, and P. tarminiana showed flexuous, filamentous virus particles approximately 650 nm long. Plants of P. tarminiana and the three inoculated indicator species containing virus particles tested positive by PLV polyclonal antiserum in double-antibody sandwich (DAS)-ELISA (DSMZ, Braunschweig, Germany) and immunosorbent electron microscopy (Stephan Winter, DSMZ, personal communication). Nucleic acid was extracted from leaves of plants of each of the four viruliferous species with an RNeasy Plant Mini Kit (Qiagen, Doncaster, Australia) and then used in reverse transcription (RT)-PCR tests with novel forward (5'-CGAGACACACGCAAACGAA-3') and reverse (5'-CAGCAAAGCAAAGACACGA-3') primers specific to a 523-bp fragment of the PLV polyprotein. PCR products of the expected size were obtained, and an amplicon from P. tarminiana was directly sequenced (GenBank Accession No. EU257510). A BLAST search in GenBank showed 94% nucleotide sequence identity with a PLV isolate from Israel (GenBank Accession No. DQ455582). To our knowledge, this is the first finding of PLV in P. tarminiana and the first report of the virus in New Zealand. Chenopodium spp. have been reported previously as experimental hosts (2,3), and this study revealed that N. occidentalis also can be infected latently with PLV. P. tarminiana is a weed in New Zealand and subject to active control measures to manage the species. Economically important species such as P. edulis and P. ligularis are potentially susceptible to the virus. These species are not grown commercially in the surrounding area but are common in domestic Auckland gardens. Infected vines were removed from the site and destroyed, and symptomatic vines have not been observed at other sites. References: (1) R. D. Pares et al. Plant Dis. 81:348, 1997. (2) S. Spiegel et al. Arch. Virol. 152:181, 2007. (3) A. A. Stihll et al. Plant Dis. 76:843, 1992.
西番莲潜隐病毒（PLV）在澳大利亚、德国、以色列和美国自然感染栽培和野生的西番莲属植物（1 - 3）。2004年3月，在新西兰奥克兰的一个地点，在三株塔明西番莲（Passiflora tarminiana）藤蔓的叶片上观察到褪绿斑。用有症状叶片的汁液接种苋色藜（Chenopodium amaranticolor）和藜（C. quinoa）后，出现了褪绿局部斑点，随后是全株叶片褪绿和坏死。藜上的局部症状出现得比苋色藜更快（12天比苋色藜的20天）。在接种的本氏烟草（Nicotiana benthamiana）、克利夫兰烟草（N. clevelandii）、西方烟草（N. occidentalis）、烟草（N. tabacum）或菜豆（Phaseolus vulgaris）植株上未观察到症状。对感染的藜、苋色藜、西方烟草和塔明西番莲的粗汁液制剂进行电子显微镜观察，显示出弯曲的丝状病毒粒子，长约650纳米。塔明西番莲植株以及含有病毒粒子的三种接种指示植物通过PLV多克隆抗血清在双抗体夹心（DAS）-ELISA（德国不伦瑞克的德国微生物和细胞培养物保藏中心）和免疫吸附电子显微镜检测（德国不伦瑞克的德国微生物和细胞培养物保藏中心的Stephan Winter，个人交流）呈阳性。用RNeasy植物小提试剂盒（澳大利亚唐卡斯特的Qiagen公司）从这四种带毒植物的叶片中提取核酸，然后用于逆转录（RT）-PCR检测，使用针对PLV多聚蛋白523碱基片段的新型正向引物（5'-CGAGACACACGCAAACGAA-3'）和反向引物（5'-CAGCAAAGCAAAGACACGA-3'）。获得了预期大小的PCR产物，并且对塔明西番莲中的一个扩增子进行了直接测序（GenBank登录号EU257510）。在GenBank中进行的BLAST搜索显示，与来自以色列的一个PLV分离株（GenBank登录号DQ455582）的核苷酸序列同一性为94%。据我们所知，这是PLV在塔明西番莲中的首次发现，也是该病毒在新西兰的首次报道。先前已报道藜属植物为实验寄主（2,3）。并且本研究表明西方烟草也可被PLV潜伏感染。塔明西番莲在新西兰是一种杂草，并且受到积极的控制措施以管理该物种。像食用西番莲（P. edulis）和具舌西番莲（P. ligularis）等具有经济重要性的物种可能对该病毒易感。这些物种在周边地区没有商业化种植，但在奥克兰家庭花园中很常见。已从该地点移除并销毁了受感染的藤蔓，并且在其他地点未观察到有症状的藤蔓。参考文献：（1）R. D. Pares等人，《植物病害》81:348，1997年。（2）S. Spiegel等人，《病毒学档案》152:181，2007年。（3）A. A. Stihll等人，《植物病害》76:843，1992年。
