Zotto A Dal, Ortego J M, Raigón J M, Caloggero S, Rossini M, Ducasse D A
Institute of Plant Pathology and Plant Physiology (IFFIVE-CICVyA) National Institute of Agriculture Technology (INTA), Cno. 60 Cuadras Km 51/2, Cordoba (X5020ICA) Argentina.
EEA Junín INTA, I. Busquet s/n, 5572 Junín, Mendoza, Argentina.
Plant Dis. 2006 Apr;90(4):523. doi: 10.1094/PD-90-0523C.
Sharka disease, caused by Plum pox virus (PPV), is probably the most important disease of stone fruits crops worldwide because of tremendous yield losses from infected trees (1). During November 2004, symptoms resembling sharka disease were observed in a plum and apricot orchard consisting of 5,000 trees in Pocito, San Juan Province, Argentina. Apricot leaves showed chlorotic spots while plum leaves showed chlorotic rings, spots, and irregular edges. Plum fruits were deformed and much smaller than those from symptomless trees. Samples collected from 70 symptomatic trees were tested using double-antibody sandwich enzyme-linked immunosorbent assays with a polyclonal antiserum anti-PPV from BIOREBA (Reinach BL1, Switzerland), and immunosorbent electron microscopy with a polyclonal antiserum from our laboratory made against a recombinant PPV capsid protein (CP). The samples were also tested using double-antibody sandwich indirect enzyme-linked immunosorbent assay using the REAL kit (Durviz, Valencia, Spain) with two different monoclonal antibodies including Mab 5b that recognizes all strains of PPV and Mab 4DG5 that is specific for PPV strain D. Samples were positive with both antibodies in 80% of the cases. Leaf extracts from symptomatic plum samples were also analyzed by immuno-capture reverse-transcription polymerase chain reaction. A 1,209-bp fragment was amplified with specific primers that anneal at the 5' end of the coat protein coding region and the viral 3' end poly A tail. The amplified fragment was cloned and the nucleotide sequence was determined for two of the resulting clones (Gen-Bank Accession Nos. DQ299537 and DQ299538). The sequences were 98% identical with the PPV-strain D from the United States (GenBank Accession No. AF360579) and Germany (GenBank Accession No. X81081). The restriction sites for AluI and RsaI, previously described (2) as typical for the PPV-D strain, were present in the expected positions. To our knowledge, this is the first report of PPV-D in Argentina. Reference: (1) M. Németh. Virus, Mycoplasma, and Rickettsia Disease of Fruit Trees. Martinus Nijhoff Publishers, Dordrecht, the Netherlands, 1986. (2) T. Wetzel et al. J. Virol. Methods 33:355, 1991.
李痘病由李痘病毒（PPV）引起，可能是全球核果类作物最重要的病害，因为受感染树木会造成巨大的产量损失（1）。2004年11月，在阿根廷圣胡安省波西托一个有5000棵树的李树和杏树果园中，发现了类似李痘病的症状。杏树叶出现褪绿斑点，而李树叶出现褪绿环、斑点和不规则边缘。李果实变形，比无症状树木的果实小得多。从70棵有症状的树上采集的样本，使用来自BIOREBA（瑞士赖纳赫BL1）的抗PPV多克隆抗血清进行双抗体夹心酶联免疫吸附测定，并使用我们实验室制备的针对重组PPV衣壳蛋白（CP）的多克隆抗血清进行免疫吸附电子显微镜检测。样本还使用REAL试剂盒（西班牙巴伦西亚的Durviz公司）进行双抗体夹心间接酶联免疫吸附测定，该试剂盒含有两种不同的单克隆抗体，包括识别所有PPV毒株的Mab 5b和对PPV-D毒株特异的Mab 4DG5。在80%的病例中，样本对两种抗体均呈阳性。对有症状李样本的叶提取物也进行了免疫捕获逆转录聚合酶链反应分析。用在外壳蛋白编码区5'端和病毒3'端多聚A尾退火的特异性引物扩增出一个1209bp的片段。扩增片段被克隆，并对两个所得克隆测定了核苷酸序列（Gen-Bank登录号：DQ299537和DQ299538）。这些序列与来自美国（GenBank登录号：AF360579）和德国（GenBank登录号：X81081）的PPV-D毒株有98%的同一性。先前描述的（2）作为PPV-D毒株典型特征的AluI和RsaI限制性酶切位点，出现在预期位置。据我们所知，这是PPV-D在阿根廷的首次报道。参考文献：（1）M. Németh。《果树的病毒、支原体和立克次氏体病害》。Martinus Nijhoff出版社，荷兰多德雷赫特，1986年。（2）T. Wetzel等人。《病毒学方法杂志》33:355，1991年。
