Verhoeven J Th J, Botermans M, Roenhorst J W, Westerhof J, Meekes E T M
Plant Protection Service, P.O. Box 9102, 6700 HC Wageningen, the Netherlands.
Naktuinbouw, P.O. Box 40, 2370 AA Roelofarendsveen, the Netherlands.
Plant Dis. 2009 Mar;93(3):316. doi: 10.1094/PDIS-93-3-0316A.
Since the recent identification of Potato spindle tuber viroid (PSTVd) in vegetatively propagated ornamental plant species (4), many growers have asked to have their mother plants tested for this viroid. In December of 2007, a grower from Turkey submitted cuttings of cape gooseberry (Physalis peruviana) to be tested for PSTVd. Initial testing by real-time reverse transcription (RT)-PCR according to Boonham et al. (1) indicated the presence of either Mexican papita viroid, PSTVd, or Tomato chlorotic dwarf viroid in four samples. To identify the viroid(s) present, isolated RNA from these samples was used for RT-PCR (2), and products of the expected full genome size for the three viroids were amplified from each sample. One of the PCR products was sequenced (GenBank Accession No. EU862230) and analysis of the 357 nt sequence indicated it was most related to PSTVd sequences belonging to the so-called 'Oceanian' strain of the viroid (3), with 99.7% identity to GenBank Accession No. AY962324. Therefore, the viroid was identified as PSTVd. Pathogenicity of this PSTVd genotype was demonstrated when 4 weeks after mechanical inoculation with sap extracts seedlings of tomato cv. Money-maker showed the expected viroid symptoms of chlorosis and stunting, and the presence of the viroid in these plants was confirmed by RT-PCR (2). In March of 2008, by use of RT-PCR (2) and sequencing of the PCR product (GenBank Accession No. EU862231), PSTVd was identified in young seedlings of P. peruviana from a German grower. The German isolate differed at only three nucleotide positions from the Turkish isolate. The identification of PSTVd in young seedlings indicates that seeds had been source of infection, whereas in the case of the PSTVd infected cuttings from Turkey, the infection originated from infected mother plants. To our knowledge, these are the first reports of PSTVd in P. peruviana. Although infected P. peruviana plants did not show symptoms, they might act as sources of inoculum for crops like potato and tomato, which may suffer serious damage. References: (1) N. Boonham et al. J. Virol. Methods 116:139, 2004. (2) A. M. Shamloul et al. Can. J. Plant Pathol. 19:89, 1997. (3) J. Th. J. Verhoeven et al. Eur. J. Plant Pathol. 110:823, 2004. (4) J. Th. J. Verhoeven et al. Plant Pathol. 57:399, 2008.
自从最近在无性繁殖的观赏植物品种中鉴定出马铃薯纺锤块茎类病毒（PSTVd）以来（4），许多种植者要求对其母株进行该类病毒检测。2007年12月，一位来自土耳其的种植者提交了灯笼果（酸浆属酸浆）插条，用于检测PSTVd。根据Boonham等人（1）的方法，通过实时逆转录（RT）-PCR进行的初步检测表明，四个样品中存在墨西哥番木瓜类病毒、PSTVd或番茄褪绿矮缩类病毒。为了鉴定存在的类病毒，从这些样品中分离的RNA用于RT-PCR（2），并且从每个样品中扩增出了三种类病毒预期全基因组大小的产物。对其中一个PCR产物进行了测序（GenBank登录号EU862230），对357个核苷酸序列的分析表明，它与属于该类病毒所谓“大洋洲”株系的PSTVd序列关系最为密切（3），与GenBank登录号AY962324的序列同一性为99.7%。因此，该类病毒被鉴定为PSTVd。当用番茄品种“Money-maker”的汁液提取物机械接种4周后，幼苗出现了预期的类病毒症状，即黄化和矮化，并且通过RT-PCR（2）证实了这些植物中存在类病毒，从而证明了这种PSTVd基因型的致病性。2008年3月，通过RT-PCR（2）和对PCR产物进行测序（GenBank登录号EU862231），在一位德国种植者的酸浆属酸浆幼苗中鉴定出了PSTVd。德国分离株与土耳其分离株仅在三个核苷酸位置上有所不同。在幼苗中鉴定出PSTVd表明种子是感染源，而在土耳其受PSTVd感染的插条中，感染源自受感染的母株。据我们所知，这些是酸浆属酸浆中PSTVd的首次报道。虽然受感染的酸浆属酸浆植物没有表现出症状，但它们可能成为马铃薯和番茄等作物的接种源，而这些作物可能会遭受严重损害。参考文献：（1）N. Boonham等人，《病毒学方法杂志》116:139, 2004。（2）A. M. Shamloul等人，《加拿大植物病理学杂志》19:89, 1997。（3）J. Th. J. Verhoeven等人，《欧洲植物病理学杂志》110:823, 2004。（4）J. Th. J. Verhoeven等人，《植物病理学》57:399, 2008。
