Mavrič Pleško I, Viršček Marn M, Žerjav M
Agricultural Institute of Slovenia, Hacquetova 17, SI-1000 Ljubljana, Slovenia.
Plant Dis. 2009 May;93(5):549. doi: 10.1094/PDIS-93-5-0549A.
Lettuce big-vein disease (LBVD) is an important disease of lettuce (Lactuca sativa L.) worldwide. Two viruses are reported to be associated with the disease, Lettuce big-vein associated virus (LBVaV) and Mirafiori lettuce big-vein virus (MLBVV). The majority of publications shows that MLBVV is the causal agent of LBVD, but two plants with big-vein symptoms and infected only with LBVaV were found by Roggero et al. (2). Lettuce plants with big-vein symptoms were observed in a greenhouse in Ljubljana and in a private garden near Sežana. Chlorotic vein banding with deformations of leaves were observed and the plants were generally smaller than those without symptoms. The seedlings at the first location were grown in sterilized soil and showed no such symptoms. Six symptomatic plants and two seedlings without symptoms from the first location and three symptomatic plants from the second location were analyzed for the presence of LBVaV and MLBVV. Total RNA was isolated from 50 mg of lettuce leaf tissue with a RNeasy plant mini kit (Qiagen, Chatsworth, CA). Multiplex reverse transcription-PCR with primers VP248 (5'-CGCCAGGATCTTTGATCCATCTG-3') and VP249 (5'-TTGCGACATGTTCCTCCTCATCG-3') for LBVaV, VP286 (5'-TATCAGCTCACATACTCCCTATCG-3') and VP287 (5'-CAACTAGCTCAGAATACATGCAG-3') for MLBVV, and VP383 and VP389 for internal control (1), was performed. Mixed infections with MLBVV and LBVaV were detected in four plants and only MLBVV was detected in two plants from the first location. None of the viruses was detected in the two seedlings without symptoms. Mixed infections with MLBVV and LBVaV were detected in all analyzed plants from the second location. According to these results, only MLBVV could be correlated with observation of disease symptoms. To our knowledge, this is the first reported association of MLBVV and LBVaV with big-vein disease in Slovenia. MLBVV was the only virus found in all samples with big-vein symptoms. References: (1) J. A. Navarro et al. Phytopathology 94:470. 2004. (2) P. Roggero et al. Eur. J. Plant Pathol. 109:261, 2003.
生菜大脉病（LBVD）是一种在全球范围内对生菜（Lactuca sativa L.）具有重要影响的病害。据报道，有两种病毒与该病相关，即生菜大脉相关病毒（LBVaV）和米拉菲奥里生菜大脉病毒（MLBVV）。大多数出版物表明，MLBVV是LBVD的致病因子，但罗杰罗等人（2）发现了两株出现大脉症状且仅感染LBVaV的植株。在卢布尔雅那的一个温室和塞扎纳附近的一个私人花园中观察到了有大脉症状的生菜植株。观察到叶片出现褪绿脉带并伴有变形，且这些植株通常比无症状的植株小。第一个地点的幼苗种植在无菌土壤中，未出现此类症状。对来自第一个地点的6株有症状植株、2株无症状幼苗以及来自第二个地点的3株有症状植株进行了LBVaV和MLBVV检测。使用RNeasy植物微量提取试剂盒（Qiagen，加利福尼亚州查茨沃思）从50毫克生菜叶片组织中提取总RNA。使用针对LBVaV的引物VP248（5'-CGCCAGGATCTTTGATCCATCTG-3'）和VP249（5'-TTGCGACATGTTCCTCCTCATCG-3'）、针对MLBVV的引物VP286（5'-TATCAGCTCACATACTCCCTATCG-3'）和VP287（5'-CAACTAGCTCAGAATACATGCAG-3'）以及用于内部对照的VP383和VP389进行多重逆转录PCR（1）。在第一个地点的4株植株中检测到MLBVV和LBVaV的混合感染，2株植株中仅检测到MLBVV。在2株无症状幼苗中未检测到任何病毒。在来自第二个地点的所有分析植株中均检测到MLBVV和LBVaV的混合感染。根据这些结果，只有MLBVV可能与病害症状的观察相关。据我们所知，这是斯洛文尼亚首次报道MLBVV和LBVaV与大脉病的关联。MLBVV是在所有有大脉症状的样本中发现的唯一病毒。参考文献：（1）J. A. 纳瓦罗等人。《植物病理学》94:470，2004年。（2）P. 罗杰罗等人。《欧洲植物病理学杂志》109:261，2003年。
