Larsen R C, Myers J R
USDA, ARS, Prosser WA 99350, E-mail: <
Oregon State University, Corvallis 97331.
Plant Dis. 1998 Sep;82(9):1064. doi: 10.1094/PDIS.1998.82.9.1064A.
Lentil (Lens culinaris Medik.) is an important legume crop grown in the dryland Pacific Northwest areas of eastern Washington and Oregon, and northern Idaho. Lentil is highly susceptible to pea enation mosaic enamovirus (PEMV) and bean leafroll luteovirus (BLRV), and infection may result in severe yield losses. Recently, lentil was also found to be infected experimentally with red clover vein mosaic carlavirus (RCVMV) (1). The virus is most commonly transmitted in the Pacific Northwest by the pea aphid (Acyrthosiphon pisum Harris) in a nonpersistent manner. In 1997, cv. Brewer lentil bait plants were planted at the Vegetable Research Farm at Oregon State University to monitor incidence of PEMV and BLRV. Many of the plants developed symptoms typical of PEMV. However, other plants exhibited severe stunting, proliferation of axillary branches, and general chlorosis or death. Bait plants were harvested in August, and 204 random samples were tested for PEMV, RCVMV, BLRV, alfalfa mosaic alfamovirus (AMV), and pea streak carlavirus (PeSV) by standard enzyme-linked immunosorbent assay (ELISA) protocols. Antiserum for RCVMV was made in the Prosser lab against an isolate from chickpea collected in Washington State (1). RCVMV was detected in 76 (34%) of the 204 samples. PEMV, AMV, BLRV, and PeSV were detected in 197 (89.5%), 23 (11.3%), 2 (0.9%), and 0 (0%) of samples, respectively. Results showed that 75/76 of the samples positive for RCVMV were also coinfected with PEMV. Plants infected with RCVMV in the greenhouse also produced mild systemic mosaic symptoms in selected hosts inoculated mechanically, including pea (Pisum sativum L.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.), and lentil. Lentil and chickpea also showed moderate to severe stunting. Chlorotic local lesions were formed on Chenopodium amaranticolor Coste & Reyn. and C. quinoa Willd. Oligonucleotide primers were designed with sequence data obtained from the Washington isolate of RCVMV (1), and identification of the virus was verified in pea and lentil by polymerase chain reaction (PCR). Primer design of RCV34V and RCV653C targeted a 619-bp fragment located in the viral coat protein gene. Plants testing positive by ELISA yielded PCR products of the expected size when visualized on agarose gels. This is the first report of natural infection of lentil by RCVMV. Reference: (1) R. C. Larsen et al. Phytopathology 87:S56, 1997.
小扁豆（Lens culinaris Medik.）是一种重要的豆类作物，种植于华盛顿州东部、俄勒冈州以及爱达荷州北部的太平洋西北地区旱地。小扁豆对豌豆耳突花叶病毒（PEMV）和菜豆卷叶黄化病毒（BLRV）高度敏感，感染这些病毒可能会导致严重的产量损失。最近，还发现小扁豆在实验中感染了红三叶草脉花叶病毒（RCVMV）（1）。该病毒在太平洋西北地区最常见的传播方式是由豌豆蚜（Acyrthosiphon pisum Harris）以非持久性方式传播。1997年，在俄勒冈州立大学蔬菜研究农场种植了“布鲁尔”小扁豆诱饵植株，以监测PEMV和BLRV的发病率。许多植株出现了PEMV典型症状。然而，其他植株表现出严重矮化、腋芽增殖以及普遍黄化或死亡。诱饵植株于8月收获，通过标准酶联免疫吸附测定（ELISA）方法对204个随机样本进行了PEMV、RCVMV、BLRV、苜蓿花叶病毒（AMV）和豌豆线条病毒（PeSV）检测。针对RCVMV的抗血清是在普罗瑟实验室利用从华盛顿州收集的鹰嘴豆分离株制备的（1）。在204个样本中的76个（34%）检测到了RCVMV。在样本中分别检测到PEMV、AMV、BLRV和PeSV的比例为197个（89.5%）、23个（11.3%）、2个（0.9%）和0个（0%）。结果显示，在76个RCVMV检测呈阳性的样本中，有75个同时感染了PEMV。在温室中感染RCVMV的植株在机械接种的选定寄主中也产生了轻度系统花叶症状，这些寄主包括豌豆（Pisum sativum L.）、鹰嘴豆（Cicer arietinum L.）、蚕豆（Vicia faba L.）和小扁豆。小扁豆和鹰嘴豆还表现出中度至重度矮化。在苋色藜（Chenopodium amaranticolor Coste & Reyn.）和藜（C. quinoa Willd.）上形成了褪绿局部病斑。利用从RCVMV华盛顿分离株获得的序列数据设计了寡核苷酸引物（1），并通过聚合酶链反应（PCR）在豌豆和小扁豆中验证了病毒的鉴定。RCV34V和RCV653C引物设计靶向病毒外壳蛋白基因中一个619 bp的片段。通过ELISA检测呈阳性的植株在琼脂糖凝胶上可视化时产生了预期大小的PCR产物。这是关于小扁豆自然感染RCVMV的首次报道。参考文献：（1）R. C. Larsen等人。植物病理学87:S56，1997。
