Nono-Womdim R, Swai I S, Chadha M L, Gebre-Selassie K, Marchoux G
AVRDC Africa Regional Program, P.O. Box 10, Duluti, Arusha, Tanzania.
INRA Station de Pathologie Vegetale, B.P. 94 84143 Montfavet Cedex, France.
Plant Dis. 2001 Jul;85(7):801. doi: 10.1094/PDIS.2001.85.7.801A.
African eggplant, or garden egg (Solanum aethiopicum) is an important vegetable in most sub-Saharan African countries. Since June 1997, viral symptoms, including mosaic, vein clearing, and stunting, have been observed on several crops of African eggplant cv. Tengeru White at a number of sites in the Arusha region of northern Tanzania. Field inspections revealed disease incidence ranging from 50 to 90%. During the same period, high populations of the green peach aphid Myzus persicae were observed in affected crops of African eggplant. These aphids were also found to reproduce in African eggplants. Flexuous, rodshaped virus-like particles, approximately 750 nm long and 12 nm wide, were found in electron microscope leaf dips from field samples of naturally affected African eggplants. The particle size suggested a species of Potyviridae. Thus, 20 field-infected samples of S. aethiopicum (randomly collected from four farms) were assayed in double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) for the presence of Potato virus Y (PVY) and Pepper veinal mottle virus (PVMV), known to infect tomato and other solanaceous crops in the region (2). However, all samples gave negative results. Further DAS-ELISA were performed with the same extracts from naturally infected plants of S. aethiopicum with antisera directed against Tobacco etch virus, Tobacco vein mottling virus, Pepper mottle virus, and Chilli veinal mottle virus (ChiVMV). All 20 samples were positive only for ChiVMV. ChiVMV, a single-stranded RNA virus transmitted in a nonpersistent manner by several aphid species, is one of the most important viruses of pepper in Asia (1). To confirm DAS-ELISA results, an isolate of ChiVMV from African eggplant was transmitted by mechanical inoculations, resulting in disease on tobacco (Nicotiana tobacco cv. Xanthi nc), pepper (Capsicum annuum cv. Yolo Wonder), tomato (Lycopersicon esculentum cv. Tengeru 97), and African eggplant (S. aethiopicum cv. Tengeru White). Extracts from the inoculated plants tested positive for the presence of ChiVMV in DAS-ELISA. This mechanically transmitted isolate did not infect melon (Cucumis melo), cucumber (C. sativus), or cowpea (Vigna unguiculata), which are nonhosts of ChiVMV. To our knowledge, this is the first report of the natural occurrence of ChiVMV in African eggplant. References: (1) S. K. Green et al. PETRIA 9:332, 1999. (2) R. Nono-Womdim et al. J. S. Afr. Soc. Hort. Sci. 6:41-44, 1996.
非洲茄子，即园艺茄子（埃塞俄比亚茄），是撒哈拉以南非洲大多数国家的一种重要蔬菜。自1997年6月以来，在坦桑尼亚北部阿鲁沙地区的多个地点，几种非洲茄子品种“滕格鲁白”的作物上出现了病毒症状，包括花叶、叶脉失绿和植株矮化。田间检查发现发病率在50%至90%之间。同一时期，在受影响的非洲茄子作物中观察到大量桃蚜。这些蚜虫也在非洲茄子上繁殖。在自然感染的非洲茄子田间样本的电子显微镜叶浸片中发现了弯曲的、杆状的类病毒颗粒，长约750纳米，宽12纳米。颗粒大小表明是一种马铃薯Y病毒科的病毒。因此，对20份埃塞俄比亚茄田间感染样本（从四个农场随机采集）进行了双抗体夹心酶联免疫吸附测定（DAS - ELISA），检测是否存在马铃薯Y病毒（PVY）和辣椒脉斑驳病毒（PVMV），已知这两种病毒会感染该地区的番茄和其他茄科作物（2）。然而，所有样本结果均为阴性。用埃塞俄比亚茄自然感染植株的相同提取物，针对烟草蚀纹病毒、烟草脉斑驳病毒、辣椒斑驳病毒和辣椒脉斑驳病毒（ChiVMV）的抗血清进行了进一步的DAS - ELISA检测。所有20个样本仅对ChiVMV呈阳性。ChiVMV是一种单链RNA病毒，可由多种蚜虫以非持久性方式传播，是亚洲辣椒最重要的病毒之一（1）。为了确认DAS - ELISA结果，通过机械接种传播了一株来自非洲茄子的ChiVMV分离株，结果在烟草（烟草品种“Xanthi nc”）、辣椒（辣椒品种“Yolo Wonder”）、番茄（番茄品种“滕格鲁97”）和非洲茄子（埃塞俄比亚茄品种“滕格鲁白”）上引发了病害。接种植株的提取物在DAS - ELISA检测中呈ChiVMV阳性。这种机械传播的分离株未感染甜瓜（甜瓜）、黄瓜（黄瓜）或豇豆（豇豆），它们是ChiVMV的非寄主植物。据我们所知，这是ChiVMV在非洲茄子上自然发生的首次报道。参考文献：（1）S. K. Green等人，《PETRIA》9:332，1999年。（2）R. Nono - Womdim等人，《南非园艺科学杂志》6:41 - 44，1996年。
