Gurung Suraj, Short Dylan P G, Hu Xiaoping, Sandoya German V, Hayes Ryan J, Koike Steven T, Subbarao Krishna V
Department of Plant Pathology, University of California, Davis, c/o U.S. Agricultural Research Station, Salinas 93905.
State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
Plant Dis. 2015 Jul;99(7):933-938. doi: 10.1094/PDIS-12-14-1307-RE. Epub 2015 May 22.
Verticillium is a genus that includes major vascular wilt pathogens. Recently, multilocus phylogenetic analyses of the genus identified five new species, including Verticillium isaacii and V. klebahnii, both of which occur in agricultural soils in coastal California and have been isolated from asymptomatic and diseased spinach and lettuce plants. Little data are available regarding their pathogenicity and virulence on a broader range of crops important to the region. Four isolates each of V. isaacii and V. klebahnii along with two reference isolates of V. dahliae races 1 and 2 were inoculated on eight crops (artichoke, cauliflower, eggplant, lettuce, pepper, tomato, spinach, and strawberry) in a greenhouse experiment. After 8 weeks, plants were assessed for disease severity to determine the relative host ranges of Verticillium isolates. Additionally, 13 lettuce lines resistant to race 1 and partially resistant to race 2 of V. dahliae were screened against V. isaacii and V. klebahnii to evaluate their responses. Three of four V. isaacii and four of four V. klebahnii isolates tested were nonpathogenic on all crops tested except those indicated below. One V. isaacii isolate caused wilt on artichoke and 'Salinas' lettuce and most isolates of both species caused varying degrees of Verticillium wilt on strawberry. Lettuce lines resistant to V. dahliae race 1 and partially resistant to V. dahliae race 2 also exhibited resistance to all of the isolates of V. isaacii and V. klebahnii. Thus, at least some isolates in the populations of V. isaacii and V. klebahnii have the potential to become significant pathogens of coastal California crops. However, resistance developed against V. dahliae also offers resistance to the pathogenic isolates of both species, at least in lettuce.
轮枝菌属是一个包含主要维管束萎蔫病原菌的属。最近，对该属进行的多位点系统发育分析确定了五个新物种，包括艾氏轮枝菌和克莱巴轮枝菌，这两种菌都出现在加利福尼亚沿海的农业土壤中，并且已从无症状和患病的菠菜及生菜植株中分离出来。关于它们对该地区更广泛的重要作物的致病性和毒力的数据很少。在温室试验中，将艾氏轮枝菌和克莱巴轮枝菌的四个分离株分别与大丽轮枝菌1号和2号生理小种的两个参考分离株接种在八种作物（菊芋、花椰菜、茄子、生菜、辣椒、番茄、菠菜和草莓）上。8周后，评估植株的病情严重程度，以确定轮枝菌分离株的相对寄主范围。此外，对13个对大丽轮枝菌1号生理小种有抗性且对大丽轮枝菌2号生理小种部分抗性的生菜品系进行了针对艾氏轮枝菌和克莱巴轮枝菌的筛选，以评估它们的反应。除了下文指出的作物外，所测试的四个艾氏轮枝菌分离株中的三个以及四个克莱巴轮枝菌分离株中的四个对所有测试作物均无致病性。一个艾氏轮枝菌分离株在菊芋和“萨利纳斯”生菜上引起萎蔫，并且这两个物种的大多数分离株在草莓上引起不同程度的轮枝菌萎蔫。对大丽轮枝菌1号生理小种有抗性且对大丽轮枝菌2号生理小种部分抗性的生菜品系对艾氏轮枝菌和克莱巴轮枝菌的所有分离株也表现出抗性。因此，艾氏轮枝菌和克莱巴轮枝菌种群中的至少一些分离株有可能成为加利福尼亚沿海作物的重要病原菌。然而，对大丽轮枝菌产生的抗性也至少在生菜中对这两个物种的致病分离株提供抗性。
