Schall Mark J, Davis Donald D
Department of Plant Pathology, The Pennsylvania State University, University Park 16802.
Plant Dis. 2009 Jul;93(7):747-751. doi: 10.1094/PDIS-93-7-0747.
Extensive, unprecedented wilt and mortality of the highly invasive tree-of-heaven (Ailanthus altissima) occurred recently within mixed-hardwood forests in south-central Pennsylvania. Until this study, the cause of the epidemic was unknown. Verticillium albo-atrum was consistently isolated from symptomatic Ailanthus seedlings and trees in areas having high levels of mortality, whereas V. dahliae was isolated from small scattered patches of diseased Ailanthus. Inoculations of potted Ailanthus seedlings in the greenhouse, as well as canopy trees in the field, revealed that both V. albo-atrum and V. dahliae were capable of infecting Ailanthus, but V. albo-atrum was more pathogenic. All Ailanthus seedlings and canopy trees inoculated with V. albo-atrum died within 3 months. In contrast, Ailanthus seedlings and canopy trees inoculated with V. dahliae became symptomatic, but 84% were still living 1 year following inoculation. We conclude that the major cause of Ailanthus wilt within forests of south-central Pennsylvania is V. albo-atrum. Pending further studies, including risk analysis, V. albo-atrum may be considered as a possible biocontrol agent for invasive Ailanthus.
近期，在宾夕法尼亚州中南部的混交硬木林中，极具入侵性的臭椿（Ailanthus altissima）出现了大面积、前所未有的枯萎和死亡现象。在本研究之前，这种流行病的病因尚不清楚。在死亡率高的地区，从有症状的臭椿幼苗和树木中持续分离出黑白轮枝菌（Verticillium albo-atrum），而大丽轮枝菌（V. dahliae）则从零星分布的小片患病臭椿中分离得到。在温室中对盆栽臭椿幼苗以及田间的冠层树木进行接种试验，结果表明黑白轮枝菌和大丽轮枝菌都能够感染臭椿，但黑白轮枝菌的致病性更强。所有接种了黑白轮枝菌的臭椿幼苗和冠层树木在3个月内死亡。相比之下，接种了大丽轮枝菌的臭椿幼苗和冠层树木出现了症状，但接种1年后仍有84%存活。我们得出结论，宾夕法尼亚州中南部森林中臭椿枯萎的主要原因是黑白轮枝菌。在包括风险分析在内的进一步研究完成之前，黑白轮枝菌可被视为入侵性臭椿的一种可能的生物防治剂。
