First and fifth authors: Division of Plant and Soil Sciences, West Virginia University, Morgantown 26506; second author: Departments of Plant Biology, and Plant, Soils and Microbial Sciences, and The Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing 48824; third author: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824; and fourth author: Department of Biology, University of Wisconsin-La Crosse, La Crosse 54601.
Phytopathology. 2018 Jun;108(6):702-710. doi: 10.1094/PHYTO-10-17-0354-R. Epub 2018 Apr 27.
Hypovirus-infected Cryphonectria parasitica strains were introduced in a large stand of American chestnut (>4,000 individuals) in western Wisconsin (USA) to evaluate whether hypoviruses can serve as biological control agents. They were deployed by treating cankers from 1992 to 1997 and again from 2004 to 2014. After 17 years of hypovirus introductions within an area of the stand with the longest history of disease, isolation of hypovirus-infected strains increased from 55% in 1994 to 86% in 2014 from cankers that were treated. During the same period, isolation from cankers that arose on trees with treated cankers increased from 29 to 72% and from 15 to 84% for cankers on nearby trees that received no treatment. Tree survivorship over the 23-year study period for trees with treated cankers was 51% compared with 31% for trees that were not treated. Introduction of hypovirus has resulted in the regrowth of the crowns of many large-diameter trees. Putative recovery of American chestnut in this stand provides evidence that prolonged hypovirus treatment can act as a biological control when limited numbers of vegetative compatibility types of C. parasitica exist.
被病毒感染的 Cryphonectria parasitica 菌株被引入美国威斯康星州西部的一个大型美洲山核桃林（超过 4000 株）中，以评估病毒是否可以作为生物防治剂。从 1992 年到 1997 年以及 2004 年到 2014 年，通过治疗溃疡来部署这些菌株。在该林分中，具有最长病史的区域内引入病毒后的 17 年中，从溃疡中分离出的病毒感染株的比例从 1994 年的 55%增加到 2014 年的 86%，这些溃疡都经过了处理。在此期间，从经过处理的溃疡树上出现的溃疡中分离出的比例从 29%增加到 72%，而从附近未经处理的树上出现的溃疡中分离出的比例从 15%增加到 84%。在经过 23 年的研究期间，对经过处理的溃疡的树木的存活率为 51%，而未经过处理的树木的存活率为 31%。引入病毒已导致许多大树的树冠重新生长。在该林分中，美洲山核桃的潜在恢复提供了证据，表明当存在有限数量的 C. parasitica 营养体亲和性类型时，长时间的病毒处理可以作为生物防治。
