Knaus B J, Fieland V J, Graham K A, Grünwald N J
Horticultural Crops Research Unit, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Corvallis, OR.
Department of Botany and Plant Pathology, Oregon State University, Corvallis.
Plant Dis. 2015 Oct;99(10):1326-1332. doi: 10.1094/PDIS-09-14-0964-RE. Epub 2015 Aug 11.
The genus Phytophthora contains some of the most notorious plant pathogens affecting nursery crops. Given the recent emergence of the sudden oak death pathogen Phytophthora ramorum, particularly in association with Rhododendron spp., characterization of Phytophthora communities associated with this host in nursery environments is prudent. Many taxa may present symptoms similar to P. ramorum but we do not necessarily know their identity, frequency, and importance. Here, we present a survey of Phytophthora taxa observed from seven nurseries in the U.S. state of Oregon. Incidence and diversity of Phytophthora communities differed significantly among nurseries and among seasons within nursery. The taxa P. syringae and P. plurivora were widespread and detected at most of the nurseries sampled. Nine other taxa were also detected but were found either in a single nursery or were shared among only a few nurseries. Characterization of the Phytophthora communities present in nurseries is an important step toward understanding the ecology of these organisms as well as an aid to nursery managers in determining what risks may be present when symptomatic plants are observed. This study builds on an increasing literature, which characterizes Phytophthora community structure in nurseries.
疫霉属包含一些对苗木作物危害最大的臭名昭著的植物病原体。鉴于最近突然出现的橡树猝死病原体——栎树猝死病菌（Phytophthora ramorum），尤其是其与杜鹃花属植物相关联，因此，对苗圃环境中与该寄主相关的疫霉群落进行特征描述是很有必要的。许多分类单元可能会呈现出与栎树猝死病菌相似的症状，但我们不一定知道它们的身份、出现频率及重要性。在此，我们展示了一项对美国俄勒冈州七个苗圃中观察到的疫霉分类单元的调查。疫霉群落的发生率和多样性在不同苗圃之间以及同一苗圃的不同季节之间存在显著差异。丁香疫霉（P. syringae）和多主疫霉（P. plurivora）这两个分类单元分布广泛，在大多数采样苗圃中都能检测到。还检测到了其他九个分类单元，但它们要么只在一个苗圃中被发现，要么仅在少数几个苗圃中共有。描述苗圃中存在的疫霉群落是了解这些生物生态学的重要一步，同时也有助于苗圃管理者确定在观察到有症状的植物时可能存在哪些风险。这项研究建立在越来越多的文献基础之上，这些文献对苗圃中的疫霉群落结构进行了特征描述。
