Soil Cares Research, 6709 PA Wageningen, The Netherlands.
Microbiol Spectr. 2016 Dec;4(6). doi: 10.1128/microbiolspec.FUNK-0013-2016.
Fungal plant pathogens are ubiquitous and highly diverse. Key to their success is high host density, which notably is the case in agroecosystems. Several hypotheses related to the effects of plant pathogens on plant diversity (the Janzen-Connell hypothesis, the dilution effect hypothesis) and the phenomenon of higher biomass in plant mixtures (i.e., overyielding) can all be explained by the quantitative interplay between host and pathogen density. In many agroecosystems, fungal plant pathogens cause great losses, since in monocultures diseased plants cannot be replaced by healthy plants. On the other hand, in natural ecosystems fungal plant pathogens shape the succession of vegetation and enhance the biodiversity of forests and grasslands. When pathogens are introduced into areas outside their natural range, they may behave differently, causing severe damage. Once introduced, changes may occur such as hybridization with other closely related pathogens or host shifts, host jumps, or horizontal gene transfer. Such changes can be hazardous for both agricultural and natural ecosystems.
真菌植物病原体无处不在且具有高度多样性。它们成功的关键是高宿主密度，特别是在农业生态系统中。与植物病原体对植物多样性的影响（詹森-康奈尔假说、稀释效应假说）以及植物混合物中更高生物量的现象（即超产）相关的几个假说都可以通过宿主和病原体密度之间的定量相互作用来解释。在许多农业生态系统中，真菌植物病原体造成了巨大的损失，因为在单一种植中，患病植物无法被健康植物所替代。另一方面，在自然生态系统中，真菌植物病原体塑造了植被的演替，并增强了森林和草原的生物多样性。当病原体被引入其自然范围之外的地区时，它们的行为可能会有所不同，从而造成严重的破坏。一旦引入，就可能发生变化，例如与其他密切相关的病原体杂交或宿主转移、宿主跳跃或水平基因转移。这些变化对农业和自然生态系统都可能是危险的。
