Fungicide Effects on Fungal Community Composition in the Wheat Phyllosphere

The fungicides used to control diseases in cereal production can have adverse effects on non-target fungi, with possible consequences for plant health and productivity. This study examined fungicide effects on fungal communities on winter wheat leaves in two areas of Sweden. High-throughput 454 sequencing of the fungal ITS2 region yielded 235 operational taxonomic units (OTUs) at the species level from the 18 fields studied. It was found that commonly used fungicides had moderate but significant effect on fungal community composition in the wheat phyllosphere. The relative abundance of several saprotrophs was altered by fungicide use, while the effect on common wheat pathogens was mixed. The fungal community on wheat leaves consisted mainly of basidiomycete yeasts, saprotrophic ascomycetes and plant pathogens. A core set of six fungal OTUs representing saprotrophic species was identified. These were present across all fields, although overall the difference in OTU richness was large between the two areas studied.用于谷物生产中病害防控的杀菌剂，可对非靶标真菌产生不利影响，进而可能影响植物健康与生产效率。本研究以瑞典两个区域的冬小麦叶片真菌群落为研究对象，探究了杀菌剂的作用效应。通过对真菌ITS2区域开展高通量454测序，从18个受试农田中共获得235个物种级操作分类单元（operational taxonomic units，OTU）。研究结果表明，常用杀菌剂对小麦叶围真菌群落组成具有中等程度但显著的调控作用。杀菌剂施用会改变多种腐生真菌的相对丰度，但其对常见小麦病原菌的影响则参差不齐。小麦叶片的真菌群落主要由担子菌酵母、腐生子囊菌与植物病原菌构成。本研究鉴定出一组包含6个腐生真菌物种的核心OTU，尽管两个研究区域间的OTU丰富度整体差异较大，但该核心OTU集合在所有受试农田中均有分布。