An amplicon metagenomic approach based on the ITS1 region of fungal rDNA was employed to identify the composition of fungal communities associated with diseases of pear fruits during postharvest storage. The sampled fruits were harvested at an orchard using routine management practices involving treatments with various chemical fungicides and were transferred to a storage packinghouse. Effective tags of reading sequences clustered into 53 OTUs whereas Ascomycota was the dominant phylum (83.4%) followed by Basidiomycota (15.8%). Our results revealed that four genera, Penicillium , Rhodotorula , Alternaria and Cladosporium were the most abundant representing 59–95% of the relative abundance per sample. The interruption of chemical treatments during the last month before harvest altered the structure of the fungal community of fruits among untreated and treated samples, mainly in cases of relative abundance of Penicillium and Rhodotorula genera. We hypothesize that various antagonistic interactions might occur on fruit surfaces among the detected fungal genera whose relative abundances were affected by fungicide treatments. Interestingly, some common pre- and postharvest pear fungal pathogens were either less present (such as Moniliana ) , or undetected (such as Aspergillus, Venturia and Septoria ) in untreated and treated samples.

中文翻译：

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管理措施影响下梨果实采后病害真菌群落宏基因组学分析

采用基于真菌 rDNA 的 ITS1 区域的扩增子宏基因组方法来鉴定与梨果实在采后储存期间疾病相关的真菌群落的组成。采样的水果是在果园采摘的，采用常规管理方法，包括用各种化学杀菌剂处理，然后转移到储存包装厂。阅读序列的有效标签聚集成 53 个 OTU，而子囊菌门是优势门 (83.4%)，其次是担子菌门 (15.8%)。我们的结果显示，四个属，青霉属、红酵母属、链格孢属和枝孢属是最丰富的，占每个样品相对丰度的 59-95%。收获前最后一个月化学处理的中断改变了未处理和处理样品中水果真菌群落的结构，主要是在青霉属和红酵母属相对丰度的情况下。我们假设检测到的真菌属之间的水果表面可能发生各种拮抗相互作用，其相对丰度受杀菌剂处理的影响。有趣的是，一些常见的采前和采后梨真菌病原体在未经处理和经处理的样品中要么较少存在（如念珠菌属），要么未检测到（如曲霉属、文丘里氏菌和壳孢菌属）。我们假设检测到的真菌属之间的水果表面可能发生各种拮抗相互作用，其相对丰度受杀菌剂处理的影响。有趣的是，一些常见的采前和采后梨真菌病原体在未经处理和经处理的样品中要么较少存在（如念珠菌属），要么未检测到（如曲霉属、文丘里氏菌和壳孢菌属）。我们假设检测到的真菌属之间的水果表面可能发生各种拮抗相互作用，其相对丰度受杀菌剂处理的影响。有趣的是，一些常见的采前和采后梨真菌病原体在未经处理和经处理的样品中要么较少存在（如念珠菌属），要么未检测到（如曲霉属、文丘里氏菌和壳孢菌属）。