Abstract The aerial portion of plants (phyllosphere) harbors complex and diverse microbial communities that have been shown to influence host growth and fitness, tolerance to environmental stressors, disease susceptibility, and the productivity of economically significant crops. However, despite its reproductive importance to the host and economic value, the microbial ecology of anatomical flowers (anthosphere) remains largely uninvestigated. Here a culture-independent assessment of bacterial communities on freshly harvested and dried inflorescences of eight hop varieties (Humulus lupulus L.), using Illumina MiSeq 16S platform-based rRNA gene sequence analysis, is reported. The results reveal the hops anthosphere is dominated by a single taxonomic phylum, the Proteobacteria, where at least 60% of the sequences are attributed across two genera, Pseudomonas (Gammaproteobacteria) and Sphingomonas (Alphaproteobacteria). Chao1 diversity analysis indicated the presence of many very rare taxa across all varieties. Beta-diversity analysis resolved, from the comparison of unweighted and weighted UniFrac distances, the absence of distinct clustering between freshly harvested and dried hops or between hop varieties. The prevalence of Proteobacteria associated with hop inflorescences is consistent with other anthosphere microbiomes; however, presently the predominance of Gammaproteobacteria in the phyllosphere appears to be a distinct characteristic of the hops microbiome.

中文翻译：

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Humulus lupulus L 花序中微生物群落的表征。

摘要 植物的地上部分（叶际）拥有复杂多样的微生物群落，这些微生物群落已被证明会影响宿主的生长和适应性、对环境压力的耐受性、疾病易感性以及具有重要经济意义的作物的生产力。然而，尽管其对宿主的繁殖和经济价值具有重要意义，但解剖花（花圈）的微生物生态学在很大程度上仍未得到研究。这里报告了使用基于 Illumina MiSeq 16S 平台的 rRNA 基因序列分析对 8 个啤酒花品种 (Humulus lupulus L.) 新鲜收获和干燥花序的细菌群落进行独立培养评估。结果表明，啤酒花 anthosphere 由单一分类门 Proteobacteria 主导，其中至少 60% 的序列属于两个属，假单胞菌（Gammaproteobacteria）和鞘氨醇单胞菌（Alphaproteobacteria）。Chao1 多样性分析表明，所有品种都存在许多非常罕见的分类群。通过比较未加权和加权 UniFrac 距离，Beta 多样性分析解决了新鲜收获和干燥啤酒花之间或啤酒花品种之间没有明显聚类的问题。与啤酒花花序相关的变形菌的流行与其他花序微生物群落一致；然而，目前在叶际中 Gammaproteobacteria 的优势似乎是啤酒花微生物组的一个明显特征。从未加权和加权 UniFrac 距离的比较来看，新鲜收获的和干燥的啤酒花之间或啤酒花品种之间没有明显的聚类。与啤酒花花序相关的变形菌的流行与其他花序微生物群落一致；然而，目前在叶际中 Gammaproteobacteria 的优势似乎是啤酒花微生物组的一个明显特征。从未加权和加权 UniFrac 距离的比较来看，新鲜收获的和干燥的啤酒花之间或啤酒花品种之间没有明显的聚类。与啤酒花花序相关的变形菌的流行与其他花序微生物群落一致；然而，目前在叶际中 Gammaproteobacteria 的优势似乎是啤酒花微生物组的一个明显特征。