青杨雌雄株叶际微生物群落多样性和结构的差异

Differences in phyllosphere microbial communities between female and male Populus cathayana

【目的】本论文探究了青杨雌雄株的叶际微生物的群落结构差异及其主要环境影响因素。【方法】以河北小五台山的天然青杨林为研究对象,采用基于16S rRNA/ITS1基因的MiSeq高通量测序技术,分析了青杨雌雄株叶际细菌和真菌的群落结构,并耦合分析其与叶片理化性质的相关性。【结果】测序结果表明细菌和真菌的多样性指数ACE、Chao1、Shannon、Simpson在雌雄株间都无显著性差异(P>0.05)。Metastats组间群落显著性差异分析表明,在门水平,青杨雌雄株叶际细菌和真菌都无显著差异。而在属水平,青杨雌雄株的叶际细菌Amnibacterium和Spingomonas及真菌Aureobasidium、Elmerina、Exobasidium、Endoconidioma、Monilinia和Rhodotorula的相对丰度在雌雄株叶际有显著差异(P<0.05)。基于OTUs的菌群分析表明,青杨雌株和雄株的叶际环境上都有其各自的特有菌群,如雌株的特有真菌Pringsheimia(0.15%)和细菌Chitinophaga(0.04%)。RDA冗余分析表明,叶片含水量与青杨叶际真菌的群落结构有显著相关性(P<0.05),而未发现青杨细菌群落结构与测定的叶片理化性质有显著相关。【结论】青杨雌雄株叶际微生物在属水平有显著分异的菌属,且可能受叶片理化性质影响,该结果为揭示雌雄异株植物的叶际微生物差异有重要借鉴意义。

[Objective]In this study,the difference of female and male Populus cathayana phyllosphere microbial community structure,and their key environmetal factors in driving the differences were investigated.[Methods]The natural Populus cathayana forest of Xiaowutai Mountain in Hebei province was chosen to explore the phyllosphere bacterial and fungal community composition of female and male Populus cathayana using 16S rRNA/ITS1 gene-based MiSeq sequencing,and their relationships with leaves physicochemical properties.[Results]The microbial diversity indexes showed no significant difference between female and male phyllosphere microbial communities(P>0.05).Significant differences in the relative abundance of bacterial genera Amnibacterium and Spingomonas(P<0.05),and fungal genera Aureobasidium,Elmerina,Exobasidium,Endoconidioma,Monilinia and Rhodotorula were detected between sexes by Metastats analysis.The microbiota analysis based on OTUs showed that both male and female of Populus cathayana had their unique phyllosphere bacteria and fungi microbiota,such as fungi Pringsheimia(0.15%)and bacteria Chitinophaga(0.04%)in the female phyllosphere.Redundancy analysis indicated the leaves moisture content significantly influenced phyllosphere fungal community structure of Populus cathayana(P<0.05),while no significant correlation was found between the phyllosphere bacterial community structure and the leaves physicochemical properties.[Conclusion]There were significant differences in relative abundance of phyllosphere bacterial and fungal at genus level between female and male Populus cathayana,and the structure of phyllosphere microbial community of different plants might be affected by the leaves physicochemical properties,which provided insight for exploring the differences of phyllosphere microorganism between dioecious plants.