陆均松和青梅叶际真菌群落多样性特征及其影响因子

Diversity characteristics of phyllosphere fungal communities and their influencing factors in Dacrydium pectinatum and Vatica mangachapoi

【目的】陆均松和青梅是海南岛热带雨林中珍稀濒危树种。研究陆均松和青梅叶际真菌群落多样性和结构组成及其环境驱动因子,为未来利用微生物群落提供的有益功能来提高珍稀濒危植物生长适应性提供理论依据。【方法】通过对陆均松和青梅叶际真菌样品进行高通量测序,分析叶际真菌群落α、β多样性和群落组成,并阐明其主要环境驱动因子。【结果】1)本研究共分析检测到10 489个OTU,其中包括真菌10门40纲。陆均松和青梅的叶表共有OTU为523(4.99%),叶内共有OTU仅为9(0.09%)。2)优势菌纲包括:座囊菌纲(Dothideomycetes)、散囊菌纲(Eurotionmycetes)、银耳纲(Tremellomycetes)。其中青梅叶内的座囊菌纲相对丰度显著大于其他物种和隔室(P<0.01)。3)叶表真菌α多样性均高于叶内,但在不同物种上叶际真菌多样性差异不显著,物种变化解释了叶际真菌群落组成差异的13.57%(P<0.001);4)叶际真菌α多样性与叶片pH值、温度呈显著正相关(pH:R^(2)=0.16,P<0.001;Tem:R^(2)=0.16,P<0.001),同时与降水量呈显著负相关(Rain:R^(2)=0.35,P<0.001)。CCA分析结果显示,Mg、降水量对叶表真菌群落组成的解释度分别为:71.29%、69.33%;pH值、Mg对叶内真菌群落组成的解释度分别为:62.48%、61.51%。5)置换多元方差分析(PERMANOVA)结果说明全氮(TN:R^(2)=0.13,P=0.001)、全磷(TP:R^(2)=0.12,P=0.001)、Mg(Mg:R^(2)=0.14,P=0.001)、降水量(Rain:R^(2)=0.13,P=0.002)是陆均松和青梅叶际真菌组成差异的主要驱动因子。【结论】物种变化显著影响了叶际真菌群落,全氮(TN)、全磷(TP)、Mg是驱动陆均松和青梅叶际真菌群落组成差异的主要影响因子。

【Objective】Dacrydium pectinatum and Vatica mangachapoi are rare and endangered species in the tropical rainforests of Hainan Island.Investigating the diversity and structural composition of phyllosphere fungal communities and their environmental drivers in D.pectinatum and V.mangachapoi,which can provide a theoretical basis for the future utilization of the beneficial functions provided by microbial communities to improve the growth adaptability of rare and endangered plants.【Method】The high-throughput sequencing method was used to analyze phyllosphere fungal samples from D.pectinatum and V.mangachapoi,which explored the α and β diversity and community composition of the phyllosphere fungal communities and to elucidate their main environmental drivers.【Result】1) Atotal of 10 489 OTUs were analyzed and detected in this study,including 10 phyla and 40 orders of fungi.The leaf surface shared OTU was 523 (4.99%) and the leaf inner shared OTU was only 9 (0.09%) in D.pectinatum and V.mangachapoi.2) The dominant class included:Dothideomycetes,Eurotionmycetes,and Tremellomycetes.Among them,the relative abundance of Dothideomycetes on the leaf inner of V.mangachapoi was significantly greater than that of other species and compartments (P<0.01).3) All leaf surface fungal α-diversity was higher than leaf inner,but the difference between phyllosphere fungal diversity was not significant across species,with species variation explaining 13.57% of the variation in the composition of the phyllosphere fungal community (P<0.001).4) Phyllosphere fungal α-diversity showed a significant positive correlation with leaf pH and Temperature (pH:R^(2)=0.156,P<0.001;Tem:R^(2)=0.164,P<0.001),and also significantly negatively correlated with rainfall (Rain:R^(2)=0.345,P<0.001).The results of CCA analysis showed that Mg and rainfall explained 71.29% and 69.33% of the fungal community composition on the leaf surface,and pH and Mg explained 62.48% and 61.51% of the fungal community composition within the leaf inner,respectively.The PERMANOVA analysis indicated that total nitrogen (TN:R^(2)=0.13,P=0.001),total phosphorus (TP:R^(2)=0.12,P=0.001),Mg (R^(2)=0.14,P=0.001),and Rainfall (Rain:R^(2)=0.13,P=0.002) were the main drivers of the differences in the composition of the phyllosphere fungi of D.pectinatum and V.mangachapoi.【Conclusion】Species variation significantly affected the interleaf fungal community,with TN,TP and Mg being the main influences driving the differences in the composition of the phyllosphere fungal community between D.pectinatum and V.mangachapoi.