青檀内生和附生真菌群落多样性的季节性变化

Seasonal Variations in the Diversity of Endophytic and Epiphytic Fungal Communities in Pteroceltis tatarinowii

【目的】了解青檀(Pteroceltis tatarinowii)内生和附生真菌的群落结构及其季节性特征,并探讨群落间的关系及多样性形成的可能原因。【方法】在不同季节分别采集野生青檀当季生长的健康枝条,采用组织分离和振荡清洗涂布平板法分离内生和附生真菌,并对其进行培养、鉴定以及群落多样性分析。【结果】青檀的内生和附生真菌群落主要由子囊菌门(Ascomycota)构成,分别占94.78%和87.62%。内生真菌主要包括拟茎点霉属(Phomopsis)、交链孢属(Alternaria)和曲霉属(Aspergillus),三者合计占比为76.10%;拟茎点霉属和刺盘孢属(Colletotrichum)在每个季节均出现;拟茎点霉属为第1优势菌属,春、夏、秋、冬季占比分别为89.65%、43.51%、35.51%和75.35%。附生真菌则主要由青霉属(Penicillium)、茎点霉属(Phoma)和拟茎点霉属构成,三者合计占比为55.05%;每个季节均出现交链孢属、拟茎点霉属和刺盘孢属。春季时,内生真菌的多样性、丰富度和均匀度均低于附生真菌,而在夏、秋季则相反;冬季时,内生真菌的多样性和均匀度较低,但丰富度较高。2个群落组成的相似度较高(Cs=0.76),无显著性差异(P>0.05)。【结论】青檀的内生与附生真菌群落丰富且相似度高,存在明显的季节差异。季节更替导致青檀内外生态因子变化,从而驱动内生和附生真菌群落多样性的变化。

[Purpose]To investigate the community structure and seasonal characteristics of endophytic and epiphytic fungi in Pteroceltis tatarinowii,exploring the relationships between communities and the potential reasons for the observed diversity.[Methods]Healthy twigs of wild P.tatarinowii were collected in different seasons.Endophytic and epiphytic fungi were isolated using tissue separation and oscillation washing plate methods.The culture,identification and community diversity analysis of fungi were carried out.[Results]The fungal communities of P.tatarinowii were predominantly composed of Ascomycota,accounting for 94.78%and 87.62%of endophytic and epiphytic fungi,respectively.Endophytic fungi were primarily comprised of Phomopsis,Alternaria,and Aspergillus,representing 76.10%of the total.Phomopsis and Colletotrichum appeared in each season,with Phomopsis as the dominant genus,accounting for 89.65%,43.51%,35.51%,and 75.35%,respectively in spring,summer,autumn and winter.Epiphytic fungi were mainly composed of Penicillium,Phoma,and Phomopsis,comprising 55.05%of the total,with Alternaria,Phomopsis,and Colletotrichum appearing each season.In spring,the diversity,richness,and evenness of endophytic fungi were lower than those of epiphytic fungi,whereas in summer and autumn,the opposite was true;in winter,endophytic fungi had lower diversity and evenness but higher richness.The similarity index between the two communities was high(Cs=0.76),with no significant difference(P>0.05).[Conclusion]The endophytic and epiphytic fungal communities in P.tatarinowii are diverse and highly similar,exhibiting seasonal differences.Seasonal changes cause shifts in the internal and external ecological factors of P.tatarinowii,driving corresponding changes in community diversity.