不同树龄杜仲内生真菌群落结构解析及优势菌群动态变化

Endophytic fungal community structure and dynamic changes of dominant flora in different ages of Eucommia ulmoides

目的探究不同树龄杜仲内生真菌群落组成、丰度及多样性,比较不同树龄杜仲内生真菌优势菌群随季节的动态变化规律。方法采集不同树龄的杜仲叶片与枝条,利用高通量测序解析内生真菌群落结构,并进行生物信息学分析。结果不同树龄杜仲之间存在较多共有可操作分类单元(operational taxonomic units,OUTs),杜仲树龄越低所具有的特有OTUs数量越多;不同树龄杜仲内生真菌群落的alpha多样性指数之间无显著差异,树龄越高alpha多样性指数越高;67年生与45年生杜仲内生真菌群落组成差异较小,28年生杜仲内生真菌群落组成与其他两组差异较大;杜仲中的优势菌门为子囊菌门(Ascomycota),其次为担子菌门(Basidiomycota);不同树龄杜仲所共有的优势菌属有9个,包括德福里斯孢属(Devriesia)、间座壳属(Diaporthe)、多臂菌属(Trichomerium)、亚球壳属(Sphaerulina)、短柄霉属(Aureobasidium)、近球腔菌属(Paramycosphaerella)、黑孢霉属(Nigrospora)、帚枝霉属(Sarocladium)和毕赤酵母属(Pichia),构成杜仲核心内生真菌组,其中Trichomerium、Sphaerulina仅在春季具有较高相对丰度,Paramycosphaerella仅在夏季具有较高相对丰度,Nigrospora、Sarocladium、Pichia仅在秋季具有较高相对丰度;基于FUNGuild预测,杜仲内生真菌中的优势菌群主要为植物病原菌。结论杜仲中具有核心内生真菌组,不同树龄杜仲内生真菌优势菌属的相对丰度不同,优势菌属的种类随季节变化而演替,树龄是使同一生境下杜仲内生真菌群落结构和多样性产生差异的主要因素。

Objective To observe the composition,abundance and diversity of endophytic fungal communities in different ages of Eucommia ulmoides,and compare the dynamic changes with seasons of the dominant populations of endophytic fungi in different ages of Eucommia ulmoides.Methods Leaves and branches of different ages of Eucommia ulmoides were collected and the endophytic fungal community structure was analyzed using Illumina HiSeq High-throughput sequencing,and bioinformatics analysis was performed.Results There were many shared operational taxonomic units(OTUs)among different ages of Eucommia ulmoides.The lower the age of Eucommia ulmoides,the higher the number of unique OTUs.The differences in the alpha diversity indices of endophytic fungal communities among different ages of Eucommia ulmoides were not significant.The higher the age of Eucommia ulmoides,the higher the alpha diversity index.The difference in the endophytic fungal community composition between 67-year-old and 45-year-old Eucommia ulmoides was small,while that between 28-year-old Eucommia ulmoides and the other two groups was large.The dominant phylum in Eucommia ulmoides was Ascomycota,followed by Basidiomycota.There were nine dominant genera shared by differ ent ages of Eucommia ulmoides,including Devriesia,Diaporthe,Trichomerium,Sphaerulina,Aureobasidium,Paramycosphaerella,Nigrospora,Sarocladium and Pichia,which constitute the core endophytic fungal group of Eucommia ulmoides.Trichomerium and Sphaerulina only had high relative abundance in spring,Paramycosphaerella only had high relative abundance in summer,while Nigrospora,Sarocladium and Pichia only had high relative abundance in autumn.Based on the FUNGuild forecast,the dominant groups of endophytic fungi in Eucommia ulmoides were mainly phytopathogens and undefined saprophytes.Conclusion There are core endophytic fungal group in Eucommia ulmoides.The relative abundance of endophytic fungal dominant genera varied among different ages of Eucommia ulmoides,and the species of dominant genera succeed with seasonal changes.The age of trees is an important factor that causes differences in the structure and diversity of endophytic fungal communities of Eucommia ulmoides in the same habitat.