腾冲红花油茶花梗内生细菌的多样性

Diversity of endophytic bacteria in pedicel of Camellia reticulate Lindl

【目的】探究腾冲红花油茶花梗内生细菌群落结构及其多样性,为腾冲红花油茶花梗中有益微生物的筛选和利用提供科学依据。【方法】采集12和60年生树龄的腾冲红花油茶花梗,基于高通量测序技术探究其内生细菌多样性及群落结构差异。【结果】分类操作单元(OTU)和α多样性分析表明,2种树龄腾冲红花油茶花梗内生细菌丰富度和物种种类存在差异。在2种树龄腾冲红花油茶花梗中均检测出4个细菌门,其中变形菌门(Proteobacteria)相对丰度最高,在2组样品中占比均达60%以上。60年生样品检测到的特有细菌属包括游动放线菌属(Actinoplanes)、小单孢菌科未分类属(unclassified_f_Micromonosporaceae)和甲基球菌科未分类属(unclassified_f_Methylopilaceae),优势细菌属为鞘氨醇单胞菌属(Sphingomonas)、甲基杆菌—原单胞菌属(Methylobacterium-Methylorubrum)、1174-901-12、羊膜杆菌属(Amnibacterium)和Kineosporia;12年生样品的优势细菌属为1174-901-12、鞘氨醇单胞菌属、甲烷氧化细菌属(Methylocella)、酸杆菌属(Terriglobus)和甲基杆菌—原单胞菌属。2组样品中部分内生细菌在门和属水平的相对丰度呈显著差异(P<0.05,下同)。腾冲红花油茶花梗内生细菌的基因功能主要涉及碳水化合物代谢、氨基酸代谢、能量代谢等。【结论】腾冲红花油茶花梗含有丰富的内生细菌,树龄大的腾冲红花油茶花梗中内生细菌多样性和丰富度显著增多,且优势细菌种类和相对丰度也发生改变。挖掘和利用腾冲红花油茶功能菌株时需充分考虑树龄因素。

【Objective】This paper explored the endophytic bacterial community structure and diversity of the pedicel of Camellia reticulate Lindl,so as to provide scientific basis for the selection and utilization of beneficial bacteria in the pedicel of C.reticulate.【Method】The pedicels of C.reticulate at 12 and 60 years old were collected to investigate the diversity and community structure of endophytic bacteria based on high-throughput sequencing technology.【Result】Operational taxonomic unit OTU andα-diversity analysis revealed that there were differences in abundance and species composition of endophytic bacteria in pedicels of C.reticulate of two tree ages.Four bacterial phyla were detected in both tree ages of pedicels of C.reticulate.Among them,the Proteobacteria was the most abundant,accounting for more than 60%in both groups.The specific bacterial genera of 60 years old group were Actinoplanes,unclassified_f_Micromonosporaceae,unclassified_f_Methylococcaceae,and the dominant bacterial genera were Sphingomonas,Methylobacterium-Methylorubrum,1174-901-12,Amnibacterium and Kineosporia.The dominant bacterial genera of 12 years old C.reticulate were 1174-901-12,Sphingomonas and Methylobacterium-Methylorubrum.The relative abundance of some endophytic bacteria in the two groups showed significant differences at the phylum and genus levels(P<0.05,the same below).The gene functions of endophytic bacteria in pedicels of C.reticulate mainly involved carbohydrate metabolism,amino acid metabolism,energy metabolism,etc.【Conclusion】The pedicels of C.reticulate contain abundant endophytic bacteria.The diversity and abundance of endophytic bacteria significantly increase and the species and abundance of dominant bacteria also change in the pedicels of older C.reticulate.Tree age should be considered when excavating and utilizing functional strains of C.reticulate.