| 摘要: |
| 【目的】研究白粉病对大叶黄杨（Euonymus japonicus）叶片内生细菌群落结构特征、互作关系及群落关键种的影响，为大叶黄杨白粉病的生物防治提供参考。【方法】以北京市大叶黄杨绿化带的健康叶片（HL）及感染白粉病叶片（DL）为材料，测定其硝酸盐、可溶性糖、可溶性蛋白及叶绿素含量。采用Illumina MiSeq测序技术测定叶片内生细菌群落特征，用ADONIS、MRPP和PERMANOVA方法分析细菌群落不相似性，采用典范对应分析（CCA）和Mantel分析研究细菌群落结构与叶片理化指标的相关性，通过细菌群落的分子生态网络分析（MENA）确定群落互作关系及关键种。【结果】大叶黄杨DL的叶绿素含量显著低于HL，而可溶性蛋白质含量显著高于HL。大叶黄杨HL和DL叶内生细菌群落的多样性及群落结构无显著差异。HL优势菌门为变形菌门、放线菌门、厚壁菌门、蓝细菌门、拟杆菌门，DL优势菌门为变形菌门、放线菌门、厚壁菌门、蓝细菌门。HL优势属相对丰度从高到低依次为罗尔斯通氏菌属、无色杆菌属、贪铜菌属、类芽孢杆菌属、盐孢菌属、芽孢杆菌属、伯克霍尔德菌属、土单胞菌属、节杆菌属；DL优势属为罗尔斯通氏菌属、盐孢菌属、伯克霍尔德菌属、芽孢杆菌属、罗河杆菌属。大叶黄杨叶片的叶绿素含量显著影响细菌群落结构，主要影响HL的变形菌门和放线菌门相对丰度。MENA结果显示，DL内生细菌群落的互作关系比HL更复杂，竞争关系更强。HL内生细菌群落中未发现关键种，而DL中发现了5个细菌群落关键种，分别为放线菌门的诺卡氏菌科红球菌属、类诺卡氏菌科和鱼孢菌科及变形菌门的生丝微菌科丝微菌属和华杆菌科。【结论】白粉病感染对大叶黄杨叶片内生细菌群落结构及多样性无显著影响，但改变了细菌群落的互作关系，说明大叶黄杨叶片内生细菌对白粉病的感染具有响应效应。 |
| 关键词: 大叶黄杨 白粉病 叶片内生细菌群落 分子生态网络 |
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| 基金项目:北京林业大学建设世界一流学科和特色发展引导专项“园林植物高效繁殖与栽培技术研究”（2019XKJS0324） |
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| Responses of endophytic bacterial community in leaves of Euonymus japonicus to powdery mildew |
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WU Luyao,ZHANG Zhuo,KONG Xiao,et al
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| Abstract: |
| 【Objective】The effects of powdery mildew on endophytic bacterial community structure,interaction and key species in leaves of Euonymus japonicus were studied to provide reference for biological control of powdery mildew.【Method】The contents of nitrate,soluble sugar,soluble protein and chlorophyll of healthy leaves (HL) and diseased leaves (DL) of Euonymus japonicus belt in Beijing were measured.The endophytic bacterial community in leaves was identified by Illumina MiSeq sequencing technology,and ADONIS,MRPP and PERMANOVA were used to analyze the dissimilarity of bacterial community.The correlation between bacterial community structure and leaf physicochemical properties was analyzed by Mantel analysis and canonical correspondence analysis (CCA).Molecular ecological network approach (MENA) was used to identify community interactions and key species.【Result】The chlorophyll content of DL was significantly lower than that of HL,while the soluble protein content of DL was significantly higher than that of HL.There was no difference in the diversity and community structure of endophytic bacterial communities between the two groups.The dominant phylas of HL were Proteobacteria,Actinobacteria,Firmicutes,Cyanobacteria and Bacteroidetes,and the dominant phylas of DL were Proteobacteria,Actinobacteria,Firmicutes and Cyanobacteria.The relative abundance of HL dominant generas was in the decreasing order of Ralstonia,Achromobacter,Cupriavidus,Paenibacillus,Salinispora,Bacillus,Burkholderia,Terrimonas and Arthrobacter.The dominant genera of DL were Ralstonia,Salinispora,Burkholderia,Bacillus and Rhodanobacter.The chlorophyll content in leaves of Euonymus japonicus significantly affected the bacterial community structure,mainly by affecting the relative abundance of Proteobacteria and Actinobacteria of HL.According to MENA,DL had more complex endophytic bacteria community interaction and stronger competition than HL.In addition,there were 5 key species in DL,including Rhodococcus Nocardiaceae,Nocardioidaceae,Sporichthyaceae,belong to Actinobacteria and Hyphomicrobium Hyphomicrobiaceae,Sinobacteraceae,belong to Proteobacteria，while no key species were found in HL endophytic bacterial community.【Conclusion】The infection of powdery mildew had no significant effect on the structure and diversity of endophytic bacteria in leaves of Euonymus japonicus,but it changed the interaction of bacterial community.The changes of key species indicated that the endophytic bacteria in leaves of Euonymus japonicus responded to the infection of powdery mildew. |
| Key words: Euonymus japonicus powdery mildew leaf endophytic bacteria community molecular ecological network |
