基于盆栽试验的苯并噻唑硫酮对感染青枯病烟株根围土壤细菌群落结构的影响

Effects of 3-methylbenzothiazole-2-thione on community structure of bacteria in rhizospheric soil of tobacco plants infected by bacterial wilt

为明确玉米根系分泌物3-甲基-2(3H)苯并噻唑硫酮(简称苯并噻唑硫酮)灌根处理对感染青枯病烟株根围土壤细菌群落的影响机制,通过盆栽试验,采用Illumina MiSeq高通量测序技术对苯并噻唑硫酮灌根处理当天(0 d),处理后2、7、20和40 d共5个时期烟株根围土壤中细菌群落结构进行分析。结果表明:①苯并噻唑硫酮灌根40 d后烟株无明显青枯病症状,而对照灭菌蒸馏水灌根40 d后烟株均枯萎死亡。②苯并噻唑硫酮灌根处理后,烟株根围细菌Alpha多样性指数中Sobs指数、Chao1指数以及香农指数(Shannon)升高。③苯并噻唑硫酮处理后5个时期的共有优势菌门为放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和绿弯菌门(Chloroflexi);共有优势菌属为Pseudarthrobacter、鞘氨醇单胞菌属(Sphingomonas)和芽单胞菌属(Gemmatimonas)。④苯并噻唑硫酮灌根处理可提高烟株根围土壤中放线菌门相对丰度,降低Saccharibacteria菌门相对丰度,增加类诺卡氏属(Nocardioides)、Streptomyces和链霉菌属(Streptomyces)相对丰度,降低鞘氨醇单胞菌属(Sphingomonas)相对丰度。因此,苯并噻唑硫酮灌根能有效防治烟草青枯病,并影响烤烟根围细菌群落结构,增加有益菌相对丰度。

In order to clarify the affecting mechanism of root irrigation with 3-methylbenzothiazole-2-thione secreted by corn roots on the community structure of bacteria in the rhizospheric soil of tobacco plants infected by bacterial wilt,Illumina MiSeq high-throughput sequencing technology was used to analyze the community structure of bacteria in the rhizospheric soil of tobacco plants infected by bacterial wilt on the day of the root irrigation as well as the 2nd,7th,20th and 40th days after root irrigation through pot experiments.The results showed that:1)There was no obvious bacterial wilt symptom 40 days after root irrigation with 3-methylbenzothiazole-2-thione,while all tobacco plants withered and died 40 days after root irrigation with sterilized distilled water.2)After root irrigation with 3-methylbenzothiazole-2-thione,Sobs index,Chao1 index and Shannon index of Alpha diversity indexes of bacteria in rhizospheric soil of tobacco plants increased.3)The dominant phyla were Actinobacteria,Proteobacteria and Chloroflexi and the dominant genera were Pseudarthrobacter,Sphingomonas and Gemmatimonas in all the five stages after irrigation with 3-methylbenzothiazole-2-thione.4)Root irrigation with 3-methylbenzothiazole-2-thione increased the relative abundances of Actinobacteria,Nocardioides and Streptomyces and decreased the relative abundances of Saccharacteria and Sphingomonas in the rhizospheric soil of tobacco plants.Therefore root irrigation with 3-methylbenzothiazole-2-thione can effectively control tobacco bacterial wilt,affect the community structure of bacteria in the rhizospheric soil of flue-cured tobacco,and increase the relative abundances of beneficial bacteria.