摘要
为探究桑树内生细菌多样性,获得拮抗性内生菌,开发利用桑树内生菌资源,通过非培养法构建16S rDNA文库,并结合组织分离培养法对桐乡青(桑树品种)内生细菌的种群特征进行了研究.非培养法研究结果显示所构建文库的111个阳性克隆属于22个分类单元,其分属于3门10属,其中,鞘氨醇单胞菌属(Sphingomonas)、Massilia和甲基杆菌属(Methylobacterium)为优势菌属;使用不同培养基通过培养法从桐乡青茎中获得25个内生细菌分离株,基于16S rDNA序列系统发育分析其属于15个分类单元,其分属于3门12属,其中肠杆菌属(Enterobacter)、芽孢杆菌属(Bacillus)和泛菌属(Pantoea)为优势菌属.培养法得到的内生细菌种群与非培养法差异较大,仅假单胞菌属(Pseudomonas)和鞘氨醇单胞菌属(Sphingomonas)为共同菌属,且培养法得到的内生细菌多样性和均匀度指数(H'2.54,D 0.91,J 0.79)均高于非培养法(H'2.21,D 0.84,J 0.48).采用抑菌圈法,以10株植物病原菌作为指示菌,结果显示多达18株桑树内生细菌对一种或多种病原菌有抑制作用.综上结果表明,桑树内生细菌具有丰富的多样性,并且包含大量具有抗菌活性的菌株,以桐乡青材料为例,抗菌活性菌株约占其内生细菌的72%.
In order to lay a good foundation for the exploration and utilization of mulberry endophyte resources,the biodiversity of endophytes in mulberry was investigated and antibiotic endophytes were obtained in this study.A 16 S rDNA clone library was constructed by the culture-independent approach,and the community characteristics of mulberry endophytes in Tongxiangqing（a variety of mulberry） were investigated in combination with the tissue isolation culture method.Using common plant pathogens as the target,antagonistic endophytes were screened out.The results obtained with the culture-independent method showed that the 111 positive clones in the library constructed belonged to 22 operational taxonomic units,involving 10 genera of 3 phyla.Among them,Sphingomonas,Massilia and Methylobacterium were the dominant populations.Twenty-five isolates were obtained from mulberry stems with the culture-dependent method on different media.They were classified into 15 operational taxonomic units,involving 12 genera of 3 phyla,with Enterobacter,Bacillus and Pantoea being the dominant genera.The populations of endophytic bacteria obtained through the culture-dependent method were quite different from those gained through the culture-independent method.Only Pseudomonas and Sphingomonas were common genera between them.Furthermore,both the biodiversity index and the evenness index of endophytic bacteria obtained through the culture-dependent method（H＇ 2.54,D 0.91,J 0.79） were higher than those by the culture-independent method（H＇ 2.21,D 0.84,J 0.48）.Based on the results of an antagonism assay of 10 pathogens,as much as 18 endophytic bacteria in mulberry showed inhibitory activity on one or more pathogens.It is concluded from what is stated above that endophytic bacteria in mulberry have great biodiversity and contain a large number of strains with antimicrobial activity（72% of the total）.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2017年第1期36-45,共10页
Journal of Southwest University(Natural Science Edition)
基金
国家自然科学基金项目(31601678)
重庆市基础科学与前沿技术研究院士专项(NO.cstc2015jcyjys80001)
教育部留学回国人员科研启动基金项目(NO.教外司留2015-311)
关键词
桑树内生菌
非培养法
培养法
多样性
拮抗菌
mulberry endophytes
culture-independent method
culture-dependent method
biodiversity
antagonistic endophytes
