重庆地区玉米叶内生细菌的分离及其与草地贪夜蛾肠道菌的比较

为进一步了解重庆地区玉米叶内生细菌的组成以及这些内生细菌与入侵重庆地区草地贪夜蛾肠道微生态的相互关系,以采集自巫山地区被草地贪夜蛾入侵的玉米地里的玉米嫩叶为材料,运用传统微生物培养方法尝试对其内生细菌进行初步的分离培养,并通过16S rDNA测序开展了优势菌的属水平鉴定.此次共分离获得了22个细菌分离株,经16S rDNA序列同源性分析,将它们归类到11个分类单元,分属克雷伯氏菌属(Klebsiella)、不动杆菌属(Acinetobacter)、寡养单胞菌属(Stenotrophomonas)、芽孢杆菌属(Bacillus)、肠球菌属(Enterococcus)、微杆菌属(Microbacterium)、鞘氨醇杆菌属(Sphingobacterium)、金黄杆菌属(Chryseobacterium)、无色杆菌属(Achromobacter)和丛毛单胞菌属(Comamonas).与前期研究得到的该地区草地贪夜蛾肠道微生物菌群数据比较可以发现,玉米内生细菌中包括克雷伯氏菌属(Klebsiella)、不动杆菌属(Acinetobacter)、肠球菌属(Enterococcus)、鞘氨醇杆菌属(Sphingobacterium)和金黄杆菌属(Chryseobacterium)在内的5个属可以在草地贪夜蛾肠道中分离到,表明草地贪夜蛾肠道微生物多数可能源自其食物,但是草地贪夜蛾肠道微生物中常见的假单胞菌属(Pseudomonas)、肠杆菌属(Enterobacter)、类芽孢杆菌属(Paenibacillus)、短波单胞菌属(Brevundimonas)和气单胞菌属(Aeromonas)并未在玉米嫩叶中分离到,说明它们可能是主要存在于草地贪夜蛾肠道中的微生物.该研究对草地贪夜蛾所取食的玉米叶中内生细菌的种类进行了初步分析,为后续研究玉米叶内生细菌和草地贪夜蛾肠道微生物的相互关系奠定了基础.

Isolation and Identification of Endophytic Bacteria of Maize Leaf in Chongqing Area and Comparison Between Maize Microbes and Gut Bacteria of Spodoptera frugiperda

In order to understand the composition of endophytic bacteria in the maize leaf which were found in fall armyworm (FAW,Spodoptera frugiperda),the dominant bacteria from the samples collected from maize fields in Wushan of Chongqing were isolated with the traditional culture method and identified with 16SrDNA sequencing. A total of 22 isolates of endophytic bacteria were obtained,and were clustered in 16SrDNA homology analyses into 11 taxa,i.e. Klebsiella,Acinetobacter,Stenotrophomonas,Bacillus,Enterococcus,Microbacterium,Sphingobacterium,Chryseobacterium,Achromobacter and Comamonas. In comparison with our previous study about gut bacteria of FAW,5 genera including Klebsiella,Acinetobacter,Enterococcus,Sphingobacterium and Chryseobacterium were also isolated from the gut or feces of FAW,suggesting that a large amount of the gut bacteria may come from bacterial endophytes of maize. However,we failed to isolate genera like Pseudomonas,Enterobacter, Paenibacillus, Brevundimonas and Aeromonas,indicating that these bacteria may mainly exist in the gut of FAW. In conclusion,our study has identified the generic composition of the endophytic bacteria in maize leaf and determined their abundance,which may serve as a basis for future work on understanding the interaction between FAW core intestinal microorganisms and maize endophytes.