黄瓜疫霉菌拮抗内生细菌的筛选与鉴定  

Screening and Identification of Antagonistic Endophytic Bacteria Against Phytophthora drechsleri in cucumber

作　　者：郑京 梁乐霞 宣倩倩 郭慧滢 周志国[1] 孙泽敏 左国才 ZHENG Jing;LIANG Lexia;XUAN Qianqian;GUO Huiying;ZHOU Zhiguo;SUN Zemin;ZUO Guocai(College of Life Sciences,Langfang Normal University,Langfang 065000,China;School of Life Sciences,Beijing University of Technology,Beijing 100081,China)

机构地区：[1]廊坊师范学院生命科学学院,河北廊坊065000 [2]北京理工大学生命学院,北京100081

出　　处：《广东农业科学》2022年第4期81-87,共7页Guangdong Agricultural Sciences

基　　金：河北省自然科学基金(C2020408006);湖南省自然科学基金(2020JJ7007);廊坊市科技计划项目(2020013021)。

摘　　要：【目的】从黄瓜叶片中筛选抗疫霉菌效果好的内生细菌并进行鉴定,为进一步研究黄瓜疫病的理论探索及防治应用提供实验材料。【方法】以黄瓜叶片为实验材料筛选内生细菌,根据待检菌株的镜检特征、革兰氏染色反应、菌落排列方式和菌落形态特征等进行初步筛选。采用平板对峙法和发酵液拮抗法实验对目标内生细菌进行拮抗作用测定。通过16S rDNA序列测定及同源性分析,并构建系统发育树确定目标菌株种属。【结果】初步筛选出32株内生细菌将其编号为CL1~CL32,其中革兰氏阴性杆菌10株、革兰氏阳性杆菌13株、革兰氏阳性球菌9株,利用平板对峙法发现8株对掘氏疫霉菌有较强抑制作用的拮抗菌株,菌丝抑制率为10.3%~54.3%,抑菌半径为1~7 mm,对其中抑菌效果较好的3株菌株(CL7、CL9、CL15)进行发酵液拮抗实验,结果显示其抑菌率分别为54.4%、72.2%、63.3%。【结论】对掘氏疫霉菌具有较强抑制作用的3株内生细菌(CL7,CL9、CL15)分别属于泛菌属Pantoea sp.、假单胞菌属Pseudomonas sp.和葡萄球菌属Staphylococcus sp.,其中抑制效果最明显的为CL9,即假单胞菌属Pseudomonas sp.。【Objective】Endophytic bacteria with good resistance to Phytophthora were screened from cucumber leaves and identified,so as to provide experimental materials for further study of theoretical exploration and their application in controlling cucumber blight.【Method】Endophytic bacteria were screened from cucumber leaves,and were preliminarily screened according to microscopic characteristics,Gram staining reaction,colony arrangement and colony morphology.The antagonism of endophytic bacteria was tested by plate antagonism method and fermentation liquor antagonism method.Through 16S rDNA sequencing and homology analysis,phylogenetic tree was constructed to identify the target strains.【Result】Thirty-two endophytic bacteria were preliminarily screened and numbered as CL1-CL32,including 10 strains of Gram-negative bacillus,13 strains of Gram-positive bacillus and 9 strains of Gram-positive cocci.Eight strains were found to have strong inhibitory effect on Phytophthora drechsleri by plate confrontation method,and the inhibition rate of mycelia ranged from 10.3%to 54.3%.The inhibition radius ranged from 1 mm to 7 mm.Three strains(CL7,CL9,CL15)with better inhibitory effect were tested in fermentation liquor antagonism experiment,and the inhibition rates were 54.4%,72.2%,63.3%,respectively.【Conclusion】The three endophytic bacteria(CL7,CL9,CL15)with strong inhibitory effect on P.drechsleri belonged to Pantoea sp.,Pseudomonas sp.,and Staphylococcus sp.,among which CL9 belonging to Pseudomonas sp.had the most obvious inhibitory effect.

关 键 词：内生菌 鉴定 拮抗作用 菌丝抑菌率 掘氏疫霉 

分 类 号：S182[农业科学—农业基础科学]