大蒜内生细菌的分离及拮抗菌筛选与鉴定

利用常规分离方法对大蒜鳞茎进行内生细菌的分离,采用对峙法和平板涂布法对分离的内生菌进行拮抗试验研究,并对菌株DSP6进行16S rDNA全序列鉴定。结果表明:分离得到19株内生细菌,其中10株菌对2种以上植物病原真菌有不同程度的抑制作用,占分离菌总数的52.6%,DSN7对番茄早疫病的抑菌圈半径最大,为13mm;17株菌对5种病原细菌中至少1种有抑制作用,占分离菌总数的89.5%,其中菌株DSP3对大肠杆菌的抑菌圈半径最大,达到10 mm;菌株DSP6对供试的9种病原菌有较强的抑菌作用,且抑菌圈平均半径最大,为6.88mm;16S rDNA全序列鉴定显示,菌株DSP6与芽孢杆菌属Bacillus axarquiensis相似性为100%,表明菌株DSP6为Bacillus axarquiensis。

Isolation and Identification of Endogenetic Bacteria and Screening of Their Antagonistic Bacteria in Garlic

This test exploit the conventional methods of separation of the garlic bulb for bacteria,and the antagonistic experiment on plate and flat-panel coating on the separation of endophyte antagonist for the study on antibacterial as well as the 16S rDNA sequences to identify strains of antagonism.The result showed:separated 19 bacterial strains from the garlic bulb,and 10 strains could inhabit more than two plant pathogenic fungi,whose ratio is 52.6%,The inhibition of DSN7 on tomato early blight was the most obvious,which inhibition zone of radius was up to 13 mm;17 strains showed inhibition on at least one of the five pathogenic bacteria,whose ratio was up to 89.5%,and the inhibition zone of DSP3 on Escherichia coli was the most obvious,which was up to 10 mm;DSP6 particularly on trial for the 9 kinds of pathogens has a strong inhibitory effect,and the average radius of the largest inhibition zone is 6.88 mm.The 16S rDNA sequence alignment of DSP6 showed that its similarity was 100% with Bacillus axarquiensis,so strain DSP6 was identified as Bacillus axarquiensis.