马铃薯疮痂病菌Streptomyces scabies拮抗细菌筛选及鉴定

Screening and Identification of Antagonistic Bacteria of Streptomyces scabies

为获得对马铃薯疮痂病菌(Streptomyces scabies)具有拮抗效果的细菌菌株,从黑龙江省齐齐哈尔市克山农场马铃薯疮痂病发病地块健康植株根际土壤中分离得到181株细菌菌株,采用平板对峙生长法和牛津杯试验法对分离得到的菌株进行初筛和复筛,获得1株对S. scabies具有明显拮抗效果的菌株BKS51,抑菌圈直径达到37 mm,盆栽防效达到81.0%。对BKS51进行形态特征、生理生化特征测定以及16S rRNA、gyrB基因序列分析,并进行抑菌谱测定。结果表明,菌株BKS51的菌落为圆形、乳白色、不透明,表面有褶皱状凸起,边缘不整齐,菌体杆状、革兰氏阳性菌,硝酸还原反应呈阳性、葡萄糖发酵反应及MR反应呈阴性,结合16S rRNA和gyrB基因序列分析结果,将其鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。BKS51对多种植物病原菌均具有抑制效果,其中对玉米圆斑病菌(Bipolaris zeicola)和水稻胡麻斑病菌(Bipolaris oryzae)的抑制率较高,分别达到67.2%和62.4%。

In order to obtain strains that have antagonistic effects on Streptomyces scabies,181 bacterial strains were isolated from the rhizosphere soil of healthy plants in the potato scab-infected plot of Keshan Farm in Qiqihar City,Heilongjiang Province. The flat plate stand-off growth method and the Oxford cup test were used to screen and re-screen the isolated strains,and a strain BKS51 with obvious antagonistic effect on S. scabies was obtained,with a bacteriostatic diameter of 37 mm,and the potted plant control effect reached 81. 0%. The morphological characteristics,physiological and biochemical characteristics of BKS51 were determined,16 S rRNA and gyrB gene sequences were analyzed,and the antibacterial spectrum was determined. The results showed that the colony of strain BKS51 was round,milky white,opaque,with fold-like protrusions,irregular edges. The strain was rod-shaped,and gram-positive,nitric acid reduction reaction was positive,and glucose fermentation reaction and MR reaction were negative.Combined with sequence analysis results of 16 S rRNA and gyrB,it was identified as Bacillus amyloliquefaciens. BKS51 had an inhibitory effect on a variety of plant pathogens,among them,the inhibition rates on Bipolaris zeicola and Bipolaris oryzae were higher,reaching 67. 2% and 62. 4%respectively.