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为筛选出对番茄枯萎病和青枯病有较好防效的生防菌,采用平板对峙法,以番茄枯萎病菌Fusarium oxysporum和番茄青枯病菌Ralstonia solanacearum为靶标菌,从江苏沭阳、宿迁、溧水及内蒙古海拉尔分离到的2 062株细菌菌株中筛选拮抗菌株,并采用平板对峙法、拮抗菌液灌根法、分子生物学方法进行拮抗物质检测、盆栽试验及种属鉴定。结果表明:从2 062株细菌中共筛选到21株对番茄枯萎病和青枯病具有很强拮抗作用的菌株,均能分泌蛋白酶,具有解磷作用;不能分泌几丁质酶和纤维素酶,仅4株细菌能分泌嗜铁素。拮抗细菌SY290对番茄枯萎病和番茄青枯病防效最高,分别达到74.2%和75.0%,SQ728和LS536次之,但防效均大于60%。结合各菌株形态特征、16S r DNA与gyr-B序列分析结果,菌株SY177、SY290和SQ728鉴定为解淀粉芽胞杆菌Bacillus amyloliquefaciens,菌株LS536为枯草芽胞杆菌B.subtilis。
In order to screen out the biocontrol microbes with good control effect on Fusarium wilt and bacterial wilt of tomato, the fusarium oxysporum Fusarium oxysporum and Ralstonia solanacearum were used as the target bacteria. The samples were collected from Shuyang, Suqian, Lishui And antagonistic strains were screened from 2 062 bacterial strains isolated from Hailar, Inner Mongolia. The antagonistic strains were tested by plate confrontation method, antagonistic bacterium solution irrigation and molecular biology methods, pot experiment and species identification. The results showed that 21 strains of strains with strong antagonistic activity against Fusarium wilt and bacterial wilt of tomato were screened from 2 062 strains of bacteria, both of which secreted protease and had the effect of phosphorus solubilization. They could not secrete chitinase and cellulase, Only 4 strains of bacteria can secrete mastoid. Antagonistic bacterium SY290 had the highest control effect on tomato blight and tomato bacterial wilt, reaching 74.2% and 75.0% respectively, followed by SQ728 and LS536, but the control effect was over 60%. According to the morphological characteristics of each strain, 16S r DNA and gyr-B sequence analysis results showed that the strains SY177, SY290 and SQ728 were identified as Bacillus amyloliquefaciens and LS536 was B. subtilis.