SR13-2菌株是前期从种植莴苣的土壤中分离获得的对致病疫霉菌丝生长和孢子萌发有强烈抑制作用的拮抗细菌,为进一步了解其生物学特性以及防治马铃薯晚疫病的潜力,本试验依据其培养特征、生理生化特性及16S r DNA序列对该菌株进行了鉴定,并测试了其菌液在离体马铃薯组织上的防病效果。结果显示该菌株属于深红沙雷氏菌(Serratia rubidaea),菌液在马铃薯块茎切片上对晚疫病的预防效果可达91.83%,治疗效果可达83.33%,显著优于甲霜灵锰锌以及其他几株拮抗细菌,在马铃薯离体叶片上也获得了相似的结果。这表明SR13-2菌株在马铃薯晚疫病防治方面有较大潜力。
[ Objective ] The paper was to screen bacterial strain with significant antagonistic effect against Phytophthora infestans, so as to provide basis for further development and utilization of antagonistic bacteria to inhibit P. infestans and control potato late bright. [ Method] Plate dual culture and filter paper method were used to determine the inhibition effect of strains in vivo, fermentation broth and bacterial liquid of 61 strains against P. infestans and the resistance-induction effect of SR13-2 strain. [ Result] The inhibition rate of 24 strains among 61 tested strains against mycelial growth of P. infestans was greater than 60%, and the inhibi- tion effect of HT-6 strain was the strongest with the inhibition rate of 89.92%. However, fermentation broth of all tested strains had no significant inhibition effect against P. infestans, while the inhibition effect of bacterial liquid of most strains was significantly higher than strain in vivo; the inhibition effect of $34-1 strain was the strongest with inhibition rate of 91.50%. The bacterial liquid of SR13-2 strain was found to have significant resistance-induction effect with protective rate of 60%. [ Conclusion] The inhibition effect of strains in vivo and fermentation broth of antagonistic strains S34-1 and SR13-2 had no relationship with each other, while bacterial liquid had great application potential in controlling potato late bright.
