College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing, 163319, China.
Keshan branch, Heilongjiang Academy of Agricultural Sciences, Keshan, 161606, China.
Arch Microbiol. 2022 Jul 14;204(8):483. doi: 10.1007/s00203-022-02989-5.
Potato scab is an important soil-borne disease that can significantly reduce the quality and economic value of potatoes. The purpose of this study was to isolate, screen and identify endophytic bacteria that have antagonistic and control effects on potato scab disease, and to determine the control effect and yield traits of the selected strains on potato scab disease in field conditions. A bacterial strain K-9 was isolated from the junction between scab spot and healthy epidermis of potato tuber. The K-9 strain was identified as Bacillus sp. through morphological, physiological and biochemical characterization, and 16S rDNA and gyrB gene sequence analysis. The diameter of the inhibition zone of strain K-9 against Streptomyces scabies on the YME plate was 3.82 cm. The K-9 strain could inhibit eight types of crop pathogens, with the highest inhibition rate (70.39%) against another soil-borne potato disease (potato black scurf). In the field test, the control effect of K-9 strain against potato scab was not significantly different from that of mixed bacteria or chemical agents, but the disease index and the scab index in the K-9 treatment were significantly lower than in the control. The potato yield in the K-9 treatment was 12.44% higher than the control. In summary, the K-9 strain can prevent not only potato scab, but also increase potato yield. Therefore, the endophytic bacterial K-9 strain may be a potential biological control agent.
马铃薯疮痂病是一种重要的土传病害，可显著降低马铃薯的品质和经济价值。本研究旨在从马铃薯疮痂病病斑与健皮交界处分离、筛选和鉴定对马铃薯疮痂病具有拮抗和防治作用的内生细菌，并在田间条件下测定所选菌株对马铃薯疮痂病的防治效果和产量性状。从马铃薯疮痂病病斑与健皮交界处分离得到一株内生细菌 K-9，通过形态学、生理生化特征及 16S rDNA 和 gyrB 基因序列分析，鉴定该菌株为芽孢杆菌属（Bacillus sp.）。在 YME 平板上，K-9 菌株对疮痂链霉菌的抑菌圈直径为 3.82 cm。K-9 菌株对 8 种作物病原菌均有抑制作用，对另一种土传马铃薯病害（马铃薯黑痣病）的抑制率最高（70.39%）。田间试验结果表明，K-9 菌株对马铃薯疮痂病的防治效果与混合菌或化学药剂处理无显著差异，但 K-9 处理的病情指数和疮痂指数显著低于对照。K-9 处理的马铃薯产量比对照提高 12.44%。综上所述，K-9 菌株不仅能防治马铃薯疮痂病，还能提高马铃薯产量。因此，内生细菌 K-9 菌株可能是一种有潜力的生物防治剂。
