Han Shengjie, Zhao Leilei, Pan Min, Zhang Hongyan, Gu Xiaofeng, Zheng Lei, Tan Jiajin
College of Forestry and Grassland, Collaborative Innovation Center of Modern Forestry in South China, Nanjing Forestry University, Nanjing, China.
Jurong City Forestry Pest Quarantine Control Station, Zhenjiang, China.
Pest Manag Sci. 2025 Sep;81(9):5630-5648. doi: 10.1002/ps.8918. Epub 2025 May 23.
Pine wilt disease (PWD), caused by Bursaphelenchus xylophilus (PWN), leads to severe ecological and economic losses. Current control methods rely on chemical nematicides, which pose environmental and health risks and have led to PWN resistance, reducing their field efficacy. A green and effective strategy is urgently needed.
A highly effective nematicidal strain, SD30, was screened. Its fermentation broth achieved a nematicidal rate of 100% after 12 h and the same result after 24 h for the filtrate. The bacterial suspension showed a 76.60% nematicidal rate after 48 h. SD30 was identified as Bacillus thuringiensis through morphological and molecular methods. In indoor efficacy tests on Pinus massoniana, the bacterial suspension exhibited a control efficacy of 54.74%, outperforming both the fermentation broth and filtrate. When applied 7 days before inoculation, the bacterial suspension achieved a 67.00% control efficacy, more effective than when applied 3 days before, on the day, or after inoculation. The highest control efficacy (52.00%) was observed at a concentration of 3 × 10 cfu mL, with efficacy decreasing at higher dilutions. Indoor control efficacy on Masson pine and larch was 67.74% and 73.68%, respectively, with better results on larch. In safety evaluations, Bt SD30 showed no pathogenicity to tobacco and alfalfa, was sensitive to six antibiotics, exhibited weak hemolytic activity, and contained the virulence genes nheB, nheC and entFM.
This study screened out Bt SD30 from larch, which demonstrates strong nematicidal activity and holds potential for biocontrol applications against pine wilt disease. © 2025 Society of Chemical Industry.
由松材线虫（PWN）引起的松树萎蔫病（PWD）会导致严重的生态和经济损失。当前的防治方法依赖于化学杀线虫剂，这带来了环境和健康风险，并导致PWN产生抗性，降低了它们在田间的防治效果。迫切需要一种绿色且有效的策略。
筛选出了一种高效杀线虫菌株SD30。其发酵液在12小时后杀线虫率达到100%，滤液在24小时后也达到相同结果。细菌悬浮液在48小时后杀线虫率为76.60%。通过形态学和分子方法将SD30鉴定为苏云金芽孢杆菌。在对马尾松的室内药效试验中，细菌悬浮液的防治效果为54.74%，优于发酵液和滤液。在接种前7天施用时，细菌悬浮液的防治效果达到67.00%，比在接种前3天、接种当天或接种后施用更有效。在浓度为3×10⁸ cfu/mL时观察到最高防治效果（52.00%），稀释度更高时效果降低。对马尾松和落叶松的室内防治效果分别为67.74%和73.68%，对落叶松的效果更好。在安全性评价中，Bt SD30对烟草和苜蓿无致病性，对六种抗生素敏感，溶血活性较弱，并且含有毒力基因nheB、nheC和entFM。
本研究从落叶松中筛选出Bt SD30，其表现出强大的杀线虫活性，在松树萎蔫病生物防治应用方面具有潜力。© 2025化学工业协会。
