【摘要】 松材线虫病（pine wilt disease,PWD）严重威胁中国松林生态健康，利用微生物资源开展生物防治是绿色防控的重要途径。本研究结合形态学观察与16S rDNA序列分析，对油松Pinus tabuliformis Carrière根际土壤细菌RhsP27进行鉴定；研究该菌株对松材线虫Bursaphelenchus xylophilus(Steiner&Buhrer)Nickle的影响和对松材线虫病的防治效果。结果表明，Rhs-P27的16S rDNA序列与绿针假单胞菌Pseudomonas chlororaphis(Guignard&Sauvageau)Bergey的同源性达98%以上，因此将其鉴定为绿针假单胞菌。Rhs-P27发酵菌悬液（Bacterial fermentation suspension,BFS）和发酵滤液原液（Bacterial fermentation filtrate,BFF）对松材线虫均表现出极强的毒杀活性，经这两种液体处理后的线虫繁殖系数分别是-0.41和0.79，产卵量约为对照的0.01和0.03倍；经油红O染色发现，Rhs-P27可破坏松材线虫体内的脂滴形态，使其粒径显著减小。盆栽试验对Rhs-P27的防治效果评估表明，使用Rhs-P27发酵菌悬液进行预防性注干处理，能有效减轻松材线虫病的症状，接种线虫后35 d的防效可达54.17%；松苗体内的线虫密度显著降低，仅为对照的0.41倍，且该处理诱导油松苗体内过氧化氢酶（catalase,CAT）、多酚氧化酶（polyphenol oxidase,PPO）、超氧化物歧化酶（superoxide dismutase,SOD）和苯丙氨酸解氨酶（phenylalanine ammonia-lyase,PAL）的活性提升。本研究揭示了绿针假单胞菌Rhs-P27在松材线虫病防控中具有显著的生物防治潜力，可为该病害高效绿色防控技术研究提供理论基础和菌种资源。更多还原

【Abstract】 Pine wilt disease(PWD) poses a serious threat to the ecological health of pine forests in China. Utilizing microbial resources for biological control represents an important approach for its environmentally friendly management. In this study,a bacterial strain Rhs-P27,isolated from the rhizosphere soil of Pinus tabuliformis Carrière,was identified based on morphological characteristics and 16S rDNA sequence analysis. Its effects on Bursaphelenchus xylophilus(Steiner & Buhrer)Nickle and its control efficacy against PWD were investigated. The results indicated that the 16S rDNA sequence of Rhs-P27 exhibited over 98%identity with that of Pseudomonas chlororaphis(Guignard & Sauvageau) Bergey,leading to its identification as P. chlororaphis.The impact of Rhs-P27 on B. xylophilus was manifested as potent nematicidal activity exhibited by both its bacterial fermentation suspension(BFS) and bacterial fermentation filtrate(BFF). After treatment with these liquids, the nematode reproduction coefficients were-0.41 and 0.79, respectively, and egg production was reduced to 0.01-fold and 0.03-fold of the control,respectively. Oil Red O staining revealed that Rhs-P27 disrupted the morphology of lipid droplets in B. xylophilus and significantly reduced their size. Pot experiments were conducted to evaluate the control efficacy of Rhs-P27 against PWD. The results indicated that preventive trunk injection with Rhs-P27 BFS effectively alleviated PWD symptoms,achieving a control efficacy of 54.17% at 35 days after inoculation. It also significantly reduced the nematode density in pine seedlings to 0.41-fold that of the control and induced increased activities of defense enzymes, including catalase(CAT), polyphenol oxidase(PPO), superoxide dismutase(SOD), and phenylalanine ammonia-lyase(PAL). This study reveals that P. chlororaphis Rhs-P27 possesses significant biocontrol potential against PWD,providing a theoretical foundation and microbial resource for the development of efficient and environmentally friendly control technologies.更多还原