南方根结线虫生防菌X-20的鉴定及其作用机制研究
Identification and Mechanism of Strain X-20 for Biocontrol against Meloidogyne incognita
董海龙 1路平 1翟浩臻 1赵增旗 2王莉 3王建明 1徐玉梅1
作者信息
- 1. 山西农业大学植物保护学院,晋中 030801
- 2. 新西兰土地环境保护研究所,奥克兰1072
- 3. 山西省植物保护植物检疫中心,太原 030001
- 折叠
摘要
南方根结线虫是设施蔬菜上的重要植物病原物,但目前缺乏安全高效的生物防治措施.本研究从根结线虫罹病土壤中分离到一株生防菌X-20,其发酵液对南方根结线虫二龄幼虫校正死亡率达100％.通过形态学、生理生化特征和分子生物学方法将菌株X-20鉴定为荧光假单胞菌Pseudomonas fluorescens.菌株X-20发酵液处理南方根结线虫时,当处理浓度1mg/mL,虫体出现扭曲、僵直变化,内部组织分解;处理1h后,虫体波动频率降幅47.26％、头部摆动频率波动性变化、虫体弯曲频率成S型变化;处理24h后,二龄幼虫的体长减少4.68％,口针增加7.64％,透明尾长增加83.90％;J2虫体体液出现外渗,且电导率随着处理浓度的增大和时间延长而增加;发酵液甲醇提取物1 mg/mL处理虫体,6 h后糖含量比对照增加39.10％,甘油含量比对照高出66.67％,可溶性蛋白含量降低55.73％.由此可见,荧光假单胞菌X-20菌株代谢产物通过破坏根结线虫体壁及虫体内部结构,引起虫体液渗漏,扰乱虫体内糖类、脂类、蛋白类代谢,造成虫体死亡.
Abstract
Meloidogyne incognita is a major pathogen that affects vegetable crops,and currently,there are limited safe and efficient biological control options available.In this study,strain X-20 was isolated from soil where root-knot nematodes were present.When tested against second-stage juveniles(J2)of M.incognita,strain X-20 exhibited a mortality rate of up to 100％after 24 and 48 hours.The strain X-20 was identified as Pseudomonas fluorescens through various methods,including morphological,physiological,biochemical and molecular biological analysis.When 1 mg/mL fermentation broth of strain X-20 was used to treat J2 of M.incognita,the nematode body showed twisted and stiff changes,and the internal tissue decomposed.After 1 hour of treatment,the fluctuation frequency of the body decreased by 47.26％,the swing frequency of head and the bending frequency of the body also changed.After 24 hours of treatment,the body length of M.incognita J2 decreased 4.68％,while the stylet length and the hyaline tail length of M.incognita J2 increased by 7.64％and 83.9％,respectively.Meanwhile,the body fluids of M.incognita J2 leaked,and its conductivity increased with the increase of treatment concentration and time.After six hours treatment with 1 mg/mL methanol extract from fermentation broth,the sugar and glycerol content of J2 body increased by 39.10％,66.67％,respectively;While the soluble protein content of J2 body 55.73％decreased compared to the control.In conclusion,the metabolites produced by strain X-20 were found to cause body fluid leakage,disrupt the body wall and internal structure of root-knot nematodes,and affect the metabolism of sugars,lipids,and proteins,ultimately leading to the death of M.incognita.
关键词
荧光假单胞菌/代谢产物/南方根结线虫/防治效果/生防机理Key words
Pseudomonas fluorescens/metabolite/Meloidogyne incognita/control efficacy/biocontrol mechanism引用本文复制引用
基金项目
山西省中央引导地方科技发展资金(YDZJSX2021A033)
国家自然科学基金(31801958)
山西省高等学校优秀成果培育项目(2019KJ021)
山西省运城市基础研究项目(YCKJ-2021054)
出版年
2024
国家科技期刊平台
NSTL
万方数据