Root-knot nematodes (Meloidogyne spp.) are the most destructive agricultural pests, which parasitize thousands of different plant species in the world. Using antagonistic bacteria can be a potential alternative to hazardous chemical nematicides. This study was conducted to evaluate the biocontrol activities of the bacteria isolated from vermicompost and earthworm against M. javanica in infected tomato plants. Seventeen bacteria were isolated from vermicompost and earthworm. Their antagonistic effects were tested against the root-knot nematode M. javanica in laboratory and in glasshouse experiments. In the preliminary screening test, 8 bacterial isolates significantly caused more than 50% decrease in reproduction factor (Rf) of the nematode on tomato plants. Six isolates with more than 60% reduction in the nematode Rf were selected and identified as follows: Lysinibacillus fusiformis C1, Bacillus megaterium C3, B. safensis VW3, Pseudomonas resinovorans VW4, Lysinibacillus sp. VW6, and Sphingobacterium daejeonense LV1 by 16S rRNA gene sequencing. The isolates B. megaterium C3, B. safensis VW3, P. resinovorans VW4, and L. fusiformis C1 inhibited the nematode egg hatching by 20–28%, and Lysinibacillus sp. VW6 and L. fusiformis C1 caused 15 and 20% mortality of the second-stage juveniles in vitro. In a glasshouse, the 6 bacterial isolates reduced the nematode Rf by 47–66%, and P. resinovorans VW4 was the most effective isolate. However, B. safensis VW3, B. megaterium C3, and L. fusiformis C1 had the best effect on plant growth. Most of the bacteria isolated from earthworm or vermicompost had nematicidal properties. This study provided empirical evidence of the nematicidal potential of isolates Lysinibacillus fusiformis C1, Pseudomonas resinovorans VW4, and Sphingobacterium daejeonense LV1 and the antagonistic activities of Bacillus megaterium C3 and B. safensis VW3 against Meloidogyne javanica.

中文翻译：

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ver虫和earth细菌分离物对感染番茄植物的根结线虫Meloidogyne javanica的生物防治潜力。

根结线虫（Meloidogyne spp。）是最具破坏性的农业害虫，其寄生于世界上成千上万的不同植物物种中。使用拮抗细菌可以替代危险的化学杀线虫剂。进行了这项研究，以评估从ver虫和earth中分离出的细菌对感染番茄植物中爪哇念珠菌的生物防治活性。从ver虫和earth中分离出十七种细菌。在实验室和温室实验中测试了它们对根结线虫爪哇线虫的拮抗作用。在初步筛选测试中，有8种细菌分离株显着导致番茄植物上线虫的繁殖因子（Rf）降低50％以上。选择了六个分离物，其线虫Rf降低了60％以上，如下所示：梭状芽孢杆菌C1，巨大芽孢杆菌C3，安全芽孢杆菌VW3，树脂假单胞菌VW4，Lysinibacillus sp。通过16S rRNA基因测序分析了VW6和大新菌Sphingobacterium daejeonense LV1。分离株巨大芽孢杆菌C3，安全芽孢杆菌VW3，树脂枯萎芽孢杆菌VW4和梭状芽胞杆菌C1对线虫卵的孵化抑制了20-28％，而Lysinibacillus sp。则被分离。VW6和L. fusiformis C1在体外导致15％和20％的第二阶段少年死亡。在温室中，这6种细菌分离株使线虫的Rf降低了47-66％，而P. resinovorans VW4是最有效的分离株。但是，安全芽孢杆菌VW3，巨大芽孢杆菌C3和梭形芽孢杆菌C1对植物的生长效果最好。从earth或ver虫中分离出的大多数细菌具有杀线虫特性。这项研究提供了经验的证据，证明了梭状芽孢杆菌C1假单胞菌，树脂假单胞菌VW4和大新Sphingobacterium daejeonense LV1的杀线虫潜力，以及巨大芽孢杆菌C3和安全芽孢杆菌VW3对抗爪哇根结线虫的拮抗活性。