Root-knot nematode disease, caused by Meloidogyne spp., is one of the most serious soil-borne diseases for vegetable industry worldwide. A total of 448 endophytic bacteria isolates were obtained from root nodules and screened for the potential biological control activity against M. incognita in the field and pot under the greenhouse conditions. Strain Sneb1997 and Sneb2001 were screened with high biocontrol efficacy against M. incognita and identified as Pseudomonas protegens and Serratia plymuthica by morphology analysis, physiological biochemical test and biomolecular assay, respectively. Furthermore, 24 h after treatment, P. protegens Sneb1997 and S. plymuthica Sneb2001 showed high lethal effect on the second stage juveniles of M. incognita with mortality rate were 87.78% and 92.67% and inhibited egg hatching significantly (P < 0.05) with the hatch inhibition rate of 87.76% and 82.86%, respectively. Meanwhile, P. protegens Sneb1997 was effective in improving seed germination and S. plymuthica Sneb2001 did not affect seed germination. Then, the stability and efficiency of M. incognita control by P. protegens Sneb1997 and S. plymuthica Sneb2001 was further assessed in greenhouse and in the field in 2018 and 2019. The results of pot experiment showed that the metabolites of P. protegens Sneb1997 and S. plymuthica Sneb2001 both significantly (P < 0.05) decreased the number of root galls and egg masses of root and P. protegens Sneb1997 significantly (P < 0.05) promoted the growth of tomato plants. The results of field experiments demonstrated that two tested strains could significantly (P < 0.05) reduce gall index and significantly (P < 0.05) increased the tomato plant biomass. Confocal microscopy and colonization assay demonstrated that both endophytes could colonize in tomato roots and stems with a high density for a long period of time. In summary, our results demonstrate that endophytic P. protegens Sneb1997 and S. plymuthica Sneb2001 can be used as potential biological control agents to control root-knot nematode disease.

由根结线虫（Meloidogyne spp。）引起的根结线虫病是全世界蔬菜工业中最严重的土壤传播疾病之一。从根瘤中获得了总共448种内生细菌分离株，并筛选了在温室条件下田间和盆栽中对隐杆线虫的潜在生物防治活性。应变Sneb1997和Sneb2001与针对高生物防治功效进行了筛选南方根结线虫和鉴定为保护假单胞菌和普城沙雷分别形态分析，生理生化试验和生物分子测定法中，。此外，在治疗后24小时，蛋白假单胞菌Sneb1997和S. plymuthicaSneb2001显示高致死效应上的第二阶段juveniles南方根结线虫与死亡率分别为87.78％和92.67％，并且抑制蛋显著（阴影P  <0.05），用分别87.76％和82.86％，该舱口抑制率。同时，P。protegens Sneb1997可有效改善种子发芽，而S. plymuthica Sneb2001则不影响种子发芽。然后，稳定性和效率南方根结线虫控制由P. protegens Sneb1997和普城沙雷菌Sneb2001在温室，并在2018年和2019年盆栽试验的结果领域进一步评估表明，代谢物P. protegensSneb1997和S. plymuthica Sneb2001均显着（P  <0.05）减少了根gall和卵子根的根瘤菌数量和蛋白质质量Sneb1997显着（P  <0.05）促进了番茄的生长。田间试验结果表明，两种被测菌株均可显着（P  <0.05）降低胆汁指数，显着（P  <0.05）增加番茄的生物量。共聚焦显微镜和定植分析表明，两种内生菌都可以长时间在高密度的番茄根和茎中定植。总而言之，我们的结果表明内生体育蛋白Sneb1997和脓链霉菌Sneb2001可用作潜在的生物防治剂来控制根结线虫病。