Meloidogyne enterolobii is a soil-borne disease that seriously harms crop production in tropical areas, and the agricultural losses caused by it are incalculable every year. For the control of root-knot nematodes, the traditional physical and chemical control methods have some disadvantages, while biological control is environmentally friendly and safe for people and livestock, so it has gradually become a research hotspot. This study used the impregnation method to screen strains with killing activity against the second instar larvae of M. enterolobii. The fermentation conditions and treatment time of the screened highly active strains were optimized. The strains were identified using 16S rRNA sequencing as well as physiological and biochemical methods, and growth promoting characteristics were analyzed. The research results indicated that the nematicidal activity of the fermentation supernatant of BWLY1PSB-1, BWLY2X-4 and BWLY3X-11 were more than 65%. Through morphological, physiological and biochemical characteristics, and molecular biology identification, BWLY1PSB-1, BWLY2X-4 and BWLY3X-11 were identified as Staphylococcus pateuri, Bacillus methylotrophicus and Bacillus sp., respectively; The nematicidal activity of the fermentation supernatant of each strain could reach the maximum after 24 h treatment of nematodes, and the optimal fermentation medium was LB medium, and the nematicidal activity of the supernatant reached relatively high when cultured for five days. The research results on the growth promoting characteristics of thee strains indicated that BWLY1PSB-1 had the ability to produce iron carriers and IAA, while BWLY2X-4 and BWLY3X-11 had the ability to produce proteases, cellulases, iron carriers, and IAA. The preliminary screening of excellent strains that can effectively control plant root-knot nematodes and have rowth promoting characteristics would enrich the microbial resources for the biological control of plant root-knot nematodes.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |