Effects of cell suspension and cell·free culture filtrate of Pseudomonas aeruginosa in the control of root rot-root kont disease complex of tomato (Lycopersicon esculentum Mill.)

摘要

The plant growth-promoting rhizobacterium Pseudomonas aeruginosa strain IE-6 was tested for antagonistic activity towards Meloidogyne javanica , the root-knot nematode and soilbome root-infecting fungi viz., Macrophomina phaseolina , Fusarium solani and Rhizoctonia solani under laboratory and greenhouse conditions. Cell-free culture filtrate of the bacterium caused significant reduction in egg hatching of M.javanica and inhibited radial growth of fungi in vitro . Cell-free culture filtrate also caused lyses in mycelium of F.solani . Under greenhouse conditions, soil drenches with the aqueous cell suspension or cell-free culture resulted in a considerable reduction in nematode population densities in soil and subsequent root-knot development due to M.javanica . In addition to nematode control, rhizobacterium application also inhibited root-infection caused by soilborne root~infecting fungi with significant enhancement of growth of tomato seedlings.