Protection of Pseudomonas fluorescens against the Root-Knot Nematode, Meloidogyne incognita; Role of Enzyme-induced Resistance in Eggplant

摘要

A Pseudomonas fluorescens culture was applied at different dilutions to attempt to induce resistance in eggplant (Solanum melongena L.) cv. 'Baladi' against the root-knot nematode, Meloidogyne incognita. The efficacy of this culture, when applied as asoil drench or root dip, was compared with inoculated non-treated plants under greenhouse conditions. P. fluorescens was able to reduce nematode parameters at all dilutions and in both types of application. The S/2 dilution (10~8 CFU/ml/2) was the mosteffective in reducing nematode reproduction as measured by the number of developmental stages, galls, egg masses, females and larvae/pot (percentage nematode reduction was 66, 68, 63, 74 and 72%, respectively) when treated as a soil drench compared to the untreated control inoculated with M. incognita only. This was followed by P. fluorescens at a concentration of S/10 (10~8 CFU/ml/10) which significantly reduced the same parameters by 61, 58, 55, 63 and 32%, respectively compared to control inoculatedwith M. incognita only. These treatments (S/2 and S/10) were higher than those treated by root dip in most cases. Also, plant growth criteria improved in treated plots compared to controls. The activity of three enzymes (peroxidase, polyphenol oxidase and chitinase) increased in treated plants exposed to S/2, S/10 and S/20 compared to the inoculated non-treated control. P. fluorescens thus induced resistance in eggplant against M. incognita.