Combined Effect of Pseudomonas fluorescens and Arbuscular Mycorrhizal Fungi on Meloidogyne incognita Infecting Solanum melongena L

Abstract

Sole and consortium treatments of four isolates of Pseudomonas fluorescens (Pf<inf>1</inf>, Pf<inf>2</inf>, Pf<inf>9</inf> and Pf<inf>10</inf>) with arbuscular endomycorrhizal fungi (AMF) on root-knot nematode, Meloidogyne incognita (Ne) on eggplant (Solanum melongena L.) were evaluated. In general, the combined treatments by AMF and Pf isolates decreased significantly (P≤0.05) root-knot nematode as indicated by numbers of egg masses, eggs and galls per root system more than single treatments. Co-toxicity% for the two applied combined treatments of each bacterial isolate+ AMF, added at the same time with nematode (Ne) or added at 7 days before Ne inoculation, showed additive or synergistic interaction effects. The tested isolates increased significantly (p≤0.05) plant growth criteria according to the tested materials. The same isolates +AMF with Ne at the same time recorded less colonization percentage (35%), while 40% root colonization was achieved when added at 7 days before nematode inoculation. Also, when AMF alone was applied at 7 days before nematode inoculation, it caused the highest percentage of colonization (60%). It could be concluded that the consortium treatment with AMF and P. fluorescens significantly decreased M. incognita on eggplant more than single treatments.