Ectomycorrhization of Acacia holosericea A. Cunn. ex G. Don by Pisolithus spp. in Senegal: Effect on plant growth and on the root-knot nematode Meloidogyne javanica

The ectomycorrhization of Acacia holosericea with fungi isolated in Senegal (belonging to the Pisolithus genus) and their effect on Meloidogyne javani ca have been studied. In 100 tree plantations of Eucalyptus camaldulensis, Casuarina equisetifolia, Acacia mangium and A. holosericea, 33 fruiting bod ies of the ectomycorrhizal fungus Pisolithus were collected and cultured un der axenic conditions. Only four fungal isolates have induced the formation of typical ectomycorrhizae with A. holosericea under axenic conditions. On e of these, COI 024, increased plant development under glasshouse condition s and decreased the multiplication of the root-knot nematode Meloidogyne ja vanica. The mechanisms involved in these interactions and the potential use of the ectomycorrhizal symbiosis in agroforestry programs are being discus sed.