ARBUSCULAR MYCORRHIZA TECHNOLOGY APPLIED TO MICROPROPAGATED PRUNUS-AVIUM AND TO PROTECTION AGAINST PHYTOPHTHORA-CINNAMOMI

Two species of arbuscular mycorrhizal (AM) fungi (Glomus intraradices, Glomus caledonium) introduced during post vitro acclimatization were tested for infection development and growth effects in Prunus avium, a fter transplantation into two types of disinfected or undisinfected ne utral soils. Endomycorrhizal plants grew better than nonmycorrhizal pl ants in both disinfected soils. Growth improvements by either fungus w ere related to a high level of mycorrhizal colonization. Mycorrhizal e ffects on P avium plants and mycorrhiza development depended on the so il type. In undisinfected soils containing an infective but inefficien t AM fungal population, growth of Prunus was improved by preinoculatio n with effective AM fungi adapted to the soil type. Moreover, clonal v ariations in AM development and mycorrhizal responsiveness to Glomus m osseae were observed in three P avium clones. The bioprotective effect of AM was shown in one clone where the presence of G mosseae eliminat ed the negative impact of Phytophthora cinnamomi on root growth.