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Résumé :
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As in 1994, all the experiments, in laboratory conditions or in nursery or field conditions, started as planned. We also continue to use nursery or field experiments which have been settled during the negociatin phase of the actual contract or just before. The results of this second year of work were scientifically very promosing. We now have the tools to better understand the relationships between micro-organisms, rhizogenesis processes and mycorrhizal infection. In 1994, if it was relatively easy to identify a specific strain by PCR typing in pure culture or in association with the host in nursery conditions, it was much more difficult to use this method in field situation. In 1995, we have solved this problem and we are now able to identify ectomycorrhizal strains in field situations. The final objective which is to associate clones selected because of their superior form and vigour or wood quality, with superior strains of ectomycorrhizal fungi or bacteria seams still feasible. We have solved several difficulties and now we are able to get a good mycorrhizal infection in in vitro conditions, except for oak, and in non axenic conditions, during or after the rooting phase of the cuttings. The common experiment established on Douglas fir in three locations, Les Barres, Nancy and Cabrils to try to solve the problems of mycorrhizal infection during the rooting phase was a complete success. We almost always get an improvement of the performances of the cuttings during the nursery phase. The long term field experiments are for the moment, disappointing. We have observed no improvement of the performances of the cuttings by microbial inoculation in field situation.
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