The mycorrhizal relationships between pines and two edible species ofLactariussect.Dapeteswere investigated by optimizing the experimental conditions of mycelial growth and of mycorrhizal colonization of pine seedlings. In vitro mycelial growth ofLactarius deliciosusandL. sanguifluuswas improved on a buffered medium containing glucose, amino acids, and vitamins. Two methods of mycorrhization of pines withLactarius deliciosuswere tested. The mycorrhizal colonization was rapid and intense under non-aseptic conditions with a low nutrient supply and without exogenous glucose. A positive influence of mycorrhizal colonization onPinus sylvestrisgrowth was subsequently observed. Under axenic conditions and with a high nutrient supply, mycorrhization was stimulated at 10 g/L of exogenous glucose, irrespective of the phosphorus concentration. At high phosphorus level (1 mM) and 0.1, 1.0, or 10.0 g/L glucose, growth ofPinus sylvestriswas reduced by inoculation. Stability and development ofPinusspp./Lactarius deliciosussymbioses were assayed in a climatic chamber using containers filled with a synthetic substrate. Over a 2-year culture period, the root systems of the pine seedlings were heavily colonized byLactarius deliciosus. One year following inoculation,Lactarius deliciosusfruit-body primordia appeared associated withPinus sylvestrisseedlings. Six months later, two mature basidiomata were obtained. This is the first report of soilless fruit-body formation of this edible mushroom.Key words: ectomycorrhiza, inoculation,Lactarius deliciosus,Lactarius sanguifluus,Pinus, wild edible mushrooms.