TYPE OF LIGHT AND FORMATION OF BASIDIOMATA OF TWO SPECIES OF EDIBLE ECTOMYCORRHIZAL MUSHROOMS ASSOCIATED WITH NEO-TROPICAL PINES AND THE DESCRIPTION OF BASIDIOMATA DEVELOPMENT

Ectomycorrhiza is a mutualistic symbiosis of paramount importance in the functioning of forest ecosystems. Therefore, inoculation with ectomycorrhizal fungi, particularly edible species, has gained enormous relevance in the production of forest trees with economic importance. However, due to technical difficulties for the cultivation of ectomycorrhizal basidiomata associated with their host trees, factors influencing basidiomata formation have not been fully understood. This study evaluated the effect of two light wavelengths on the production of basidiomata of two edible ectomycorrhizal mushroom species (Hebeloma leucosarx and Laccaria bicolor) associated with two neo-tropical trees, Pinus montezumae and Pinus greggii. The two fungal species evaluated are widely used as food and sold in traditional markets in México. In general, the type of light differentially influenced the basidioma formation of these fungi in association with host seedlings in greenhouse during six years. Increased basidioma formation of H. leucosarx was observed associated with trees growing in pots covered with yellow filters with a wavelength of ~590 nm compared with those covered with red filters with a wavelength of ~660 nm. Meanwhile, the opposite trend was observed in basidiomata of L. bicolor. The host tree species influenced the formation of basidiomata. Hebeloma leucosarx produced more basidiomata in association with P. montezumae than with P. greggii. In addition, a description of basidiomata formation from very young stages previous to senescence is provided for both mycobionts. To our knowledge, this is the first record of the effect of light wavelengths on the production of basidiomata of edible ectomycorrhizal mushrooms, demonstrating that this phenomenon is more complex than previously believed.