COMANDINI, O. & PACIONI G.
Department of Environmental Science, via Vetoio, Loc. Coppito I-67100 L'Aquila. ITALY.
Ectomycorrhizas of silver fir (Abies alba Miller) were studied in two stands, one natural and one artificial, in Central Italy. A total of 25 mycorrhizal types were characterized. Analysis of macro- and microscopic features and matching of field-collected carpophores with associated mycorrhizas, brought to the identification of two new ectomychorrhizal types: Lactarius ichoratus (Batsch)Fr. and Tricholoma bufonium (Pers.:Fr.)Gillet. Lactarius ichoratus mycorrhizas are simple or monopodial-pinnate. They are characterized by a pseudoparenchymatous mantle with polygonal cells in the outer part, and a plectenchymatous mantle with loosing hyphae and laticifers in the inner part. Latex is white and turns light yellow with the use of KOH. Rhizomorphs have never been observed. This ectomycorrhizal type has features in common with other related Lactarius ectomycorrhizas such as those of L. subdulcis Bull.:Fr. and L. rubrocinctus Fr. Tricholoma bufonium ectomycorrhizas are monopodial-pinnate or irregularly-pinnate. The mantle surface is cottony with abundant pink-reddish rhizomorphs that in young samples have yellowish tones; the same colors are also present in the relative carphophores. The mantle is plectenchymatous in the outer and in the middle layers, transitional between plectenchymatous and pseudoparenchymatous in the inner one. Rhizomorphs are undifferentiated (type B) and are very similar to the ones present at the base of the relative carphophores. These ectomycorrhizal types are frequent both in the natural and in the artificial stands.