title: Peering into the Mediterranean black box:Lactifluus rugatusectomycorrhizas onCistus.
abstract: We describe the morpho-anatomical features of the ectomycorrhizas (ECMs) formed byLactifluus rugatusonCistus, a genus of about 20 species of woody shrubs typical of the Mediterranean maquis. The description ofL. rugatusmycorrhizas onCistusis the first ECM description of a species belonging toLactifluussubgen.Pseudogymnocarpi. The ECM identity was verified through molecular tools. Anatomically, the characteristic ofL. rugatusmycorrhiza is the presence of abundant, long "bottle-shaped" cystidia on mantle surface. Indeed, the overwhelming majority of milkcap mycorrhizas are acystidiate. This is the thirdLactarius/Lactifluusmycorrhiza to have been described associated withCistus, the others beingLactarius cistophilusandL. tesquorum. The phylogenetic distance between all these taxa is reflected by the diversity of the principal features of their ECMs, which share host-depending ECM features known forCistus,but are otherwise distinguishable on the host roots. Comparison ofLactifluus rugatusECM with those formed byL. vellereusandL. piperatusonFagusreveals elevated intrageneric diversity of mycorrhizal structures. Such a diversity is supported by analysis of ITS sequences of relevant species within EuropeanLactifluusspecies. Our study extends knowledge ofCistusmycorrhizal biology and confirms the informative value of mycorrhizal structures in understanding phylogenetic relationships in ECM fungi.
authors.affiliation: Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Leonardi
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, Monserrato (CA), Italy.
authors.forename: Ornella
authors.initials: O
authors.lastname: Comandini
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, I-09042 Monserrato (CA), Italy.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Rinaldi
keywords: Lactarius; Russulaceae; confocal laser scanning microscopy; maquis; molecular phylogeny