Characterization of mycorrhizal fungi of the genus Tulasnella (Tulasnellaceae, Basidiomycota) in the genus of orchids Bletia from Barranca del Cupatitzio Natural Reserve, Mexico

Abstract

The goal of this study was the identification of mycorrhizal fungi associated with three terrestrial orchids of the genus Bletia Ruiz & Pav.: B. roezlii Rchb. f., B. purpurata A.Rich., and B. punctata Lex., in Barranca del Cupatitzio Natural Reserve - Michoacán, México - . Thirty-nine strains were isolated and morphologically characterized. Nine strains were selected from the molecular analysis. Bletia punctata, an endemic species of Mexico, showed the lowest variability in mycorrhizal fungi. Morphological analysis showed that 39 isolated strains belong to the ‘Rhizoctonia-like fungal complex’. According with the tree of Euclidian distances generated by the analysis WARD, all isolates were included into four subgroups, all related to the genus Tulasnella J.Schröt - which belongs to the ‘Rhizoctonia-like fungal complex’?. Molecular and phylogenetic analysis of the nine selected strains corroborated the results of the morphological study: the sequences obtained were clustered in four subclades related to species of Tulasnella. Our results indicate that a single species of Bletia from a single locality can be associated with different species of mycorrhizal fungi, at least during the adult stage and that the combination of morphological and molecular analyses is a good tool to identify orchid mycorrhizal fungi.