ABSTRACT
Phylogenetic relationships among truffle species from Europe and China were investigated through parsimony analysis of the ITS sequences. Three major clades were obtained among the species analysed. The so-called white truffles appeared polyphyletic since Tuber magnatum was grouped with brown truffles and not with the other white species (T. maculatum, T. borchii, T. dryophilum, T. puberulum). The black truffles investigated in this study, T. brumale, T. melanosporum, T. indicum and T. himalayense, were grouped in an independent clade. The Périgord black truffle T. melanosporum and the Chinese black truffles T. indicum and T. himalayense, were very closely related. The delimitation of these species was estimated by a distance analysis on several isolates collected from different geographic areas. In spite of intraspecific variations of the internal transcribed spacers (ITS) sequences, T. melanosporum and the Chinese black truffles can be unambiguously attributed to distinct taxa.
Subject(s)
Ascomycota/classification , Ascomycota/genetics , DNA, Fungal/genetics , Phylogeny , China , DNA Restriction Enzymes/metabolism , DNA, Fungal/chemistry , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Europe , Molecular Sequence Data , Polymerase Chain Reaction/methods , Polymorphism, Restriction Fragment LengthABSTRACT
The ascal wall of Leptosphaeria senegalensis typically belongs to the bitunicate type; in its fin al state it comprises an exoascus separated from the endoascus by a clear space. The three-layered endoascus is formed of fibrillae whose most internal are accordion-like folded. The ascospores have a complex wall; from the interior to the exterior it comprises: an endospore, an irregularity thickened epispore, a perispore, and an ectospore thickened in a cap at the posterior end of the spore. The comparison of ascospores of two "real" Leptosphaeria (L. acuta et L. maculans) with those of L. senegalensis shows that the latter species must no longer be included in the genus Leptosphaeria.
