Phylogenetic relationships between Tuber pseudoexcavatum, a Chinese truffle, and other Tuber species based on parsimony and distance analysis of four different gene sequences.

Phylogenetic relationships between Tuber pseudoexcavatum and other Tuber species were investigated by studying the sequences of four genes: 5.8S-ITS2, beta-tubulin, protein kinase C and elongation factor 1alpha. The four phylogenetic trees allowed to differentiate the black truffle clade, composed of two subclades, one comprising the Asian black truffles (T. indicum, T. sinense, T. himalayense) and the Perigord black truffle (T. melanosporum), the second comprising T. pseudoexcavatum and T. brumale. These two subclades diverged relatively early. We propose a common ancestor, located between Europe and China, to all the black truffles. The T. brumale/pseudoexcavatum subclade would have started to diverge and migrate first, T. brumale towards Europe through a northern route and T. pseudoexcavatum towards China. Later the T. melanosporum subclade would have started to migrate through the same route, T. melanosporum towards Europe and T. indicum towards China, leading to vicariant species.