Molecular characterization of Pleurotus eryngii varieties occurring in Italy

The Pleurotus eryngii species complex is an economically important group which includes several closely related varieties, whose genetic discrimination is still not clear. One hundred and ten Italian strains of Pleurotus eryngii belonging to the varieties elaeoselini, eryngii, ferulae and thapsiae and P. nebrodensis were analysed by sequencing two housekeeping genes (ef1-a and rpb2), in order to find molecular markers for the identification of different varieties. Sequence analysis of partial ef1-a and rpb2 genes, allowed identification of some conserved nucleotide positions within each variety but variable among var. elaeoselini, var. eryngii, var. ferulae, var. thapsiae and P. nebrodensis, allowing their discrimination. Phylogenetic analysis from the data of the two genes data set showed that var. elaeoselini, var. thapsiae, var. ferulae and var. eryngii are closely related to each other, and confirm P. nebrodensis as a separate clade.