Molecular determination of genetic variation in Pisolithus isolates from a defined region in New South Wales, Australia

Sixty-two isolates of Pisolithus were obtained from a carpophore population collected from a 90-km(2) area of New South Wales, Australia. Random amplified polymorphic DNA (RAPD) analysis was used initially to screen isolates for variation, and restriction fragment length polymorphism (RFLP) analysis of the internal transcribed spacer (ITS) region and ITS sequence analysis were subsequently performed on selected isolates. ITS-RFLP and ITS sequence analysis indicated that two isolates (LJ07 and WM01) from different sites were considerably different from all other isolates, a strict consensus tree generated by bootstrap analysis of sequence data strongly suggesting that isolates LJ07 and WM01 represent a separate Pisolithus species. Although the general morphology of carpophores and basidiospores of the majority of collected isolates was consistent with previous descriptions of P. tinctorius (Pers.) Coker and Couch, basidiospore characteristics suggest that isolates LJ07 and WMO1 might represent a Pisolithus species distinct from P. tinctorius and the previously described Australian species, P. microcarpus (Cooke & Massee) G. Cunn.