Phellinus noxius: molecular diversity among isolates from Taiwan and its phylogenetic relationship with other species of Phellinus based on sequences of the ITS region

BACKGROUND: Analysis of phylogenetic relationship of 91 isolates of Phellinus noxius obtained from 46 plant species in Taiwan did not show distinct grouping based on ITS sequences. RESULTS: However, the ITS nucleotides showed 20 different kinds of variations including single nucleotide polymorphisms, deletion and insertion in ITS1 and ITS2, but none in 5.8 S. The Taiwanese isolates of P. noxius were dividable into long (type L), median (type M) and short (type S) groups based on ITS sequence length. Two isolates with identical ITS sequence belonged to types L. Type M with 72 isolates was further divided into 33 subtypes, while types S with 17 isolates was further divided into two subtypes. CONCLUSION: Phylogenetic analysis of ITS sequences among Phellinus species showed that isolates of P. noxius were in the same clade distinctly separated from other Phellinus species.