Biosystematic Studies on Phlebia Acerina, P. Rufa, and P. Radiata in North America

ABSTRACT

Three closely related species, Phlebia rufa, P. acerina, and P. radiata, were analyzed with molecular, morphological, genetic, and physiological methods. Emphasis was placed on the phenotypically similar taxa P. rufa and P. acerina. Phlebia acerina is common and widely distributed in North America, but P. rufa occurs only in Washington, Oregon, and British Columbia. Although often considered conspecific, P. acerina and P. rufa are intersterile. In addition, differences in basidioma and cultural traits support their separation. At the molecular level, these species differ slightly in sequence of an internal transcribed spacer of the nuclear ribosomal DNA repeat and a part of the large mitochondrial rRNA gene. Restriction maps of the small mitochondrial rRNA gene and flanking regions provide further evidence that the species are distinct but closely related. This report includes basidioma and cultural descriptions of both species. Phlebia radiata is genetically distinct but shares many morphological and molecular traits with P. acerina and P. rufa. Cladistic analyses of molecular data showed that the three taxa are closely related relative to the outgroup taxa P. ludoviciana and P. subochracea.

Key Words:

• Corticiaceae
• internal transcribed spacer
• mitochondrial rRNA gene
• mating tests