Characterization of New Zealand isolates of Chondrostereum purpureum with regard to morphology, growth, pathogenicity and RAPD banding patterns

Isolates of Chondrostereum purpureum were characterised on malt agar by rap id growth of white, flat, velvety to cottony mycelium and formation of yell ow fruitbody crusts with apiculate basidiospores. The presence of cystidia was diagnostic, but not a reliable taxonomic character. Above 33 degrees C isolates exhibited a differential growth response and only three failed to grow following 20 d incubation at 36 degrees. Tolerance of high temperature was not correlated with RAPD banding patterns nor geographic origin. All i solates were pathogenic to willow, poplar and apple regardless of their ori ginal host, locality or RAPD profiles. No zones of demarcation were observe d following infection of wounds by multiple isolates. RAPD banding patterns exhibited considerable diversity, enabling discrimination of isolates with single primers, and this was indicative of the extensive genetic diversity within the NZ population. No RAPD banding combinations specific to host sp ecies or locality were observed. An explanation is given for the wide disse mination of C. purpureum isolates throughout NZ.