PECTIC ZYMOGRAMS AS CRITERIA IN TAXONOMY OF RHIZOCTONIA

The extracellular pectic enzymes produced by members of the Ceratobasidiaceae were examined by Polyacrylamide slab gel electrophoresis. Cultures included species of Aquathanatephorus, Ceratobasidium, Pseudopapulaspora, Rhizoctonia and Waitea, as well as anastomosis grouped cultures of Ceratobasidium and Thanatephorus. Zymograms were reproducible, little influenced by cultural conditions, and provided, in a permanent record, a means for comparison of isolates. Correlations were found between zymogram patterns and anastomosis groups and their subgroups that have been recognized by morphology and pathology. Zymogram evidence supported some reported inter-relationships, such as between R. cerealis, AG-D and CAG-1. A relationship was found between AG-K and CZG5, also between fusion group E of Richter & Schneider, CAG6, AG-E and R. muneratii. The pectic zymogram method gave promise of aiding practical recognition of species in the complex. © 1990, British Mycological Society. All rights reserved.