Some aspects of the biology of the fungal symbiont of Sirex noctilio

Abstract

Studies of the cultural characteristics on artificial media of the fungal symbiont of Sirex noctilio F. indicate that in Australia only one fungus is involved in the association. A medium containing 20 p.p.m. o-phenylphenol was found suitable for the isolation of the Sirex fungus. Histological studies confirmed that the Sirex fungus develops in wood only as vegetative hyphae. Ray parenchyma cells were killed in advance of the growing hyphae, which suggested that a toxin was produced by the fungus. Comparisons of growth in agar culture, of fructifications produced on wood blocks, and of starch gel electrophoresis protein patterns indicated that the Sirex fungus is probably a strain or variety of Arnylostereum chailletii (Fr.) Boidin.