Fine Structure of Armillaria Mellea Hyphae

Armillaria mellea(Vahl ex Fr.) Rummer is an important pathogen, causing “shoe-string”root rot of forest trees; its impact on coniferous plantations in Newfoundland has been realized only recently. Growing interest in the fungus and the disease has led to research on the finer aspects of the pathogen. Attempts to elucidate the ultrastructure of the rhizomorph, have been made recently by Motta and that of the hyphae by Berliner and Duff. The present investigation includes certain aspects of the fine structure of young hyphae, hitherto not dealt with. The fungus was isolated from mycelial fans present under the bark of infected roots ofPicea glauca(Moench) Voss and maintained on 2% Malt extract agar. Peripheral hyphae from 22 days old culture were scraped off from the surface of the medium and fixed in a mixture of paraformaldehyde-glutaraldehyde in Sorensen's buffer pH 7.2. This was followed by post osmication in 1% 0s04 and subsequent Epon embedding.