MORPHOLOGICAL FEATURES OF SYNTHESIZED ECTOMYCORRHIZAE OF ALNUS CRISP A AND A. RUGOSA*

Abstract

SUMMARYThe ability of two shrubby alders to form ectomycorrhizae with known species of fungus was investigated. Frankia-'moc\i\aX.ed seedlings oi Alnus crispa and Alnus rugosa were raised in growth pouches and inoculated with a pure culture inoculum of potential ectomycorrhizal fungi. Ten of the 46 species of fungi used formed ectomycorrhizae with both Alnus species. Only Alpova diplophloeus showed a well distributed Hartig net; others had a net only proximally, while others had none. These patterns are discussed in terms of more or less rapid Hartig net development. "The Hartig net was always confined to the epidermal layer of the root, never completely surrounding it. This situation appears to predominate in the Angiosperms. Colonization of young actinorhizae by Alpova diplophloeus led to the formation of ectomycorrhizal structures.

Natural 13 C abundance reveals trophic status of fungi and host-origin of carbon in mycorrhizal fungi in mixed forests

“…The difference between saprophytic and mycorrhizal fungi was found at both sites and is large enough to be developed as a tool to separate the two groups of fungi. For example, Chalciporus piperatus has been suspected to be mycorrhizal, but this has not been confirmed in experiments in which mycorrhizal syntheses have been attempted (20,21). Its high 13 C abundance at both sites (Table 1) would place this fungal species amongst the saprophytes.…”

Characterization and seasonal ecology of ectomycorrhizae associated with Sitka alder and lodgepole pine from naturally regeneraing young and mature spruce forests in the sub-boreal spruce zone of British Columbia

“…Most ectomycorrhizal fungi have a broad host range in that they are able to form mycorrhizae with many species of plant hosts and most ectomycorrhizal host plants are broadly receptive and recognize many species of mycobionts (Molina et al 1992). Paxillus involutus (Godbout and Fortin 1983). In contrast, a fungal species may form ectomycorrhizae with only one genus of plant as observed with Alpova diplophloeus on alder species (genus-specific or narrow host range) and can be considered to exhibit high specificity.…”

“…Characterization and identification of ectomycorrhizae associated with Alnus have traditionally been done through pure culture synthesis (Ekblad and Huss-Danell 1995;Arnebrant et al 1993;Godbout and Fortin 1983;Molina 1981Molina , 1979. Other studies have characterized and attempted to identify field-sampled ectomycorrhizal tips on alder (Pritsch et al 1997a(Pritsch et al , 1997bHelm et al 1996;Airaudi et al 1993;Miller et al , 1992Brunner et al 1990;Froidevaux 1973;Mejstrik and Benecke 1969).…”

“…In a follow up study, only 3 of 9 pure cultures formed ectomycorrhizae on A. glutinosa, A. incana , A. rhombifolia , and A. sinuata (Molina 1981 ). Similarly, Godbout and Fortin (1983) described 11 morphotypes from field-sampled A. rubra from in Oregon, and, in a follow-up study, determined that only 5 morphotypes were specific to A. rubra seedlings using a soil bioassay (Miller et al 1992). Airaudi et al (1993) examined field-sampled A. viridis in Italy and described 6 distinct morphotypes.…”

Les mycorhizes des plantes actinorhiziennes

“…A notre connaissance, jusqu' a main tenant, seuls Godbout et Fortin (1983 ), en etudiant 1' infection simultanee de l'aulne par Frankia et le champignon EM Alpova diplophloeus, ont apporte des indications precises sur le comportement de ces microorganismes soumis a 1' effet des activites specifiques de l'un et de l'autre.…”