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The identity of black alder (Alnus glutinosa (L.) Gaertn.) ectomycorrhizas was investigated using PCR/RFLP analysis of the ITS region from 16 morphotypes sampled at a 60-yr-old black alder stand. A comparison was made with restriction patterns from sporocarps of 28 mycobionts, of which 16 originated from the same stand, the remaining 12 came from two geographically distant alder stands. Eight of the mycorrhizal types could thus be identified, whereas eight mycorrhizal types remained unidentified. The identified mycorrhizas belonged to the genera Russula, Lactarius, Naucoria and Cortinarius. Four of the identified ectomycorrhizal types had identical PCR/RFLP profiles to corresponding fruit bodies from all investigated stands with no detectable intraspecific variation between sporocarps from the different locations was detected in Paxillus rubicundulus, mycorrhizas of which were not found. The diversity of fruiting alder mycobionts at the main experimental plot only partly matched the diversity observed from mycorrhizas when comparing their PCR/RFLP analyses and ecological aspects. [ABSTRACT FROM AUTHOR]

Morphologically similar ectomycorrhizas between Scots pine (Pinus sylvestris L.) seedlings and different geographic isolates of Suillus variegatus (Fr.) O. Kuntze and Suillus bovinus (Fr.) O. Kuntze were synthesized under semi-aseptic conditions in a sand and peat growth mixture containing ureaformaldehyde as the organic nitrogen source. Fourteen weeks after inoculation significant increases in shoot height were recorded in most of the infected seedlings and in two inoculated treatments where no mycorrhizal infection was detected. Based on the assumption that 50% of the dry mass of these ectomycorrhizas was of fungal origin, the soluble protein content of the synthesized ectomycorrhizas was found to be between 10- and 15-fold greater than in equivalent amounts of the non-symbiotic tissues (short roots and axenically grown mycelium of S. variegatus and S. bovinus). Extracts from individual ectomycorrhizas exhibited considerable esterase (EST) and peptidase (PEP) isozyme activities following PAGE and it was confirmed that diagnostic species-specific fungal isozymes, reproducibly detected in these extracts, were present in extracts of excised sheath tissue. Acid phosphatase (ACP isozyme activities were also detected in the ectomycorrhizas but were restricted to a single isozyme known to be common to both fungal species. In addition to the identification of taxonomically useful diagnostic fungal isozymes. the lack of detectable host PEP or ACP isozymes in these individual ectomycorrhizas, which also exhibited induced isolate-specific EST isozymes, provides further information on the biochemical relationships in the ectomycorrhizas. [ABSTRACT FROM AUTHOR]