A great deal of patience is required to reveal intact connections between stipe base and ectomycorrhiza (Fig. 2D), but in some cases large
numbers of ectomycorrhiza can be detected, connected repeatedly with the stipe of the fruit body (Fig. 2C). In identification probes, those ectomycorrhiza which are directly attached to the stipe, or are enveloped by stipe tissue, must not be regarded as belonging to that fruit body because foreign ectomycorrhiza can be overgrown by the fungus.
Only ectomycorrhiza in which, to which or from which unequivocal hyphal or rhizomorph connections can be traced should be regarded as identified. In addition, the rhizomorphs and hyphae of both stipe base and ectomycorrhiza should be compared microscopically. Not all fungal relationships are amenable to this method of hyphal tracing. This procedure is very difficult in some genera, e.g. Lactarius, Russula,
Fig. 2. Samples and first steps of preparation. (A) Taking identification probes. (B) Tools for isolation of ectomycorrhiza. (C) Several ectomycorrhiza connected with two stipe bases. (D) First uncovered ectomycorrhiza near stipe base. Key: 1, fruit body; 2, cut stipe base; 3, ectomycorrhiza; 4, knife; 5, whetstone; 6, fine paint brushes; 7, fine needles; 8, thin pipette; 9, fine forceps; 10, small pair of scissors; 11, pin, marking the stipe base. Bar, 5 mm.
Hygrophorus and Inocybe. However, it works well with species of the genera Cortinarius, Dermocybe, Sarcodon, Tricholoma and Xerocomus. Sometimes several attempts are necessary, but there are some cases where success has never been achieved.
All ectomycorrhiza regarded as being of one species and one sample must be checked for homogeneity. In order to do this a few tips should be carefully compared both morphologically and anatomically using rhizomorph and mantle preparations.
If agar cultures can be obtained from isolates of fruit bodies and ectomycorrhiza, then further confirmation of the identification can be achieved by comparing these cultures. If cultures are only available from fruit bodies, then synthesis tests under at least semi-natural conditions (Read et al., 1985; Brand and Agerer, 1986) should result in the production of ectomycorrhiza of similar structure with respect to mantle and rhizomorph organization and hyphal features. Voucher specimens of each homogeneous sample should be stored (see Section VI.A).
Was this article helpful?