Anatomy Anatomy of haustoria

anatomy haustoria {of foreign origin} frequency

This item considers haustoria from the view point of the ectomycorrhiza; the view point of a fungus forming the haustoria is concerned. The negative proof is very difficult, but most of the time ectomycorrhizae lack foreign haustoria. If it was possible to prove that haustoria found do not belong to the ectomycorrhiza former, they are regarded as being of foreign origin. This can be done by detection of different staining behaviour of haustoria and/or their subtending hyphae, by tracing hyphae from the haustoria to those which with certainty do not belong to the ectomycorrhiza former, or by the presence of basidiomycetous features within an ascomycetous ectomycorrhiza and vice versa. Different shapes of haustoria are known (A-D). Some ectomycorrhizae can be associated consistently with hyphae and haustoria of foreign fungi. 'Consistently' stands for the presence in several mycorrhizae; per mycorrhiza they can occur in different densities. 'Occasionally' means that the occurrence is restricted to some cells of a few mycorrhizae.

A	B	C
D

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