ONTOGENY OF SYNTHESIZED PICEA-ABIES (L) KARST - HEBELOMA-CRUSTULINIFORME (BULL EX ST-AMANS) QUEL ECTOMYCORRHIZAS

Ectomycorrhizas were synthesized between Picea abies (L.) Karst. and H ebeloma crustuliniforme (Bull. ex St Amans) Quel. in growth pouches co ntaining activated charcoal filter paper. Immediately emanating hyphae from inoculated plugs contacted root hairs and root surfaces, hyphal morphology was altered. They became short-celled with few clamp connec tions, highly branched, and lacked cell wall ornamentation. Then, hyph ae on root surfaces formed an inner synenchymatous mantle and loose hy phae formed an outer prosenchymatous mantle. Simultaneously, root cap cells became invaded by fungal hyphae and their remnants were incorpor ated into the inner mantle. Further root elongation took place but roo t hair production was suppressed. Thirdly, a Hartig net began to form in basal portions of developing ectomycorrhizas and the fungal mantle became denser and thicker. Fourthly, growth of the root was reduced an d the hyphae of the Hartig net penetrated between cortical cells movin g toward the apex. Fifthly, metacutis occasionally surrounded the meri stem. At this stage the formation of the ectomycorrhiza can be conside red to be complete and the rootlet itself is temporarily in a dormant state.