EXPERIMENTAL CULTIVATION OF LICHENS AND LICHEN SYMBIONTS

Culture experiments with lichens and lichen symbionts are helpful for giving answers to many open questions in different fields of modern li chenology. Cultures are especially required for investigations where t he analysis of naturally grown thalli is inconclusive and more standar dized research material is needed. In the first part a short review of the artificial resynthesis of the cyanobacterial Peltigera praetextat a along with new results obtained by the culture of isidia are present ed. Another series of experiments report a successful resynthesis of t he photosymbiodeme Peltigera leucophlebia. Details of the thallus morp hogenesis and the formation of cephalodia in culture are shown. The re lated Peltigera aphthosa was cultured from small thallus fragments. In this case, the alpine P. aphthosa forms solely the cephalodiate thall us. A cyanobacterial morphotype as known from other culture experiment s and the related P. britannica is missing in culture. Further culture experiments are conducted with alpine species of the genus Cladonia ( e.g., Cl. fimbriata, Cl. furcata). Results show a quick redifferentiat ion and regeneration of squamules and podetia both by soredia and frag ments. The high capacity of thallus regeneration as shown for CI. furc ata seems to be absent in representatives of the Cladina group (e.g., Cl. portentosa, Cl, rangiferina).