Experimental cultivation of lichens and lichen symbionts

Abstract

Culture experiments with lichens and lichen symbionts are helpful for giving answers to many open questions in different fields of modern lichenology. Cultures are especially required for investigations where the analysis of naturally grown thalli is inconclusive and more standardized research material is needed. In the first part a short review of the artificial resynthesis of the cyanobacterial Peltigera praetextata along with new results obtained by the culture of isidia are presented. Another series of experiments report a successful resynthesis of the photosymbiodeme Peltigera leucophlebia. Details of the thallus morphogenesis and the formation of cephalodia in culture are shown. The related Peltigera aphthosa was cultured from small thallus fragments. In this case, the alpine P. aphthosa forms solely the cephalodiate thallus. A cyanobacterial morphotype as known from other culture experiments 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 redifferentiation and regeneration of squamules and podetia both by soredia and fragments. The high capacity of thallus regeneration as shown for Cl. furcata seems to be absent in representatives of the Cladina group (e.g., Cl. portentosa, Cl. rangiferina). Key words: lichen culture, resynthesis, tissue culture, Peltigeraceae, cyanobacterial lichens, photosymbiodemes, Peltigera leucophlebia, Peltigera aphthosa, Cladoniaceae, Cl. fimbriata, Cl. furcata.