ABSTRACT
The environmental conditions necessary for the maintenance of intact lichens have been discussed by V. Ahmadjian. Cultures of lichens can be produced in the laboratory by resynthesis of the isolated symbionts. For short-term experiments, cultivation of mycobionts can be conveniently done on microscope slides. Examination of lichens in a dissecting microscope often provides valuable clues for the isolation of photobionts. Protocols for the purification of photobionts by differential centrifugation have been published by several workers. Photobiont cells with hyphal fragments attached to their walls are transferred with the micropipette through successive sterile water drops on the slide until visible impurities are removed. Micropipettes may be less suitable for photobionts without attached hyphae or for very small photobionts. Suitable growth media for cultivation of mycobionts may be problematic since mycobionts appear to be somewhat individualistic in their nutrient requirements. Photobionts may also be isolated as they grow from thallus fragments incubated in liquid or on agarized media.
