ARTIFICIAL RESYNTHESIS OF THALLI OF THE CYANOBACTERIAL LICHEN PELTIGERA-PRAETEXTATA UNDER LABORATORY CONDITIONS

The resynthesis of foliose thalli of the cyanobacterial lichen Peltigera praetextata was achieved on a soil substratum under laboratory conditions. On agar plates mycelia formation by this lichen fungus only occurred when a sufficient number of photobiont cells was present. Resynthesis on agar was restricted to the formation of loose algal-fungal associations, which showed no lichen-like structures. Early resynthesis stages were formed on soil only after a very long lag phase of 2–3 months. First soredia like stages (resynthesis products of fungal hyphae and cyanobacteria) appeared, later tissue clumps and thallus primordia differentiated. Well-developed lichen thalli with rhizines that resembled young thalli from the natural environment were formed after an incubation time of 2–3 years. © 1991, British Lichen Society. All rights reserved.