METHOD FOR INDUCING SPORULATION OF PURE CULTURES OF THE MYXOMYCETE PHYSARUM POLYCEPHALUM

Abstract

Daniel, John W. (University of Wisconsin, Madison) and Harold P. Rusch . Method for inducing sporulation of pure cultures of the myxomycete Physarum polycephalum . J. Bacteriol. 83: 234–240. 1962.—Techniques for inducing sporulation of pure cultures of Physarum polycephalum are described. Small plasmodia grown in agitated culture were harvested, allowed to fuse into large plasmodia (1.3 g wet weight each), and, after incubation in the dark on a salts medium, exposed to light for 2 hr. The ensuing formation of sporangia containing spores was complete after 12 to 16 hr. The obligatory conditions for sporulation are: (i) an optimal growth age occurring just prior to the maximal growth of the organism and at a time when nutrients in the medium are exhausted; (ii) 4 days of incubation on a medium containing only inorganic salts and niacin or tryptophan; and (iii) subsequent illumination with light of wavelengths between 350 and 500 mμ.