A developmental variant of Agaricus bisporus

Abstract

Studies on sporophore initiation in the cultivated mushroom, Agaricus bisporus (Lange) Imbach are hampered by the difficulty of inducing strains to fruit in axenic culture. Two isolates from a single basidium have been found which readily produce fruit-body primordia in axenic culture on both complex and defined media. The chitin content, level of intracellular laccase, and response to carbon dioxide of these isolates indicated that the structures formed are directly comparable to the initial stages of normal sporophore development. The fruit-body initials from these two strains are produced at high frequency, synchronously and during active growth. This is in marked contrast to the behaviour of other mushroom strains in axenic culture.The origin of these isolates is described and their genetic basis discussed.