Ascocarp production byNannizziaandArthrodermaon keratinous and non-keratinous media

Abstract
Ascocarp production by the 22 known species of Nannizzia and Arthroderma was compared on 2 keratinous and 3 non-keratinous agar media. Other factors influencing ascocarp production, such as the medium used for maintenance of the tester strains, the age of the cultures, and the technique used in crossing the strains, were also studied. Ascocarps were regularly produced by all but 1 of the species on the keratinous media. Six of 8 Nannizzia species and 12 of the 14 Arthroderma species also formed gymnothecia on Oatmeal salts agar and on Pablum cereal agar. Diluted Sabouraud dextrose agar supported ascocarp production in only 3 species of each genus. Using conidial suspensions for inoculum rather than small cubes cut out of colonies was found superior for ascocarp production. Inocula originating from young (10-day) colonies resulted in a larger number of gymnothecia than inocula from old (20-day) colonies. Media containing high content of sugars and peptones were found unsuitable for maintenance of tester strains. When kept for more than 6 months, they promoted sterile sectors and strain degeneration.