POPULATION-STRUCTURE OF TYPHULA-ISHIKARIENSIS IN MEADOWS AND PASTURESIN NORWAY

Isolates of Typhula ishikariensis, a snow mould fungus, from Norway we re divided into three groups, which, although differing in culture mor phology and in mating reactions with testers of T. ishikariensis bioty pes A and B from Japan, were, at least partially, interfertile. Popula tion structures of this fungus at 23 sites in meadows and pastures wer e then determined, based on vegetative compatability group. Except for two sites dominated by a single large vegetative compatibility group, populations were generally diverse, regardless of the cropping histor y of the site.