SPATIAL DEVELOPMENT OF POPULATIONS OF CORIOLUS VERSICOLOR

were similar to those found in natural populations of the fungus, with individual dikaryons present in discrete regions delimited by zones of mutual antagonism. Different dikaryons had similar growth rates and occupied approximately equal areas or volumes when inoculated simultaneously on to agar or into wood respectively. Simultaneous and sequential inoculation of sexually compatible monokaryons on to agar demonstrated that growth rate of the monokaryons and patterns of dikaryotization and nucleus migration between them are likely to be crucial determinants of the spatial distribution of dikaryons in a population. Monokaryons inoculated into logs in the field quickly became dikaryotized, and the resulting dikaryons contained diverse mating-type factors indicating the presence of a heterogeneous spore rain.