INTERACTIONS BETWEEN MATING AND SOMATIC INCOMPATIBILITY IN THE BASIDIOMYCETE STEREUM-HIRSUTUM

Experimental systems for studying the migration of nuclei into mating-type compatible homokaryons across a pre-existing or developing somatic incompatibility barrier are described. Using these systems with S. hirsutum Willd. ex Fr. showed that different donor nuclei migrated from implants at more or less equal rates through acceptor homokaryons. However, access of nuclei across a somatic incompatibility barrier was subject to delay, selectivity favoring those non-sib-related to the acceptor, as opposed to sib-related nuclei. The selective delay was greater across a pre-formed than a developing barrier, and in the latter case there was evidence of suppression of the somatic incompatibility reaction associated with passage of non-sib nuclei.