ASSESSMENT OF SPECIES DISTRIBUTIONS IN PLEUROTUS BASED ON TRAPPING OFAIRBORNE BASIDIOSPORES

A species-specific spore trapping method was employed to detect differ ent species of the oyster mushroom genus Pleurotus from different geog raphic regions. Monokaryotic tester strains representing five interste rility groups in the P. ostreatus complex were used as spore trap bait s. Colonies of each strain were exposed to the outside environment fro m 24 to 48 hours. Afterward, explants taken from the plates were trans ferred to fresh media and observed for evidence of dikaryotization. Se ts of petri dishes containing all five species were distributed by mai l to mycologists at diverse locations in the Northern Hemisphere, wher e they were placed out for sampling and later returned by mail for sco ring. In spite of a relatively high level of contamination, dikaryotiz ation was observed for all five species. The results suggest that spor e trapping in this manner can be an effective method for sampling gene tic diversity over broad geographic areas.