New Method of Isolating the Tetrads of Agarics

Abstract

HITHERTO the usual technique for isolating tetrads from Agarics has been to detach a piece of gill tissue from a mature sporophore and then, with the aid of a micromanipulator, to pick off whole tetrads directly from the fresh gill. There are three main difficulties inherent in this method: (a) because of the high numerical density of tetrads on the gill, it is very difficult to be sure that no extraneous spores have been picked up by the micro-manipulator needle until the spores are parked on the germination medium; (b) it is impossible to distinguish unripe from ripe tetrads, and since the former are removed from their basidia with great difficulty, many abortive attempts to pick up tetrads are frequently made before a tetrad is successfully removed; (c) in the case of Coprinus, autolysis of the gill can greatly limit the time available for isolation.