Experiments with Different Methods of Isolating Physiological Mutations of Filamentous Fungi

Abstract

DURING recent years, I have tried various methods of isolating considerable numbers of X-ray induced physiological mutants in fungi, Ophiostoma multiannulatum being the chief organism experimented on¹. Of some six hundred mutants produced in this fungus, at present 463 are at least preliminarily classified, and thus the material in this case seems to be big enough to permit some general conclusions to be drawn as to the methods employed. 218 of these mutants have been isolated by the aid of some concentration method, the other 245 by the so called total isolation method. Some of the former were obtained from irradiated ascospores ; but most of them, as well as all the latter, were produced by irradiating conidia of the (+)-strain No. 11.