Biochemical Mutants in the Smut Fungus Ustilago Maydis

HE usefulness of growth-factor mutants for genetic studies was demon-T strated by BEADLE and TATUM in 1941, using the mold Neurospora. Although a number of other microorganisms have since been employed in studies of a similar nature, there has until recently been no instance of the use of biochemical mutants in sexual fungi other than Ascomycetes. This paper is concerned with the production, characterization and inheritance of requirements for essential metabolites in a parasitic basidiomycete, the smut-fungus of corn, Uslilago maydis (DC.) Cda. (Ustilago zeae, cf. STEVENSON and JOHN-SON 1944).