RT Journal Article SR Electronic(1) A1 Leach, J. A1 Lang, B. R. A1 Yoder, O. C.YR 1982 T1 Methods for Selection of Mutants and In Vitro Culture of Cochliobolus heterostrophus JF Microbiology, VO 128 IS 8 SP 1719 OP 1729 DO https://doi.org/10.1099/00221287-128-8-1719 PB Microbiology Society, SN 1465-2080, AB Auxotrophic, morphological and drug-resistant mutants of Cochliobolus heterostrophus (= Bipolaris maydis = Helminthosporium maydis = Drechslera maydis) were isolated after mutagenesis with ethyl methanesulphonate. Exposure of the fungus to other mutagens (N-methyl-N′-nitro-N-nitrosoguanidine, nitrous acid, and UV light) resulted in recovery of morphological but not auxotrophic mutants. Antibiotic enrichment or filtration enrichment in medium containing high levels of sorbose increased the proportion of auxotrophs in the surviving population. All sexually fertile mutants were found to have single gene lesions; those with the same phenotype were allelic in some cases but not in others. Defined minimal and complete media, designed to facilitate genetic and molecular biological manipulations, supported maximal growth rate at 30 °C and maximal conidiation of the fungus at 23 °C with a 16 h long-wave UV light photoperiod. Under all in vitro growth conditions tested, near-isogenic lines of two known races of the fungus were essentially identical. Sexual fertility was improved by a programme of breeding and selection, but not by physical or chemical changes in the medium used for crossing. The fungus can be stored conveniently on silica gel., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-128-8-1719