Sporulation mutants inCochliobolus carbonum

摘要

Three types of mutants were induced in cultures ofCochliobolus carbonumby ultraviolet irradiation. The mutant C1abcformed abnormally shaped conidia which proliferated in chains rather than being arranged in a spiral on the conidiophore as in wild-type isolates; a second mutant, C2pcg, produced conidia which germinated precociously while still attached to the conidiophore and which formed secondary conidia at the ends of short germ tubes; and the third, C1nc1, formed no conidia. A fourth mutant, C1nc2, which also failed to form conidia was isolated from a culture grown on a medium containing acriflavin. A 1: 1 segregation ratio was obtained in crosses of C1abctimes; wild type, but in crossesC2pcgtimes; wild type and C1nc1times; wild type nearly all of the progeny were wild type. The mutants C2pcgand C1nc1failed to form perithecia but could serve as male parents; C1nc2was completely infertile. Preliminary attempts to determine whether thepcgandncmutants were controlled cytoplasmically were inconclusive.