GENETIC CONTROL OF CONIDIATION IN ASPERGILLUS RUGULOSUS

The potential for the production of abundant conidia was suggested when an essentially non-conidial isolate of Aspergillus rugulosus, obtained from dune sand, was grown at 25 C rather than at the usual 37 C. Ultraviolet-light-induced conidial strains were obtained from the original non-conidial isolate. Evidence is presented which suggests that the production of conidia is under the control of a single nuclear gene. The data, with a single exception, suggest that induced conidial mutations represent alterations at the same locus. Crosses with isolates from various localities indicate that the genes controlling conidiation in these strains may be linked to or independent of the genes studied in the original dune-sand isolate. No evidence has been obtained which would suggest involvement of a diffusible substance in the control of conidiation.