VIEW ARTICLE

Genetics

Influence of Naturally Occurring Marker Genes on the Ability of Cochliobolus heterostrophus to Induce Field Epidemics of Southern Corn Leaf Blight. W. E. Fry, Department of Plant Pathology, Cornell University, Ithaca, NY 14853; O. C. Yoder(2), and A. E. Apple(3). (2)(3)Department of Plant Pathology, Cornell University, Ithaca, NY 14853. Phytopathology 74:175-178. Accepted for publication 30 July 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-175.

Three loci in the plant pathogenic fungus Cochliobolus heterostrophus were evaluated in a common genetic background under field conditions: Alb1, which controls pigment production; Cyh1, which conditions relative sensitivity to cycloheximide; and MAT, which determines mating type. Albino isolates with no pigment (alb1) caused no measurable epidemic; cyh1^R (resistant to cycloheximide) reduced the rate of epidemic development compared with CYH1^S (sensitive to cycloheximide), but only in a MATA background (there was no difference when alleles at Cyh1 were compared in a MATa background); alleles at MAT had no consistent effect on epidemic development. The differences between alleles observed in the field were not readily apparent in growth chamber experiments.