VIEW ARTICLE

Ecology and Epidemiology

Components of Fitness Attributes in Cochliobolus carbonum Race 3. A. H. Hamid, Graduate student, Department of Plant Pathology, Regional Pasture Research Laboratory, USDA, ARS, The Pennsylvania State University, University Park 16802, Present address: Malaysian Agricultural Research and Development Institute (MARDI) Serdang, Selangor, Malaysia; J. E. Ayers(2), R. D. Schein(3), and R. R. Hill, Jr.(4). (2)(3)Professors, Department of Plant Pathology, Regional Pasture Research Laboratory, USDA, ARS, The Pennsylvania State University, University Park 16802; and (4)Research agronomist, Regional Pasture Research Laboratory, USDA, ARS, The Pennsylvania State University, University Park 16802. Phytopathology 72:1166-1169. Accepted for publication 21 January 1982. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1982.. DOI: 10.1094/Phyto-72-1166.

Three components of parasitic fitness of Cochliobolus carbonum (=Helminthosporium carbonum) race 3 were investigated in growth chamber experiments on 3-wk-old susceptible corn (Zea mays) inbred lines. Disease efficiency (DE), lesion length (LL), and sporulation capacity (SC) were studied. There were significant differences in DE, LL, and SC among isolates and among host × isolate interactions. Heritability estimates for DE, LL, and SC were 0.77, 0.87, and 0.60, respectively, indicating that it should be possible for natural selection to operate in favor of increased parasitic fitness of the pathogen.