VIEW ARTICLE

Ecology and Epidemiology

Distribution of Mycosphaerella ligulicola and Selection for Environmental Races. R. E. McCoy, University of Florida Agricultural Research Center, 3205 SW College Avenue, Fort Lauderdale 33314 USA; J. P. Blakeman, University of Aberdeen, Botany Department, Aberdeen AB9 2UD, Scotland, U.K. Phytopathology 66:1310-1312. Accepted for publication 26 April 1976. Copyright © 1976 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-66-1310.

Populations of Mycosphaerella ligulicola in the United States and in Great Britain, although morphologically identical, are distinctly different in reproductive response to long wave ultraviolet irradiation (UV). Most American isolates require UV for induction of pycnidia, whereas all British isolates tested produced pycnidia in total darkness. By following the historical distribution of M. ligulicola from its type locality into areas of differing cultural environment it is possible to account for the selection and proliferation of races of the fungus that differ markedly in response to environmental stimuli.