VIEW ARTICLE

Postharvest Pathology and Mycotoxins

Distribution of Deoxynivalenol in Fusarium graminearum-Infected Maize Ears. L. M. Reid, Plant Research Centre, Central Experimental Farm, Agriculture and Agri-Food Canada, Ottawa, Ontario K1A 0C6; D. E. Mather(2), and R. I. Hamilton(3). (2)McGill University, Macdonald Campus, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, Québec, Canada H9X 3V9; (3)Plant Research Centre, Central Experimental Farm, Agriculture and Agri-Food Canada, Ottawa, Ontario K1A 0C6. Phytopathology 86:110-114. Accepted for publication 18 October 1995. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/Phyto-86-110.

The distribution of the mycotoxin deoxynivalenol in maize ears infected with Fusarium graminearum was determined. In 1990 and 1991, individual ears of five maize inbreds (CO272, F7, F2, A641, and CO266) and one hybrid (CO272 × CO266) were inoculated at approximately 6 days after silk emergence by the injection of a macroconidial suspension into the silk channel. Ears were harvested in mid-October and disease severity was visually evaluated using a rating scale of 1 to 7, in which 1 = no infection and 7 = > 75% of the kernels exhibiting symptoms of infection. Deoxynivalenol concentrations were determined in three ear tissue fractions: symptomless kernels, symptomatic kernels, and the cob. Disease severity ratings and deoxynivalenol concentrations were higher in 1990 than in 1991. In both years and for almost all genotypes, the highest concentration of deoxynivalenol was in the cob, followed by the symptomatic kernels and the symptomless kernels. Disease severity ratings of the ears at harvest were highly correlated to deoxynivalenol concentrations of kernels and whole ears.