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SESSION 3: PATHOGENESIS – EPIDEMIOLOGY AND POPULATION
GENETICS
P65 - Molecular and chemical analysis of
trichothecene diversity of Gibberella zeae populations
from corn, wheat and potatoes in eastern Canada
R. R. Burlakoti 1 *, L. Tamburic-Illincic 2 , V. Limay-Rios 2 , R. D. Peters 3 , and P.
Burlakoti 2
1 Weather INnovations Incorporated, Chatham, Ontario; 2 University of Guelph, Ridgetown Campus,
Ridgetown, Ontario; 3 Agriculture and Agri-Food Canada, Charlottetown, Prince Edward Island
E-mail: rburlakoti@weatherinnovations.com
Gibberella zeae, a principal pathogen of Fusarium head blight of wheat and ear
rot of corn in Canada, causes significant yield and quality losses as well as
contaminates grains with trichothecene mycotoxins. The fungus is also a potato
pathogen and is routinely recovered from potato tubers showing symptoms of
Fusarium dry rot in Canada. Corn, wheat and potatoes are economically
important crops in eastern Canada and these crops are commonly rotated or
grown in nearby fields. Therefore, comparative analysis of the trichothecene
diversity and population structure of G. zeae isolates from these crops will be
useful to develop strategies to manage the diseases in these crops. In addition,
multiyear comparisons of fungal populations across diverse regions will identify
the impact of weather patterns and other agronomic factors on pathogen
populations and disease potential. Gibberella zeae isolates were recovered from
corn and wheat grain samples collected from 25 diverse locations in Ontario
during 2010 and 2011. Fungal isolates from potato were recovered from samples
collected in Quebec, New Brunswick, and Prince Edward Island. Approximately
250 single spore strains of G. zeae (187 from corn, 49 from wheat, and 14 from
potatoes) were characterized and trichothecene genotypes were identified using
TRI3- and TRI-12 based molecular markers. Molecular analysis revealed that the
majority of G. zeae strains from corn and wheat were 15-Acetyl-DON (15ADON)
types (97% and 98%, respectively). Interestingly, all the G. zeae strains from
potatoes were 3-Acetyl-DON (3ADON) types. The ability of representative isolates
to produce 3ADON and 15ADON was verified in rice culture with TLC and
quantified using an ESI-LC-MS/MS system. Characterization and trichothecene
profiling of G. zeae isolates collected in 2012 is in progress. This study will
provide base-line data on 3ADON and 15ADON profiles of G. zeae isolates from
wheat, corn and potatoes in eastern Canada.
Keywords: Gibberella, Trichothecene, population structure
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