EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
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SESSION 3: PATHOGENESIS – EPIDEMIOLOGY AND POPULATION<br />
GENETICS<br />
P52 - Aggressiveness and deoxinivalenol production<br />
<strong>of</strong> Fusarium graminearum isolates from different<br />
inoculum sources<br />
C. A. Mourelos 1 , I. Malbrán 1 , P. A. Balatti 1 , Q. Migheli 2 , G. A. Lori 1<br />
1 Centro de Investigaciones de Fitopatología, Facultad de Ciencias Agrarias y Forestales, Universidad<br />
Nacional de La Plata, 60 y 119, CC 31, (1900) La Plata, Buenos Aires, Argentina; 2 Dipartimento di<br />
Agraria - Plant Pathology and Entomology Unit, Università degli Studi di Sassari, Via E. De Nicola 9, I<br />
- 07100 Sassari, Italy.<br />
E-mail: mouceci@yahoo.com.ar<br />
Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe, is one<br />
<strong>of</strong> the most important fungal diseases affecting wheat. In addition to the severe<br />
yield and quality losses the disease causes, trichothecene contamination <strong>of</strong><br />
infected grains poses a serious threat to human and animal health. In Argentina<br />
more than three quarters <strong>of</strong> the total arable land is cultivated under no-tillage.<br />
Large quantities <strong>of</strong> crop residues remain on the soil surface, representing the<br />
principal reservoir <strong>of</strong> F. graminearum. Furthermore, in the southern hemisphere<br />
the presence <strong>of</strong> weeds in the field throughout the entire year has proven to be <strong>of</strong><br />
epidemiological importance as an inoculum source for FHB development. The aim<br />
<strong>of</strong> this work was to analyze aggressiveness towards wheat <strong>of</strong> F. graminearum<br />
isolates from different sources. Thirty-three isolates obtained from crop residues<br />
and symptomless inflorescences <strong>of</strong> gramineous (GW) and non-gramineous<br />
weeds (N-GW) were identified as F. graminearum based on their morphological<br />
and cultural characteristics, and confirmed by species-specific PCR.<br />
Aggressiveness <strong>of</strong> the isolates and FHB effect on thousand kernel weight (TKW)<br />
were tested by point inoculation (PI) <strong>of</strong> field grown wheat spikes. Inoculated<br />
spikes were hand threshed, grains were ground and DON was quantified by<br />
means <strong>of</strong> the RIDASCREEN® FAST DON ELISA kit (R-Biopharm). All isolates<br />
induced FHB symptoms on the spikes and accumulated DON in the grains. The<br />
isolates obtained from GW differed significantly in aggressiveness from those<br />
from N-GW (F=4.78, p