17 F. Mert-Türk1 R. Gencer F. Kahriman Journal of Animal and Plant Sciences JAPS 20142014/12/01 24 6 1858-1862 1018-7081 NA <p>Fusarium head blight (FHB), caused mainly by&nbsp;<em>Fusarium graminearum</em>, is a devastating disease of wheat and other small grain cereals. FHB lowers grain yield and quality, and contaminates grain with mycotoxins, predominantly trichotecenes i.e nivalenol (NIV), deoxynivalenol (DON). A survey conducted at three Provinces in Turkey for FHB and 17 isolates were identified as&nbsp;<em>F. graminearum</em>&nbsp;using morphological and molecular markers. A PCR assay was carried out to identify the chemotypes of the isolates. Using&nbsp;<em>Tri13</em>&nbsp;gene cluster, all 17 isolates that were identified to 15-AcDON type of DON chemotype. None of the isolates displayed 3-ADON or NIV chemotypes. In order to assess variation in aggressiveness among isolates, all isolates were inoculated to a susceptible wheat spikes at field conditions and disease severity and a thousand kernel weight were measured. Aggressiveness (measured as FHB severity or TKW) differed significantly among 17&nbsp;<em>F. graminearum&nbsp;</em>isolates inoculated onto wheat spikes of FHB susceptible cultivar G&ouml;nen (<em>P</em>=0,05). Means of FHB severity ranged from 39.75 to 86.33%, averaging 63.29% in total. Reduction in TKW was also reduced significantly by different isolates. Differences in aggressiveness among isolates may due to genetic recombination, mutation or selection in the surveyed area.</p> Fusarium graminearum, mycotoxins, chemotypes, DON, NIV, pathogenicity, aggressiveness Pakistan Agricultural Scientists Forum https://thejaps.org.pk/AbstractView.aspx?mid=2014-JAPS-265