02985nam a2200253 a 450000100080000000500110000800800410001910000180006024501590007826001370023730000110037452021510038565000110253665000160254765300110256365300300257465300240260470000180262870000150264670000270266170000160268870000130270470000140271710598322019-06-07       2018    bl uuuu     u00u1 u    #d1 aGARMENDIA, G.  aSpecies composition, toxigenic potential and aggressiveness of Fusarium isolates causing Head Blight of barley in Uruguay.[Poster].h[electronic resource]  aIn: Proceedings of the Fusarium head blight Forum, December 2-4, 2018, Regency St. Louis at the Arch St. Louis, Missouri, USA.c2018  ap. 84.  aABSTRACT:Fusarium Head Blight (FHB) represents one of the major constraints for barley production in Uruguay and significantly decreases grain yield and quality. FHB is also a major food safety concern because causal agents contaminate grains with trichothecenes and other mycotoxins. DNA sequence-based analyses and in-vitro toxin assessments were used to characterize species and trichothecene chemotype composition of FHB pathogens on barley grains in Uruguay. Fusarium graminearum was the dominant species (89.7%), and three other members of the F. graminearum species complex (FGSC) were identified as FHB pathogens of barley in Uruguay for the first time. Other minor FHB species included F. poae,F. avenaceum, F. pseudograminearum and an unnamed species of the F. incarnatum-equiseti species complex (FIESC). Most isolates (89.7%) had the 15-acetyldeoxynivalenol (15-ADON) trichothecene type. Yet, results from this study expanded the known area of occurrence within Uruguay for the nivalenol (NIV) toxin type, which was observed among isolates from three species of the FGSC, F. pseudograminearum, and F. poae. Isolates with the 3-acetyldeoxynivalenol (3-ADON) or NX-2 toxin types were not observed, although a previously published multilocus genotyping assay was updated to identify NX-2 strains. Analyses of population structure and comparisons with FHB isolates from wheat in Uruguay indicated that F. graminearum constitutes a single genetic population with no evidence of population differentiation related to the sampled hosts. Inter and intraspecific differences were observed in aggressiveness toward four barley genotypes with different levels of resistance to FHB, and in general nivalenol producers were the least aggressive isolates. Sensitivity to metconazole was approximately 10 times higher than the one detected for tebuconazole. This is the first report regarding tebuconazole and metconazole sensitivity for Fusarium species causing FHB in barley in Uruguay and establishes an important starting point for monitoring temporal or spatial changes in FGSC sensitivity, which is critical to define FHB management practices.  aCEBADA  aMICOTOXINAS  aBARLEY  aFUSARIUM HEAD BLIGHT(FHB)  aTIZÓN DE LA CABEZA1 aPATTARINO. L.1 aNEGRIN, C.1 aMARTÍNEZ-SILVEIRA, A.1 aPEREYRA, S.1 aVERO, S.1 aWARD, T.J