The Luxembourg database of trichothecene type B F. graminearum and F. culmorum producers.

Data specific to 486 strains belonging to Fusarium graminearum and Fusarium culmorum were manually collected from Luxembourg field monitoring campaigns between the year 2007 ad 2013. It is of interest to store such data in a web-enabled advanced database to help in epidemiological studies. Hence, we describe the design and development of a Fusarium database added to the Luxembourg Microbial Culture Collection (LuxMCC™) web interface at the Luxembourg Institute of Science and Technology (LIST). The database has three main features: (1) filter search, (2) detailed viewer of isolate information, and (3) excel export function of the dataset. Information on fungal strains includes genetic chemotypes, data on selected agronomic factors and crop management issues with geographic localization. The database constitutes a rich source of data for addressing epidemiological issues related to these two species. It will be regularly updated with improved features for advancement and utility.

Evidence for a reversible drought induced shift in the species composition of mycotoxin producing Fusarium head blight pathogens isolated from symptomatic wheat heads.

Fusarium species are fungal plant pathogens producing toxic secondary metabolites such as deoxynivalenol (DON), 15-acetyl-deoxynivalenol (15AcDON) and nivalenol (NIV). In Luxembourg, the Fusarium species composition isolated from symptomatic winter wheat heads was dominated by Fusarium graminearum sensu stricto strains (genetic 15AcDON chemotype) between the years 2009 and 2012, except for 2011, when Fusarium culmorum strains (genetic NIV chemotype) dominated the pathogen complex. Previous reports indicated that F. graminearum sensu stricto (genetic 15AcDON chemotype) was also most frequently isolated from randomly sampled winter wheat kernels including symptomatic as well as asymptomatic kernels in 2007 and 2008. The annual precipitation (average of 10 weather stations scattered across the country) decreased continuously from 924.31mm in 2007 over 917.15mm in 2008, to 843.38mm in 2009, 736.24mm in 2010, and 575.09mm in 2011. In 2012, the annual precipitation increased again to 854.70mm. Hardly any precipitation was recorded around the time of wheat anthesis in the years 2010 and 2011, whereas precipitation levels >50mm within the week preceding anthesis plus the week post anthesis were observed in the other years. The shift to genetic NIV chemotype F. culmorum strains in 2011 was accompanied by a very minor elevation of average NIV contents (2.9ngg(-1)) in the grain. Our data suggest that high NIV levels in Luxembourgish winter wheat are at present rather unlikely, because the indigenous F. culmorum strains with the genetic NIV chemotype seem to be outcompeted under humid in vivo conditions by F. graminearum DON producing strains on the one hand and seem to be inhibited - even though to a lower extent than DON producing strains - under dry in vivo conditions on the other hand.