Comparison of Fusarium culmorum chemotypes regarding to pathogenicity and zearelanone production at wheat

This study was conducted at the Dardanos Agricultural Research Station of Çanakkale Onsekiz Mart University in 2010-2011 wheat growing season. Fusarium head blight (FHB), caused by Fusarium culmorum, results in yield and quality reductions and mycotoxin accumulation. The aggresiveness among the F. culmorum chemotypes and reduction on yield was evaluated. Two wheat varieties (Golia and Ceyhan) and 16 isolates of the fungus were employed in the research. In addition, the mycotoxin, zearalenone (ZEA), contents in the infected kernels were also compared. The wheat heads was inoculated by a syringe during anthesis. Head blight severity was assesed 3 times and the data was used to calculate the area under disease progress curve (AUDPC). Significant variation in aggressiveness of isolates of F. culmorum was observed in both wheat varieties tested. The isolates of F. culmorum reduced significantly thousand kernel weights (TKW) at different levels in both varieties. No interaction was found between ZEA accumulation and isolates or wheat varieties. There was a positive correlation between head weight and TKW, but negative correlation between AUDPC and head weight or TKW. No correlation was found between ZEA and any other parameters assessed. We concluded that the isolates of F. culmorum differed in aggressiveness and reduced yield at different levels; ZEA accumulation was, however, not correlated with the disease severity.Keywords: Fusarium culmorum, Wheat, AUDPC, Head Weight, Thousand Kernel Weight, ZEA