Characterization of carbendazim sensitivity and trichothecene chemotypes of Fusarium graminearum in Jiangsu Province of China

• MBC resistance frequency of Fusarium graminearum shows ascending tendency.
• Reveal the mycotoxin chemotypes variations among MBC-resistant and sensitive strains.
• MBC resistance increases the production ability of 3-AcDON chemotype trichothecene.

Fusarium head blight, one of the most damaging plant diseases in Jiangsu province of China, is a leading cause of economic loss and toxin accumulation in the crop, including nivalenol, deoxynivalenol and its acetylated derivatives. Disease control by carbendazim (MBC) has been applicated for many years, and the resistance frequency increased steadily. Furthermore, resistance may trigger toxin growth. Here, a total of 7261 isolates were collected throughout Jiangsu province from 2010 to 2012 to determine their sensitivity to MBC and trichothecene chemotypes. We studied the relevance between trichothecene chemotype and MBC-sensitivity, and found that the MBC-sensitive isolates occupied more NIV chemotype proportion up to date; 15-AcDON chemotype only existed in MBC-sensitive isolates; and most MBC-resistant isolates secreted 3-AcDON in chemotype. Besides, trichothecene production analyses indicated that MBC resistance increased 3-AcDON yield and percentage, especially site-directed mutants at codon 167 in the β2-tubulin gene.