Fusarium Head Blight (FHB) is an important disease of wheat causing yield losses and grain contamination by several mycotoxins including trichothecenes (DON, NIV, T2, HT2, DAS) and “emerging” mycotoxins such as beauvericin (BEA) and enniatins (ENs). In the present work, we identified and characterized mycotoxin producing Fusarium species isolated from 162 durum and soft wheat samples cultivated in an area of central Italy in 2009 and 2010. Furthermore, the presence of mycotoxins in the grain was determined by LC-MS/MS and strains of F. graminearum s. str. (FG), F. culmorum (FC), F. avenaceum (FA), F. poae (FP), F. equiseti and F. sporotrichioides were tested in vitro for their ability to biosynthesize trichothecenes, BEA and ENs. In general, FG was the most frequently isolated species. In 2009, the occurrence of FA and FP was higher than in 2010. Among FG strains, the 15-ADON chemotype was the most frequent, followed by NIV and 3-ADON chemotypes, while all FC isolates belonged to the 3-ADON chemotype. All FP strains were NIV chemotypes. In vitro trichothecene production confirmed molecular characterization. All FA strains showed the ability to biosynthesize ENs in vitro but not BEA. All FP strains resulted to be NIV and BEA producers and some of them co-biosynthesized ENs. Regarding grain contamination, NIV was always detected at appreciable levels while T2+HT2 toxins were mostly found in durum wheat samples in 2009 with 6% of samples exceeding maximum levels (ML) recommended by the EU. A remarkable presence of ENs and co-contamination by BEA and ENs were also found. DON levels were always below ML. In general, a high presence of “secondary” FHB causal agents and their mycotoxins, which have not been yet legally regulated in the EU, were detected in the grain. Climatic conditions (rainfalls, temperatures) proved to be the predominant factors influencing mycotoxigenic species composition and mycotoxin contaminations. NIV contamination was found to occur disregarding climatic conditions, suggesting that it may often represent an underestimated risk.
The complexity of fusarium head blight disease may lead to constant wheat mycotoxin contaminations: a key study in Italy
COVARELLI, Lorenzo;BECCARI, GIOVANNI;
2014
Abstract
Fusarium Head Blight (FHB) is an important disease of wheat causing yield losses and grain contamination by several mycotoxins including trichothecenes (DON, NIV, T2, HT2, DAS) and “emerging” mycotoxins such as beauvericin (BEA) and enniatins (ENs). In the present work, we identified and characterized mycotoxin producing Fusarium species isolated from 162 durum and soft wheat samples cultivated in an area of central Italy in 2009 and 2010. Furthermore, the presence of mycotoxins in the grain was determined by LC-MS/MS and strains of F. graminearum s. str. (FG), F. culmorum (FC), F. avenaceum (FA), F. poae (FP), F. equiseti and F. sporotrichioides were tested in vitro for their ability to biosynthesize trichothecenes, BEA and ENs. In general, FG was the most frequently isolated species. In 2009, the occurrence of FA and FP was higher than in 2010. Among FG strains, the 15-ADON chemotype was the most frequent, followed by NIV and 3-ADON chemotypes, while all FC isolates belonged to the 3-ADON chemotype. All FP strains were NIV chemotypes. In vitro trichothecene production confirmed molecular characterization. All FA strains showed the ability to biosynthesize ENs in vitro but not BEA. All FP strains resulted to be NIV and BEA producers and some of them co-biosynthesized ENs. Regarding grain contamination, NIV was always detected at appreciable levels while T2+HT2 toxins were mostly found in durum wheat samples in 2009 with 6% of samples exceeding maximum levels (ML) recommended by the EU. A remarkable presence of ENs and co-contamination by BEA and ENs were also found. DON levels were always below ML. In general, a high presence of “secondary” FHB causal agents and their mycotoxins, which have not been yet legally regulated in the EU, were detected in the grain. Climatic conditions (rainfalls, temperatures) proved to be the predominant factors influencing mycotoxigenic species composition and mycotoxin contaminations. NIV contamination was found to occur disregarding climatic conditions, suggesting that it may often represent an underestimated risk.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
