Identification of Fusarium spp. and Penicillium verrucosum in the wheat grain chain.

Mycotoxins are secondary metabolites produced by several species of fungi during colonization and growth on plants. The occurrence of mycotoxins in commodities represents a major threat to humans and animals. Their formation in the infected crops and persistence in food and feed is associated with different toxicities including mutagenicity and estrogenic, gastrointestinal, urogenital, vascular, kidney and nervous disorders as well as the induction of cancer. Some mycotoxins are also immuno-compromising, and can thus reduce resistance to infectious agents (Desjardins, 2006). Moreover, significant economic losses are associated with the impact of mycotoxins on human health, animal productivity, and both domestic and international trade. It is estimated that 25% of the world food production, including many basic foods, are affected by mycotoxins producing fungi, while cereals appear to be contaminated to even higher levels (CAST, 2003). In particular, wheat is a crop that can be commonly contaminated by three of the most important mycotoxin-producing fungi: Aspergillus ochraceus, Penicillium verrucosum and Fusarium graminearum (Marasas et al., 2008). Therefore, three of the most important mycotoxins occurring in agricultural products, ochratoxin (produced on wheat mainly by A. ochraceus and P. verrucosum) and deoxynivalenol (DON) and zearalenone (ZEA), both produced on wheat mainly by F. graminearum, can be common contaminants of wheat (Miller et al., 1995). The detection and control of each toxigenic fungal species in planta is key to reduce fungal contamination and in turn prevent mycotoxins from entering the human food and animal feed.