Toxigenic Fusarium species from rice seeds in Northern Italy

Northern Italy is the most important area (219.987 ha) for rice production in Europe. Several diseases caused by fungi affect this crop. Among these, species belonging to the genus Fusarium are the agents of many different plant and seed diseases, such as “bakanae” caused by Fusarium fujikuroi, “Fusarium sheath rot” by Fusarium proliferatum, “scab” by F. graminearum, and “grain discoloration”. There is considerable interest on the biodiversity of Fusaria, since they are worldwide pathogens of important cereal crops, including rice, so that the taxonomy of the species most frequently present on rice has recently been revised. These fungi produce a broad range of toxic compounds that affect human and animal health. Some of these toxins, such as deoxynivalenol and fumonisins, have been shown to possess phytotoxic activity and cause disease symptoms on the plants during the infection process. Seventy-three strains of Fusarium were isolated from seeds belonging to different Italian rice varieties. Samples were analysed with and without glumes. The identification of the strains was confirmed also by sequencing variable regions of their DNA, such as calmodulin, b-tubulin, and elongation factor. The strains were tested for in vitro deoxynivalenol, fumonisin, beauvericin and fusaproliferin production to assess their toxigenic potentiality. Most of strains were toxin producers, showing different toxin profiles according to their taxonomic allocation. Data on toxin production show that the contamination by Fusarium species of rice represents a risk also for human health.