Occurrence ofFusarium mycotoxins and toxigenicFusarium species in freshly harvested rice in Jiangsu, China

In 2017, 236 rice samples were collected from 42 counties in Jiangsu province, China, and analysed forFusarium mycotoxins. Mycotoxin analyses showed that deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), nivalenol (NIV), fusarenone X (FUS-X), zearalenone (ZEA), fumonisins (including FB1, FB2, and FB3), and beauvericin (BEA) were present in unhusked rice samples. Regional differences in mycotoxin contamination of unhusked rice were attributed to differences in precipitation during rice anthesis and agricultural practices among the three study regions. Importantly, the mean concentrations of DON, NIV, ZEA, and fumonisins in white rice were significantly lower than those in unhusked rice, and the relative proportion of the toxins in rice by-products exceeded 84%.Fusarium isolates were then obtained from the unhusked rice samples;Fusarium asiaticum was the most common, followed byFusarium fujikuroi, Fusarium proliferatum, Fusarium verticillioides, andFusarium commune. Genotype and chemical analyses of mycotoxins showed that mostF. asiaticum isolates (71%) were 3-ADON chemotypes; the remainder were NIV producers. All of theF. proliferatum andF. verticillioides isolates, and most of theF. fujikuroi isolates produce fumonisins, and most of the three species coproduced BEA. The present study is the first to evaluateFusarium mycotoxins and toxigenicFusarium species from rice freshly harvested in Jiangsu province, China. The results of this study improve our understanding the population dynamics ofFusarium species in rice and the development of effective control measures.