Characterization of Nivalenol-Producing Fusarium asiaticum That Causes Cereal Head Blight in Korea

of the species complex causes head blight in small-grain cereals. The nivalenol (NIV) chemotypes of is more common than the deoxynivalenol (DON) chemotypes of or in Korea. To understand the prevalence of NIV in Korean cereals, we characterized the biological traits of 80 cereal isolates of producing NIV or 3-acetyl-deoxynivalenol (3-ADON), and 54 with 3-ADON or 15-acetyl-deoxynivalenol (15-ADON). There was no significant difference in mycelial growth between the chemotypes, but isolates grew approximately 30% faster than isolates on potato dextrose agar. Sexual and asexual reproduction capacities differed markedly between the two species. Both chemotypes of (3-ADON and 15-ADON) produced significantly higher numbers of perithecia and conidia than NIV. The highest level of mycotoxins (sum of trichothecenes and zearalenone) was produced by 3-ADON on rice medium, followed by 15-ADON, 3-ADON, and NIV. Zearalenone levels were correlated with DON levels in some chemotypes, but not with NIV levels. Disease assessment on barley, maize, rice, and wheat revealed that both and isolates were virulent toward all crops tested. However, there is a tendency that virulence levels of NIV isolates on rice were higher than those of isolates. Taken together, the phenotypic traits found among the Korean NIV isolates suggest an association with their host adaptation to certain environments in Korea.