Biogeography ofFusarium graminearumspecies complex and chemotypes: a review

Abstract

Differences in the geographic distribution of distinct trichothecene mycotoxins in wheat and barley were first recorded two decades ago. The different toxicological properties of deoxynivalenol (DON), nivalenol (NIV) and their acetylated derivatives require careful monitoring of the dynamics of these mycotoxins and their producers. The phylogenetic species concept has become a valuable tool to study the global occurrence of mycotoxin-producing Fusarium species. This has revolutionised our views on the terrestrial distribution of trichothecene-producing Fusaria in the context of agronomics, climatic conditions, and human interference by the global trade and exchange of agricultural commodities. This paper presents an overview of the dynamics of the different trichothecene-producing Fusarium species as well as their chemotypes and genotypes across different continents. Clearly not one global population exists, but separate ones can be distinguished, sometimes even sympatric in combination with different hosts. A population with more pathogenic strains and chemotypes can replace another. Several displacement events appear to find their origin in the inadvertent introduction of new genotypes into new regions: 3-acetyl-DON-producing F. graminearum in Canada; 3-acetyl-DON-producing F. asiaticum in Eastern China; 15-acetyl-DON F. graminearum in Uruguay; and NIV-producing F asiaticum in the southern United States.

Crops are a main driver for species diversity and the toxigenic potential ofFusarium isolates in maize ears in China

“…Although many reports on occurrence and prevalence of Fusarium species exist (reviewed by Van der Lee et al, 2015) and population structures are found to be changing over time, the drivers for this phenomenon are still largely unknown. Both climate and cropping systems have been suggested to play an important role, but comparative biological studies are scarce.…”

Population genetic analysis and trichothecene profiling of Fusarium graminearum from wheat in Uruguay

“…Nevertheless, the DON/NIV genotype was not detected in the current study. Also, the special interest in the rare NIV genotype is because NIV is more toxic than DON in most animal systems (van der Lee et al, 2015). The validation of trichothecene genotypes via chemical analyses can help to provide more reliable data on the trichothecene profile of fungal populations.…”

“…Additionally, the different trichothecene mycotoxins have different toxicological properties. For example, NIV is more toxic than DON to humans and domestic animals, and hence a stricter limit for the temporary tolerable daily intake of NIV than that of DON (0.7 µg/kg body weight for NIV; 1 µg/kg for DON) has been issued by the European Scientific Committee for Food (van der Lee et al, 2015). In Uruguay, only DON levels have been regulated in wheat grains and their by-products for human consumption (MSP, 2001).…”

Contrasting Roles of Deoxynivalenol and Nivalenol in Host-Mediated Interactions between Fusarium graminearum and Sitobion avenae

“…The prevalence of different F. graminearum chemotypes varies according to geographical region, with NIV chemotypes prevailing in Asia and DON chemotypes prevailing in Europe and North America [7,8]. The geographical distribution of the different chemotypes has also been recently described to be shifting, although the factors driving the change are not known.…”