Host-Informed MaxEnt Modeling Reveals Distinct Global Distribution and Redistribution Patterns of Four Major Fusarium graminearum Species-Genotype Groups Under Current and Future Climates.

The Fusarium graminearum species complex (FGSC) is a major causal agent of Fusarium head blight (FHB) and trichothecene contamination in cereal cropping systems worldwide. However, its major species-genotype groups exhibit distinct differences in environmental adaptability and spatial distribution. Using a host-informed MaxEnt modeling framework, this study compared the global potential environmental suitability of four major FGSC groups, namely Fusarium asiaticum-DON (Fa-DON), Fusarium asiaticum-NIV (Fa-NIV), Fusarium graminearum-DON (Fg-DON), and Fusarium graminearum-NIV (Fg-NIV), under the 1970-2000 baseline and four SSPs across four future periods. By integrating georeferenced occurrence records with continuous host-related, climatic, soil, topographic, and wind predictors, and applying four-fold spatial cross-validation, we identified distinct intergroup suitability patterns. Under current conditions, Fg-DON showed the broadest highly suitable area, whereas Fa-DON was the most restricted. Both F. asiaticum groups were centered in Asia, while Fg-NIV was concentrated mainly in Europe. Future projections indicated consistent expansion for Fg-DON and general contraction for Fa-DON. Fa-NIV remained comparatively stable, whereas Fg-NIV showed scenario-dependent contraction or expansion. These changes reflected regional redistribution rather than a uniform shift across groups. Collectively, our findings indicate that FGSC suitability should be interpreted as a set of differentiated, group-specific biogeographic patterns, which provide a more targeted scientific basis for surveillance strategies and regional risk assessment of FHB and trichothecene contamination under changing environmental conditions.