Abstract:The adaptability of Fusarium graminearum and Fusarium asiaticum to three different host plants (wheat, maize, and Asian cultivated rice) was investigated. Strains from different geographic origins in China were isolated based on their 3ADON or 15ADON trichothecene chemotype. The results displayed that the F. graminearum strains from Hubei, Anhui, Jiangsu, and Hebei exhibited the 15ADON chemotype, whereas the F. asiaticum strains from Hubei, Anhui, Jiangsu, and Fujian displayed the 3ADON chemotype. All strains were cultured on wheat straw (WA), maize straw (MA), and rice powder (RA) substrates at 25 and 15 ℃ separately. The growth rates of all strains were found to be highest on WA substrate, whereas they were significantly decreased on MA and RA substrates. In particular, at 25 ℃, the growth rates at 25 ℃ for F. graminearum and F. asiaticum decreased by 25.75% and 35.06% on MA, and 25.88% and 24.97% on RA, respectively, compared with those on WA. Similarly, at 15 ℃, the growth rates reduced by 23.01% and 25.22% on MA, and 27.16% and 23.71% on RA, respectively. By comparing the perithecial biomasses produced by each strain on wheat straw (WS), maize straw (MS), and rice straw (RS), WS was observed to be the most suitable host for perithecial formation for both F. graminearum and F. asiaticum strains. Simultaneously, F. graminearum was found to demonstrate a higher adaptability to MS than to RS, whereas F. asiaticum was more adaptable to RS than MS. The research findings demonstrate that F. graminearum and F. asiaticum exhibit distinct adaptability to the three host plants described above. The research results can provide theoretical guidance for preventing Fusarium head blight and reducing Fusarium mycotoxin contamination in grains at the source.
