Characterization of Fusarium crown rot pathogens and trichothecene genotypes in wheat crops of Hebei province, China

This study identifies and characterizes pathogenic Fusarium species and their trichothecene genotypes in wheat crops grown in seven regions of Hebei Province, China, from 2019 to 2021. Species-specific primers confirmed the morphological identification of 689 Fusarium strains recovered from wheat seedlings with symptomatic crown/sub-crown tissues. The results suggest that Fusarium pseudograminearum was the most detected strain, accounting for 91 % of the identified strains. Other species, including F. graminearum, F. oxysporum, F. proliferatum, F. asiaticum, and F. culmorum, were detected at lower rates, ranging from 0.15 % to 8.56 %. Toxin genotype detection results showed that F. pseudograminearum and F. graminearum were the most common species linked to wheat crown rot, producing high detection rates of trichothecene genotypes. F. pseudograminearum strains had detection rates of 84.50 % for deoxynivalenol (DON) and other mycotoxins, including 3-acetyl-deoxynivalenol (3-AcDON) and 15-acetyl-deoxynivalenol (15-AcDON). On the other hand, strains (F. graminearum) of the 15-AcDON chemotype were detected at 15 L-AcDON, with detection rates of 34.37 %, 21.88 %, 21.88 %, and 18.75 % in Handan, Shijiazhuang, Xingtai, and Baoding, respectively. The study also indicated that F. pseudograminearum and F. graminearum had strong pathogenicity, while F. asiaticum and F. culmorum showed weak pathogenicity to wheat in Hebei Province. This study identifies F. pseudograminearum as the predominant cause of Fusarium crown rot in Hebei Province, with the majority of strains classified as DON genotypes.