Abstract:

Wheat Fusarium crown rot has become a major soil-borne disease that threatens the safety of wheat production in the Huang-Huai wheat region and the Guanzhong wheat region in China. Its occurrence is closely related to the imbalance of soil microecology, but the mechanism of soil physicochemical properties and microbial community synergistically driving the disease is still unclear. This study aimed to clarify the relationship between the occurrence of Fusarium crown rot and the soil micro-ecological environment. Wheat and soil samples from diseased and healthy fields in the wheat-producing region of Guanzhong, Shaanxi Province were collected as the research materials. The differences in soil physicochemical properties, microbial community structure and wheat growth were then analyzed and compared. The results showed that the contents of total nitrogen, available nitrogen, available phosphorus and available potassium in diseased soils were 10.9%, 9.2%, 25.1% and 16.0% higher than those in healthy soils, respectively. The distribution of dominant bacterial and fungal communities was more balanced in healthy soils, with Cladosporium, Vishniacozyma and Micrococcaceae identified as the core beneficial taxa. Pathogenic fungi such as Fusarium and Alternaria dominated in diseased soils. Compared with diseased wheat, healthy wheat exhibited increases of 26.4% in plant height, 8.7% in spike length, and 64.9% in flag leaf area, respectively. Correlation analysis revealed that soil nutrients indirectly affect the occurrence of the disease by regulating microbial community composition. This study revealed the pathogenic chain of ‘high nutrient enrichment-pathogen advantage-microecological imbalance-wheat victimization’ in Guanzhong wheat area, and proposed a coordinated prevention and control strategy of ‘nutrient regulation coupled with microbial community optimization’. The potential biocontrol bacteria resources were clarified, and provided scientific support for the green prevention and control of wheat Fusarium crown rot, soil health improvement and high-yield cultivation. In the future, the research on the coupling technology of microbial agent creation and precision fertilization can be carried out.

Key words: wheat Fusarium crown rot, soil microecology, soil physicochemical properties, microbial community, Fusarium, nutrient regulation, Guanzhong wheat area