Effects of Chaetomium globosum and Trichoderma asperellum on root configuration and growth of cucumber seedlings

In order to investigate the effects of Acer truncatum endophytic fungi Chaetomium globosum and Trichoderma asperellum on root configuration and growth of cucumber seedlings, "Xinjin No. 4" was used as experimental material and pot experiment was conducted. The experiment was set up with four treatments: a blank control (CK), a treatment with Chaetomium globosum at 100% concentration (CG), a treatment with Trichoderma asperellum at 100% concentration (TA), and a mixed strain treatment combining 50% Chaetomium globosum and 50% Trichoderma asperellum administered via root irrigation (GA). The effects of growth, root morphology, topological structure and typing parameters on root growth and development of Cucumis sativus L. (Xinjin No. 4) were studied. The results showed that, compared with the control group, the total root length, root surface area, root volume, cross number, plant height, stem diameter and biomass of cucumber seedlings treated with fungi solution were significantly increased, and the mixed fungi solution had the most significant effect on cucumber seedlings. The root system treated with fungi solution had obvious branching characteristics, such as forked branch structure, good fractal characteristics, small fractal dimension and high fractal abundance, indicating that its branch structure was relatively simple and had good expansion space, which was beneficial to occupying nutrient space. Soil water content, soil bulk density, soil porosity, soil capillary porosity and soil ventilation were the highest after the application of mixed fungi. The dominant particle size of aggregates of soil water stability under different treatments was 0.5-1 mm. The soil water stability, i.e. WR_0.25 (the content of water-stable aggregates larger than 0.25 mm), mean weight diameter (MWD) and geometric mean diameter (GMD) values, were significantly increased after treatment with mixed fungi compared with the control group (p < 0.05), and the soil structure was more stable. In conclusion, single application of Chaetomium globosum or Trichoderma asperellum could significantly promote the growth of cucumber seedlings, but the effect of mixed solution was better than that of single solution, offering potential applications for sustainable agricultural practices to enhance crop productivity and soil health.