Acidomelania saccharicola sp. nov., a new species of dark septate endophytes in Helotiales, with potential of controlling Fusarium wilt of banana

• A. saccharicola LZ3 represents a new species of Acidomelania . • Banana plants inoculated with LZ3 exhibits reduced levels of Fusarium wilt. • LZ3-Banana symbionts exhibit increased POD and SOD activity. • LZ3-Banana symbionts exhibit reduced MDA content and less symptoms of banana wilt. Banana wilt-like disease, triggered by Fusarium oxysporum , poses a severe threat to banana cultivation as a persistent soilborne pathogen. A strategy to effectively control this disease has yet to be found. Dark septate endophytes (DSEs) fungi have emerged as promising biocontrol agents, not only offering protection against plant pathogens but also enhancing plant growth. Herein, we isolated a novel DSEs species, Acidomelania saccharicola LZ3, from sugarcane ( Saccharum officinarum ) soil in Liuzhou, Guangxi Province, China. Its classification as a new species was confirmed through morphological characterization and DNA sequence analysis. A. saccharicola LZ3 promoted the growth of banana and inhibited the growth of F. oxysporum by 73.28% in a Petri dish assay, and reduced disease by 52.82% in pots. The average incidence rate of Banana-LZ3 symbionts transplanted into a field highly contaminated with F. oxysporum was 25.93% and the control effect was 53.27%. Inoculation of banana plants with A. saccharicola LZ3 significantly increased polyphenol oxidase (POD) and superoxide dismutase (SOD) activity. This research lays the groundwork for future investigations into A. saccharicola and other DSEs, exploring their potential in sustainable plant disease management.