Comparison of Rhizosphere Fungal Community Changes in Healthy and Yellowing-Leaf-Disease-Affected Areca Palms by High-Throughput Sequencing Technology

Yellow leaf disease (YLD) has been the most severe disease threatening areca palm, commonly known in areca palm cultivation. However, it has not yet been systematically studied in terms of the relationship between infected plants and the structure of rhizosphere microbial communities. In order to systematically study the impact of YLD on the rhizosphere fungi of the areca palm, we implemented high-throughput sequencing technology to analyze the microbial community structure and diversity under different disease conditions. The results indicate that as the severity of the disease increases, the diversity of the fungal community diminishes, with species abundance and richness initially decreasing before subsequently increasing, while phylogenetic diversity increases, and significant changes occur in the structure of the soil fungal community. At the phylum level, the dominant fungal phyla in the rhizosphere of areca palm are <i>Ascomycota</i> and <i>Basidiomycota</i>. At the genus level, the dominant genera are <i>Sarocladium</i>, <i>Roussoella</i>, <i>Penicillium</i>, etc., and their relative abundance increases with the severity of the disease. LEfSe analysis revealed that <i>Archaeorhizomyces</i>, <i>Codinaea</i>, and <i>Albifimbria</i> serve as indicator species for healthy areca palms, with their relative abundance trends consistent with changes in Alpha diversity. FUNGuild prediction results indicated that the fungal nutrient type structures of the three rhizosphere samples were highly similar, with saprotrophs being the absolutely dominant type. With the increase in the severity of the disease, the number of harmful fungi in the soil (such as <i>Plectosphaerella</i>, <i>Fusarium</i>, etc.) increases, thereby limiting the sustainable development of the soil. Network analysis indicates that beneficial microbial communities such as <i>Stachybotrys</i> and <i>Roussoella</i> exhibit extensive negative interactions. Therefore, the YLD of areca palm significantly alters the structure and diversity of the rhizosphere fungal community. Simultaneously, some beneficial microorganisms may be recruited by the areca rhizosphere to resist the invasion of YLD by improving the rhizosphere environment and enhancing plant immunity, such as <i>Trechispora</i>, <i>Saitozyma</i>, and <i>Marasmiellus</i>. This experiment is expected to provide a theoretical basis for the study of the rhizosphere microecology of the areca palm, the exploration of excellent biocontrol resources, and the green control of YLD in the areca palm.