| 摘要 |
[Objectives] To elucidate the community composition of endophytic fungi in areca leaves affected by viral infection and explore the potential correlation between areca yellowing associated viruses and endophytic fungi. [Methods] Leaf samples from healthy, yellowing, and stunted areca palms were systematically collected in August 2025 from an orchard affected by yellow leaf disease (YLD) at Dongsheng Farm, Qionghai City, Hainan Province. The infection rates of areca palm velarivirus 1 (APV1), areca palm yellowing-associated ormycovirus (APYLaOMV), and areca palm latent totivirus 1 (APLTV1) were determined using RT-PCR assay. Endophytic fungi were isolated and purified through the tissue separation method, and species identification was conducted based on ITS sequencing and homology comparison using the NCBI database. [Results] No target viruses were detected in healthy leaves. In contrast, the detection rates of APV1, APYLaOMV, and APLTV1 in diseased leaves were 60%, 50%, and 30%, respectively. A total of 81 endophytic fungal strains were isolated from 13 samples and identified as belonging to 14 genera and 37 species, all within the phylum Ascomycota. Community structure analysis revealed that the endophytic fungal communities in healthy leaves were relatively simple at the class, order, and family levels, with Nigrospora as the dominant genus. In contrast, fungal diversity increased significantly in diseased leaves, where Phyllosticta emerged as the dominant genus. Furthermore, the composition of endophytic fungi varied markedly among different leaf tissues. In the mesophyll tissue of diseased leaves, Phyllosticta and Colletotrichum were co-dominant genera, whereas Fusarium predominated in the vein tissues. In healthy leaves, Nigrospora was the dominant genus in both mesophyll and vein tissues. [Conclusions] This study identifies the predominant viral species associated with YLD in areca palms and characterizes the community structure of leaf endophytic fungi in Qionghai City. It provides essential data and theoretical foundations for further elucidating the complex pathogenic mechanisms underlying YLD in areca palms, screening effective biocontrol fungi, and developing integrated management strategies. |
