Fungal community structure in date palm cultivars of Oman: Insights into diversity and potential interspecific competition

Abstract Fungal diseases have a great impact on yield reduction of date palm. However, certain fungi establish symbiotic association with date palm, helping in plant growth under water stress conditions. It is also possible that fungal species inhabiting different tis-sues of date palm may produce antimicrobial substances that might prevent the growth of pathogenic fungi and bacteria. Therefore, investigating the fungal diversity in date palm cultivars and understanding the potential interspecific competition is crucial. In this study, we investigate the fungal diversity residing in rhizosphere, roots, and leaves of two cultivars of date palm, Khalas (KH) and Naghal (NG), and from two different locations, Sohar and Samail, located in northern Oman. Sohar is a coastal region, while Samail is located in the interior of the country. Using Illumina MiSeq high-throughput sequencing (2 × 300 flow cell), we characterized the diversity and relative abundance of fungal taxa across different tissues, cultivars, and location. This study did not explicitly identify antifungal-producing or non-antifungal strains through interspecific competition assays, however, the data suggest the presence of competitive interactions among fungal taxa. Specifically, stronger niche competition appeared to occur when multiple fungal phyla coexisted. For example, in one location, Basidiomycota dominated in a cultivar where Ascomycota was notably absent, indicating potential competitive exclusion between these phyla. It is concluded from this study that fungal diversity varies in date palm tissues, cultivars and locations, and further suggests potential interaction among major fungal groups play a key role in shaping these communities.