Soil Microeukaryote Diversity in the Crop Fields of Panama.

Soil microeukaryotic communities are essential for nutrient cycling and the maintenance of soil fertility, yet their diversity in tropical agricultural systems remains poorly characterized. In this study, high-throughput metabarcoding of the V4 region of the 18S rRNA gene was used to characterize soil microeukaryotic communities across three agricultural regions of Panama. A total of 7714 unique operational taxonomic units (OTUs) were detected in composite soil samples collected from 44 sampling sites. The high-altitude region showed significantly greater species richness and distinct community composition compared with the lowland regions. Principal coordinate analysis identified two major clusters separating the high-altitude and lowland regions. Correlation analyses revealed associations between eukaryotic diversity and soil properties, particularly phosphorus content, electrical conductivity, and terrain slope. Taxonomic assignments, particularly at the species level, should be interpreted cautiously because they are based on 18S rRNA gene metabarcoding and OTU-based classification. These findings contribute to the characterization of soil microeukaryotic diversity in tropical agricultural fields and may support the integration of biodiversity assessments into soil management.