Characterizing fungal community shifts associated with

Introduction: Fungal communities are central elements of phytobiomes, yet their roles in mediating plant-insect interactions remain poorly understood. Here, we addressed this knowledge gap in quinoa, which has recently suffered significant losses due to a stem-boring pest. Methods: We used culture-based isolation from stems and amplicon-based profiling of rhizosphere soils to characterize quinoa-associated fungi across six site-year combinations in Colorado and to relate community patterns to abundance of stem-boring fly Results: Eighteen stem endophytes dominated by Ascomycota were isolated. Soil sequencing resolved 23 core amplicon sequence variants detected across all site-years; the core was primarily Ascomycota, with Discussion: These results indicated that community composition impacted pest pressure, with pathogenic fungi coinciding with higher fly abundance and entomopathogenic fungi enriched where larval pressure was lower. These findings identify candidate taxa for microbiome-informed integrated pest management and underscore the potential of site-specific practices (e.g., intercrops, organic amendments) to foster fungal communities that enhance quinoa resilience.