Peach Buds’ Microbiome Profiling Reveals Cultivar-Specific Signatures Associated with TCSB Susceptibility

The plant microbiome plays a pivotal role in host development and resilience against biotic and abiotic stresses. In perennial crops like peach, microbial communities inhabiting dormant buds—critical yet vulnerable organs—may influence disease outcomes and plant fitness. This study characterized the bacterial and fungal communities associated with the buds of three peach cultivars differing in susceptibility to Twig Canker and Shoot Blight (TCSB). Amplicon-based profiling revealed distinct microbiome signatures across cultivars, shaped by host genotype. The highly tolerant ‘Catherina’ harbored a structured and relatively diverse community enriched in beneficial bacterial genera such as Pseudomonas, Sphingomonas, and Curtobacterium, alongside protective yeasts including Aureobasidium and Cladosporium. In contrast, the susceptible cultivar ‘Pavoro®-Pav 1605’ hosted a less balanced microbiome, marked by enrichment of opportunistic pathogens such as Alternaria and Diaporthe, as well as the bacterial lineage 1174-901-12. The intermediate cultivar ‘Lami®.COM’ displayed a transitional profile enriched in Sphingomonas, Pelomonas, and Vishniacozyma. Differential abundance analyses confirmed cultivar-specific enrichment patterns, underscoring the influence of genotype in shaping microbiota composition and potential disease outcomes. These findings support the integration of microbiome-based approaches into sustainable disease management via beneficial microbial promotion, early detection of harmful consortia, and microbiome-informed breeding to foster resilient, low-input peach cultivation systems.