Four Decades of Genomic Stability and Adaptive Divergence in Xanthomonas arboricola pv. pruni -Infecting Phages: Defining Duraznoxanthovirus arenicola and Its Evolutionary Framework

Bacteriophages (phages) are abundant and ecologically significant, yet their diversity and roles in plant-associated ecosystems remain poorly understood, limiting their application in sustainable disease management. To address this gap, we characterized 15 phages infecting Xanthomonas arboricola pv. pruni , the causal agent of bacterial spot on peach, has been isolated for over four decades from North Carolina orchards. Comparative genomic and phylogenetic analyses revealed two temporally distinct clades with >95% nucleotide identity and 63 conserved core genes, forming a new genus and species, Duraznoxanthovirus arenicola . These findings challenge assumptions of pervasive genomic mosaicism, highlighting remarkable genomic stability alongside localized variability in accessory loci. Beyond genus-level characterization, our analyses support a broader taxonomic restructuring within the family Anamaviridae , introducing a new subfamily ( Terravirinae ) and two new genera ( Duraznoxanthovirus and Ralstopathovirus ). This work provides the first family-level framework for phages exclusively infecting plant-associated bacteria, offering evolutionary insights and a foundation for ecological studies and management strategies.