Abstract

Banana blood disease, caused by Ralstonia syzygii subsp. celebesensis (Rsc), is one of the most destructive bacterial wilts affecting banana (Musa spp.) in Indonesia and Southeast Asia. Despite its economic importance, knowledge of the pathogen’s molecular characteristics and epidemiology has been limited compared to other members of the Ralstonia solanacearum species complex (RSSC). This study investigates the genomic features, population diversity, and molecular detection of Rsc to support effective management strategies. Draft genome sequencing of isolates collected from Sulawesi, Sumatra, and Kalimantan revealed unique genomic regions, including effector proteins and metabolic pathways, that distinguish Rsc from other RSSC taxa. Comparative analyses confirmed that Rsc represents a distinct evolutionary lineage, underscoring the need for pathogen-specific approaches. To enhance early detection, species-specific primers were designed targeting conserved loci and genes associated with volatile compound biosynthesis. These primers demonstrated high specificity and sensitivity in PCR assays, enabling reliable detection of Rsc in planting material and field samples. Application in epidemiological surveys indicated a broad but heterogeneous distribution of Rsc, reflecting both clonal expansion and local adaptation. Pathogenicity tests further validated symptom development and vascular colonization unique to Rsc, including characteristic bloody exudates. Overall, this research advances understanding of the biology and epidemiology of Ralstonia syzygii subsp. celebesensis. The combination of genomic resources, molecular diagnostics, and population studies provides essential tools for disease surveillance and informs integrated management strategies to mitigate banana blood disease in Indonesia and the wider region.