Improved detection of rice yellow mottle virus with a polyclonal antibody xMAP assay: A High-Throughput Alternative to ELISA

While mABs failed to retain their expected serotype specificity in the xMAP format, the polyclonal antibody enabled robust and strain-independent detection of RYMV. The pAB-based xMAP assay showed excellent diagnostic performance, with 100% specificity, sensitivity exceeding 97%, and an area under the ROC curve of 0.99. Importantly, the pAB-based xMAP assay demonstrated a 100-to 500-fold increase in sensitivity compared with DAS-ELISA, allowing reliable detection of RYMV in samples with low viral loads or compromised integrity. No cross-reactivity was observed with other co-circulating rice viruses, including maize streak virus and rice stripe necrosis virus. This study demonstrates that a polyclonal antibody-based xMAP immunoassay provides a highly sensitive, specific, and scalable alternative to conventional ELISA for RYMV diagnosis. This approach represents a promising tool for large-scale epidemiological surveys and improved management of rice viral diseases in Africa.