交叉引物扩增结合分子信标荧光法用于柑橘黄龙病病原体现场检测研究

Abstract

Huanglongbing (HLB), a devastating citrus disease with no known cure, necessitates early on-site detection for effective disease management. However, current diagnostic methods remain limited by suboptimal detection rates, biosafety concerns, and lack of portability. This study presents the HLB-OSD system, a field-ready, portable heating and fluorometric device for the rapid, on-site identification of Candidatus Liberibacter asiaticus (CLas), the causative agent of HLB. The system integrates cross-priming amplification with highly specific molecular beacon probes in a single-tube, isothermal (63 °C) assay, enabling the direct detection of CLas from crude citrus leaf DNA extracts within 25–40 min without complex instrumentation. With 8.3 copy/μL detection limit and no cross-reactivity, the assay showed 94.24% concordance with qPCR (180/191). Field validation in Yongxiu county, a key HLB containment buffer zone in northern Jiangxi Province, confirmed a 9.0% (44/487) infection rate. Our on-site system provides lab-accurate detection, enabling timely monitoring of HLB for citrus protection.