Recombinase Polymerase Amplification Assay for Simultaneous Detection of Maize Chlorotic Mottle Virus and Sugarcane Mosaic Virus in Maize.

Maize chlorotic mottle virus (MCMV) can cause maize lethal necrosis (MLN) when coinfected with potyvirids, such as sugarcane mosaic virus (SCMV), maize dwarf mosaic virus, or wheat streak mosaic virus. MLN is often caused by coinfection of MCMV and SCMV, which has been reported in China and several countries of Africa. In this study, a recombinase polymerase amplification (RPA) assay was established for simultaneous detection of MCMV and SCMV in maize. The RPA assay can be completed within 30 min at 38 °C. The primers for the RPA assay were specific since no crossreaction was detected with other selected viruses that infected maize in China. The detection limit of the RPA method was 10 copies μL, which was about 10-fold more sensitive than that of the conventional PCR method. Moreover, the RPA assay can be successfully applied to detect maize samples collected in the field. These results demonstrated that the established RPA assay is a rapid and efficient method to conduct simultaneous detection of MCMV and SCMV, which provides an alternative technology for MLN diagnosis.