A Duplex PCR Assay for Rapid Detection of and .

A duplex PCR method was developed for simultaneous detection and identification of tobacco root rot pathogens and . The specific primers for were developed based on its internal transcribed spacer (ITS) regions of ribosomal gene, gene and gene, while the specific primers for were designed based on its ITS regions and tubulin gene. The specificity of the primers was determined using isolates of , and control samples. The results showed that the target pathogens could be detected from diseased tobacco plants by a combination of the specific primers. The sensitivity limitation was 100 fg/μl of pure genomic DNA of the pathogens. This new assay can be applied to screen out target pathogens rapidly and reliably in one PCR and will be an important tool for the identification and precise early prediction of these two destructive diseases of tobacco.