リアルタイム定量PCR法によるチャ炭疽病菌の定量検出

抄録

Anthracnose is the most important disease of tea caused by Discula theae-sinensis (I. Miyake) Moriwaki & Toy. Sato (Dts). The most widely planted tea cultivar ‘Yabukita’ is susceptible to anthracnose and is important to the establishment of an efficient technique to control the disease. In this study, we attempted quantitative detection of Dts by real-time quantitative PCR (qPCR) for use in epidemiological studies of this pathogen. We designed Dts-specific primers based on the 28S ribosomal RNA gene sequence and assessed their specificity. We confirmed the high specificity of the primers because no amplification was observed for Dts related species or other major tea-pathogenic fungi. We used DNA extracted from serial dilutions of a conidial suspension as the template to generate a calibration curve and obtained a calibration curve with high linearity in the range of approximately 2 × 10² to 2 × 10⁷ conidia/mL. We applied the qPCR method to quantify Dts in ground leaf disks taken from diseased and symptomless tea leaves. Use of this method to quantify Dts conidial dispersal at each developmental stage of tea will assist in determining the optimum timing for control of anthracnose.