Colletotrichum gloeosporioides sensu lato (s.l.) is one of the most economically and scientifically important fungal pathogens, causing serious diseases in tropical and subtropical region. The detection of C. gloeosporioides s.l. is of importance for disease control. In this study, an ACT-based real-time PCR assay was developed for quantification of C. gloeosporioides s.l., which reliably detected as little as 100 fg genomic DNA, 100 copies of target DNA and 20 conidia. This method could recognize all four tested C. gloeosporioides s.l. isolates, while no amplification was observed in other Colletotrichum species and Botrytis cinerea, indicating the specificity of this assay. Detection and quantification of C. gloeosporioides s.l. was demonstrated in artificially and naturally infected host leaves. First, the real-time PCR analysis was performed using leaf samples collected at different time points post inoculation to monitor the growth of C. gloeosporioides s.l. over time. Secondly, the method was used to compare the resistance in two Stylosanthes cultivars and two Arabidopsis cultivars. Finally, naturally infected and symptomless leaves of Stylosanthes in the fields were tested by the real-time PCR method. Overall, the real-time PCR assay could allow the detection at early symptomless phase of infection; and the results was well correlated with microscopic observation and later disease symptoms. Therefore, our studies have provided a rapid and effective detection method for studying the plant-Colletotrichum interaction as well as disease prediction and control.

Colletotrichum gloeosporioides sensu lato (sl) 是最经济和科学上最重要的真菌病原体之一，在热带和亚热带地区引起严重的疾病。C. gloeosporioides sl的检测对于疾病控制具有重要意义。在这项研究中，开发了一种基于 ACT 的实时 PCR 检测方法来定量C. gloeosporioides sl，它可靠地检测到低至 100 fg 基因组 DNA、100 个目标 DNA 拷贝和 20 个分生孢子。该方法可以识别所有四种测试的C. gloeosporioides sl 分离物，而在其他炭疽菌属物种和灰霉病菌中未观察到扩增，表明该测定的特异性。在人工和自然感染的宿主叶子中证明了C. gloeosporioides sl的检测和定量。首先，使用在接种后不同时间点收集的叶样品进行实时 PCR 分析，以监测C. gloeosporioides sl 随时间的生长。其次，用该方法比较了两个柱花草品种和两个拟南芥品种的抗性。最后，柱花草的自然感染且无症状的叶子田间采用实时荧光定量 PCR 方法进行检测。总体而言，实时 PCR 检测可以在感染的早期无症状阶段进行检测；结果与镜下观察和后期疾病症状有很好的相关性。因此，我们的研究为研究植物-炭疽菌的相互作用以及疾病的预测和控制提供了一种快速有效的检测方法。