Rapid Detection of Colletotrichum lagenarium, Causal Agent of Anthracnose of Cucurbitaceous Crops, by PCR and Real-time PCR

Rapid and accurate polymerase chain reaction (PCR) and real-time PCR methods were developed for the detection of Colletotrichum lagenarium, the causal agent of anthracnose, in tissues of squash (Cucurbita moschata), watermelon (Citrullus lanatus), cucumber (Cucumis sativus) and muskmelon (Cucumis melo). PCR assays amplified different internal transcribed spacer sequences from C. lagenarium, so effectively detected this pathogen in infected tissues. PCR analysis with the primer co-m-337F1/R1 was able to differentiate C. lagenarium from other fungal pathogens, including Colletotrichum spp., Fusarium spp., Alternaria spp. and Didymella spp. An optimized real-time PCR assay was developed to detect and monitor C. lagenarium in both infected plant tissues and soil samples. The sensitivity of real-time PCR can detect down to 1 pg of DNA. Thus, PCR-based analysis is a useful technique for rapid detection and diagnosis of C. lagenarium in infected plants or infested soils.