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Published on: October 23, 2011
Development of a Multiplex PCR to Simultaneously Detect Four Problematic Pathogens in Cymbidium kanran
Jiwon Kim1, Sunyung Yoon2, Seungtae Kang3
1Subtropical/Tropical Organism Gene Bank, Jeju National University, Jeju 63243, Korea.
Abstract:
Colletotrichum gloeosporioides (Cg), Pestalotiopsis sp. (Ps), Fusarium oxysporum (Fo), and Fusarium proliferatum (Fp) are pathogens that cause various diseases of Cymbidium kanran. Species identification based on the morphological characteristics of pathogen-infected orchids is very complex and difficult; therefore, specific and reliable diagnostic methods are needed. Here, we developed a multiplex polymerase chain reaction (PCR) assay for simultaneous detection of Cg, Ps, Fo, and Fp. Four pairs of pathogen-specific primers were designed based on the internal transcribed spacer sequences of each pathogen, generating fragments of 480, 407, 321, and 279 bp, respectively. The multiplex PCR assay using these four pairs of mixed primers effectively detected the four pathogens simultaneously, with a sensitivity of 0.1 ng genomic DNA/pathogen. Application of the optimized multiplex PCR assay to symptomatic C. kanran leaf samples effectively detected single or multiple pathogens. These results indicate that the multiplex PCR developed in this study is not only a rapid and reliable method for detecting four problematic pathogens in C. kanran, but also serves as a very useful tool for early diagnosis.
Insights
A new multiplex PCR method accurately detects four major pathogens affecting Cymbidium kanran orchids. This rapid diagnostic tool aids in the early identification of Colletotrichum gloeosporioides, Pestalotiopsis sp., Fusarium oxysporum, and Fusarium proliferatum.
Area of Science:
- Plant Pathology
- Molecular Diagnostics
- Mycology
Background:
- Cymbidium kanran orchids are susceptible to diseases caused by multiple fungal pathogens.
- Accurate identification of pathogens like Colletotrichum gloeosporioides, Pestalotiopsis sp., Fusarium oxysporum, and Fusarium proliferatum is challenging using traditional morphological methods.
Purpose of the Study:
- To develop a rapid, specific, and reliable multiplex polymerase chain reaction (PCR) assay for the simultaneous detection of four key C. kanran pathogens.
- To provide an effective tool for early diagnosis and management of orchid diseases.
Main Methods:
- Design of four pairs of pathogen-specific primers targeting internal transcribed spacer (ITS) sequences.
- Development of a multiplex PCR assay for simultaneous amplification of target DNA fragments.
- Optimization of the multiplex PCR assay for sensitivity and specificity.
- Validation of the assay using symptomatic C. kanran leaf samples.
Main Results:
- The multiplex PCR assay successfully detected Colletotrichum gloeosporioides, Pestalotiopsis sp., Fusarium oxysporum, and Fusarium proliferatum simultaneously.
- Specific DNA fragments of 480 bp (Cg), 407 bp (Ps), 321 bp (Fo), and 279 bp (Fp) were generated.
- The assay demonstrated a high sensitivity, detecting as little as 0.1 ng of genomic DNA per pathogen.
- The method effectively identified single or multiple pathogens in infected C. kanran leaf samples.
Conclusions:
- The developed multiplex PCR assay is a rapid, reliable, and sensitive tool for the simultaneous detection of four major pathogens in Cymbidium kanran.
- This method significantly improves diagnostic capabilities, enabling early detection and potentially better disease management strategies for C. kanran.
- The assay provides a valuable advancement over traditional morphological identification methods for orchid pathogens.

