A PCR-RFLP based diagnostic technique to rapidly identify Seiridium species causing cypress canker

Area of Science:

• Mycology
• Plant Pathology
• Molecular Diagnostics

Background:

• Cypress canker, a disease affecting Cupressus species, is caused by three distinct fungi: Seiridium cardinale, S. cupressi, and S. unicorne.
• Current methods, including morphological examination and ribosomal DNA sequencing, are unreliable for differentiating these Seiridium species.
• Accurate identification of these fungal pathogens is crucial for managing threats to Cupressaceae trees.

Purpose of the Study:

• To develop a simple and reliable method for distinguishing between Seiridium cardinale, S. cupressi, and S. unicorne.
• To provide a cost-effective diagnostic tool for identifying key Seiridium species responsible for cypress canker.

Main Methods:

• A restriction fragment length polymorphism (RFLP) assay was developed.
• The assay targets the beta-tubulin gene, amplifying it and then digesting the amplicons with the endonuclease HaeIII.
• The resulting fragment patterns were analyzed to differentiate the fungal species.

Main Results:

• The RFLP assay successfully distinguished between the three Seiridium species.
• Digestion with HaeIII produced unique fragment patterns for each species, allowing for clear identification.
• This method proved to be a simple and inexpensive diagnostic approach.

Conclusions:

• The described RFLP assay provides an effective means for differentiating Seiridium cardinale, S. cupressi, and S. unicorne.
• This diagnostic tool is valuable for identifying serious threats to trees within the Cupressaceae family.
• The assay offers a practical solution for accurate cypress canker pathogen identification in research and management settings.