Anastomosis groups and molecular variation in Pseudocercospora griseola

Area of Science:

• Plant Pathology
• Mycology
• Genetics

Background:

• Angular leaf spot, caused by Pseudocercospora griseola, is a significant disease in common beans (Phaseolus vulgaris L.).
• Understanding pathogen variability is key to developing resistant cultivars.
• The mechanisms driving P. griseola variability, particularly asexual recombination, are not fully understood.

Purpose of the Study:

• To identify hyphal fusion (anastomosis) among P. griseola isolates.
• To evaluate the genetic variability of P. griseola isolates using anastomosis groups and Random Amplified Polymorphic DNA (RAPD) markers.

Main Methods:

• Inoculation of differential bean cultivars.
• Molecular analysis using RAPD markers.
• Observation and analysis of hyphal anastomosis between P. griseola isolates.

Main Results:

• Hyphal anastomosis was observed in all P. griseola isolates, with some exhibiting high compatibility.
• Sixteen distinct anastomosis groups were identified, indicating significant variability in hyphal fusion.
• High genotypic variability was detected using RAPD markers, but no correlation was found between genotype and anastomosis group.

Conclusions:

• This study provides the first report of anastomosis in P. griseola, highlighting its role in pathogen variability.
• The observed genetic diversity is crucial for breeding angular leaf spot-resistant common bean varieties.
• Further research is needed to fully understand asexual recombination processes in this phytopathogen.