Characterization and pathogenicity of Stemphylium symphyti causing leaf spot on pennyroyal (Mentha pulegium L.)

Abstract

Pennyroyal (Mentha pulegium L.), is a member of the Lamiaceae family. During the summer of 2018, in order to identify the causal agent, pennyroyal leaves with round to spindle and dark brown to black spots with white centers were collected from Zayandeh Rud riversides of the Eail Bagi village, Chaharmahal and Bakhtiari province, Iran. The morphological and the molecular identification of the recovered fungal isolate was performed based on the partial sequence of the glyceraldehyde-3-phosphate dehydrogenase (gpdh) region. The fungal isolate was finally identified as Stemphylium symphyti. In the pathogenicity test, the Koch’s postulates were performed in a greenhouse, and the same leaf spot symptoms were observed in the inoculated leaves of the pennyroyal plants and S. symphyti was re-isolated. Stemphylium symphyti is a new taxon for funga of Iran, and this is the first report of S. symphyti causing leaf spot in the M. pulegium leaves in the world.

Keywords:

• Fungus
• morphology
• gpdh
• biodiversity
• Iran

Declaration of interest statement

Competing interests

The authors have no relevant financial or non-financial interests to disclose.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Disclosure statement

No potential conflict of interest was reported by the authors.