Morpho-cultural and molecular phylogenetic characterisation of Curvularia verruculosa causing leaf spot and blight disease on Strychnos potatorum – A new record from India.

Strychnos potatorum L.f., is a well-known medicinal plant found in peninsular India and Sri Lanka, which is widely used in traditional and modern medicines for curing various kinds of diseases. In January 2020, while conducting a foliar fungal disease investigation in Kerala, India, a leaf spot and blight disease was spotted on S. potatorum. The pathogen was isolated and identified as Curvularia verruculosa based on symptomatic studies, culture characteristics, conidial morphology, multigene (ITS- LSU-GAPDH-TEF1-α) molecular sequences analysis, and concatenate multigene (ITS- GAPDH-TEF1-α) phylogeny. Koch's postulates were evaluated in vitro , and similar symptoms and re-isolation of the pathogen confirmed the association of C. verruculosa with leaf spot and blight disease. To our knowledge, this is the first report of C. verruculosa causing foliar disease on S. potatorum in India. [Display omitted] • Strychnos potatorum , recently faces a novel biotic threat causing leaf spot and leaf blight. • The pathogen was identified as Curvularia verruculosa by morphology and molecular studies. • Precise identification of this foliar pathogen could be helpful for disease management. [ABSTRACT FROM AUTHOR]