Morpho-molecular investigation reveals first report of Corynespora cassiicola causing red leaf spots on Trema orientale from India

Trema orientale has been used for various purposes due to its potential medicinal properties. A red leaf spot disease was observed on T. orientale in Peechi-Vazhani Wildlife Sanctuary, Kerala, India, with 33.33% disease incidence. The fungus was isolated from the diseased leaf sample, producing brownish colonies on PDA. The same fungus was inoculated, re-isolated and identified from diseased leaves after the in vitro pathogenicity test, which showed the pathogenic nature of the isolated fungus, thus fulfilling Koch’s postulates. Based on cultural and morphological characteristics followed by rDNA – Internal Transcribed Spacer (ITS)-based molecular analysis, the pathogen was identified as Corynespora cassiicola (Corynesporascaceae). To the best of our knowledge, C. cassiicola is reported here for the first time on T. orientale from India. The study emphasizes the need for further investigations on climate – host – pathogen interactions and the development of effective management strategies for the disease.