First report of Diplodia seriata de Not. causing black rot of apple (Malus domestica L. Borkh.) in Meghalaya, North Eastern India

Abstract

In a survey conducted during Januray-May, 2020, apple trees showing characteristic symptoms of frogeye leaf spots, canker and twig die back that in severe cases causing dead branches and severe defoliation have been observed from apple plantation of Umiam, Meghalaya. Isolation of the associated causal fungal agent was done in selective media and its cultural, morphological as well as microscopical studies were carried out. Furthermore, confirmation of the putative fungus was done by conducting pathogenicity test to prove Koch’s postulate. From the available literature, the fungus associated with the disease symptom have been identified as Diplodia seriata causing black rot of apple. To the best of the knowledge, this is the first report of isolation and pathogenicity confirmation of black rot of apple caused by D. seriata from Meghalaya, India.