Characterization of Agroathelia rolfsii Causing Fruit Rot Disease in Jackfruit

Abstract

Symptoms of characteristic rot was observed on jackfruits (Artocarpus heterophyllus) of Thrissur district in Kerala. This study investigates, the symptomatology, pathogenicity and identification of the causal organism for fruit rot disease. The isolation of fungal sample was obtained from Thrissur district during the month of November 2023. The isolated fungus was successfully grown on potato dextrose agar medium and was characterized. Based on its cultural, morphological traits and molecular characterization, the fungus was identified as Agroathelia rolfsii (teleomorph: Athelia rolfsii, anamorph: Sclerotium rolfsii). In the molecular characterization by amplifying internal transcribed spacer (ITS) region using the ITS1 and ITS4 primer pair, the isolate TK2 showed high per cent identity of 99.35 per cent and query coverage 100 per cent with Agroathelia rolfsii in blastN search. Phylogenetic analysis of the internal transcribed spacer (ITS) and large subunit (LSU) genes played a key role in confirming the species identity. Athelia rolfsii has been reported for the first time to cause fruit rot disease on jackfruit, from Thiruvananthapuram by Sajeena et al. [1]. This study reports the infection of Agroathelia rolfsii, on jackfruit from Thrissur district. These soil-borne pathogen can spread easily and stay dormant in soil in the form of sclerotium for long time, hence it is essential to improve the management strategies and prevent its spread to other crops, for that further studies need to be conducted. This study was conducted at Department of Plant Pathology, College of Agriculture, Vellanikkara, Thrissur, Kerala between November 2023 and June 2024.