Occurrence of Gilbertella persicaria causing soft rot of papaya in India

Carica papaya is a tropical fruit with immense health benefits and commercial importance. It is grown widely all over tropics and sub-tropics. Post-harvest pathogens are emerging as a major threat in the marketing and processing of papaya fruits. Soft rot symptom was beforehand established to be caused by fungal pathogen Rhizopus spp. The incidence of Gilbertella persicaria in papaya, producing similar symptoms have been identified in the fruits collected from college orchard of Tamil Nadu Agricultural University. Recently the fungus has being reported as causal organism of rot disease in papaya in few other countries. The responsible pathogen was identified as G. persicaria based on isolation, purification and further analysis. Morphological and molecular characterization was performed for pathogen identification. Molecular characterization was carried out using Internal Transcribed Spacer (ITS) region and Actin (Gil ACT) gene and phylogenetic analysis was done with concatenated sequence alignment in MEGA 11. Pathogenicity test was done using fresh papaya fruits to establish the pathogenic nature of the fungus and there by proved the Koch's postulate.