Serological and molecular characterization of Cucumber Mosaic Virus (CMV) infecting cucumber (Cucumis sativus L.) in southern Tamil Nadu

Cucumber Mosaic Virus (CMV) is a significant threat to cucumber (Cucumis sativus L.) cultivation, causing mosaic patterns, leaf crinkling, fruit distortion and stunting. This study investigates the serological and molecular characteristics of a CMV- Anantha nambi Nambi kuruchi isolate (CMV-ANK) collected from cucumber plants in major growing areas of Tamil Nadu. Host range studies revealed that CMV-ANK caused systemic infection in multiple crops and chlorotic lesions in okra, chenopodium and wild cucumber. The virus was confirmed using Triple Antibody Sandwich Enzyme-Linked Immunosorbent Assay (TAS-ELISA) and Reverse transcription polymerase chain reaction (RT-PCR) with Coat Protein (CP) gene-specific primers, producing a 1200 bp amplicon. Nucleotide sequencing demonstrated that 99.85 % identity with a CMV isolate from tomato (MZ298672), indicating close genetic similarity. Phylogenetic analysis showed that CMV-ANK clusters with other CMV isolates affecting various crops. Physical property analysis revealed a dilution endpoint at 10-5, thermal inactivation at 65 °C and longevity in vitro up to three days at room temperature and five days under refrigeration. Seed transmission studies confirmed an 83.33 % transmission rate through seeds from infected plants, reinforcing the risk of seed-borne spread. These findings underscore the adaptability and resilience of CMV-ANK, highlighting the need for effective disease management strategies, including the development of resistant cucumber varieties and integrated pest management. The insights gained from this study contribute to understanding CMV epidemiology and offer a foundation for future research aimed at controlling its impact on cucumber production.