Diversity and Distribution of Cucumber Mosaic Virus Strains Infecting Pepper and Cucurbit Crops

Abstract

Cucumber mosaic virus (CMV) is one of the most widespread and economically important plant viruses affecting a wide range of horticultural crops, including pepper and cucurbits. The present study investigated the diversity and distribution of CMV strains infecting pepper and cucurbit crops across major cultivation regions. Field surveys were conducted to collect symptomatic plant samples exhibiting mosaic, chlorosis, leaf distortion, and stunted growth. Viral infection was initially confirmed using serological assays, followed by molecular characterization through reverse transcription PCR (RT-PCR) targeting conserved genomic regions. Sequencing and phylogenetic analysis were performed to determine strain variability and evolutionary relationships among CMV isolates. The results revealed significant genetic diversity among CMV isolates collected from pepper and cucurbit hosts, indicating the coexistence of multiple strains within the same agroecosystems. Phylogenetic clustering demonstrated host-associated and region-specific grouping patterns, suggesting both localized evolution and cross-host transmission. Certain strains showed closer genetic relationships despite being isolated from different host species, highlighting the role of mixed cropping systems and vector-mediated spread in virus dissemination. Differences in strain distribution were observed across geographical locations, reflecting environmental influences and agricultural practices. The study confirms the wide adaptability and high genetic variability of CMV populations infecting solanaceous and cucurbit crops. These findings provide important insights into the epidemiology, evolution, and spread of CMV and emphasize the need for continuous monitoring and integrated virus management strategies, including the use of virus-free planting material and vector control measures.