Molecular Detection and Characterization of Carrot Motley Dwarf Virus Complex in Carrot Production Fields

Abstract

Carrot is an economically important vegetable crop cultivated extensively for its nutritional and commercial value; however, viral diseases pose a major constraint to its productivity and quality. Among these, the Carrot Motley Dwarf Virus (CMDV) complex is recognized as a serious pathogen causing symptoms such as leaf reddening, yellowing, stunted growth, and root deformation, ultimately leading to substantial yield losses. The present study was conducted to detect and characterize the Carrot Motley Dwarf Virus complex in carrot production fields using molecular diagnostic approaches. Field surveys were carried out in major carrot-growing regions, and symptomatic as well as asymptomatic plant samples were collected for analysis. Total RNA was extracted from collected samples and subjected to reverse transcription polymerase chain reaction (RT-PCR) using virus-specific primers targeting conserved genomic regions associated with the CMDV complex. Amplified products were sequenced and analyzed using BLAST and phylogenetic tools to determine the genetic relationship among detected viral isolates and previously reported strains. The results confirmed the presence of the Carrot Motley Dwarf Virus complex in symptomatic carrot plants, while healthy samples showed negative amplification. Sequence analysis revealed high nucleotide similarity with known isolates of viruses associated with the CMDV complex, confirming their molecular identity. Phylogenetic analysis demonstrated genetic diversity among the detected isolates and indicated close evolutionary relationships with international reference strains. The occurrence of mixed viral infections was also observed in several field samples, suggesting a complex epidemiological pattern in carrot production systems. This study provides important insights into the molecular diversity and distribution of the CMDV complex in carrot fields and highlights the significance of early diagnosis for effective disease management. The findings contribute to the development of improved surveillance programs and integrated disease management strategies aimed at minimizing economic losses in carrot cultivation.