Isolation, Biological Purification, and Serological Detection of a Tobamovirus from the Medicinal Plant Physalis alkekengi using Polyclonal Antibodies and Dot-ELISA

Viral infections of medicinal plants represent a significant threat to the quality and yield of bioactive compounds. Physalis alkekengi, a species of the Solanaceae family widely used in traditional medicine, is susceptible to viral diseases that impair its therapeutic value. This study isolates, biologically purifies, and immunodiagnostically characterizes a tobamovirus infecting P. alkekengi. Virus isolates were obtained by mechanical inoculation of Nicotiana sylvestris with sap from symptomatic leaves. Biological purification was performed using local lesion isolation on Nicotiana glutinosa. The purified virus, designated Ph TMV, was characterized by host range studies, electron microscopy, and serological methods. Polyclonal antibodies were raised in rabbits, and a dot-ELISA assay was developed for rapid detection. The virus showed typical tobamovirus morphology with rod-shaped particles approximately 300 nm in length. The obtained polyclonal antibodies reached a titer of 1:256. Host range studies demonstrated systemic mosaic symptoms on N. tabacum cv. Samsun and local necrotic lesions on N. glutinosa. The isolated strain was deposited in the National Collection of Phytopathogenic Microorganisms (WDCM #862). These results contribute to the understanding of viral pathogens affecting P. alkekengi and provide a basis for future development of diagnostic tools and virus management strategies.