Complete-genome characterisation of tobacco mosaic virus isolate 30102 from naturally infected wild Nicotiana glauca in Egypt

Abstract

Abstract Tobacco mosaic virus (TMV) is a stable, mechanically transmitted Tobamovirus infecting solanaceous hosts, but complete-genome data from naturally infected wild hosts in Egypt remain limited. Symptomatic wild tree tobacco, Nicotiana glauca Graham, was collected from New Borg El-Arab, Alexandria Governorate, Egypt, and examined for TMV infection. Among 29 symptomatic samples screened by DAS-ELISA, two samples, S10 and S24, were positive. Both were confirmed by RT-PCR using movement protein-specific primers, which amplified the expected 422-bp fragment. Sample S10 was selected for single-lesion purification and complete-genome sequencing, and the resulting isolate was designated TMV isolate 30102. Biological indexing confirmed infectivity, and transmission electron microscopy revealed rigid rod-shaped particles approximately 300 nm long. The complete 6,395-nt genome was assembled from seven overlapping RT-PCR fragments and deposited as ON142174.1. Sequence identity and maximum-likelihood phylogeny placed ON142174.1 within the globally distributed TMV population.