The Middle East as a global hub for the dissemination of tobacco mild green mosaic virus: Insights from phylogeographic reconstruction

Tobacco mild green mosaic virus (TMGMV) is a globally distributed tobamovirus that poses a significant threat to solanaceous crops; however, the temporal dynamics underlying its emergence remain largely uncharacterized. In this study, the MASCOT-Skyline structured coalescent framework was utilized to reconstruct the evolutionary history of TMGMV. The mean substitution rate for the coat protein gene was estimated at 3.89 × 10 − 4 substitutions/site/year (95% credibility interval 2.17 × 10 − 4 – 5.71 × 10 − 4 ). The origin of the current population was traced to the Middle East around the year 1876. Bayesian phylogeographic reconstruction identified the Middle East as the most likely spatial origin of TMGMV (RSPP = 0.86), revealing its role as a primary hub that seeded migrations into Asia (1949–2012), Europe (1962–1999), and the Americas (1982–2018). Demographic history analysis indicated that TMGMV populations have remained largely stable over time across their global range, with only minor regional fluctuations. Overall, these findings provide critical insights into the complex spatio-temporal dynamics of TMGMV and highlight the pivotal role of the Middle East in the global dissemination of this pathogen.