Abstract
Taxus globosa is a conifer native to the Nearctic region, inhabiting isolated mountainous areas of Mexico’s Sierra Madre Oriental. Its limited distribution and fragmented habitats raise concerns about its genetic diversity. To address this, we assessed genetic diversity and structure across six populations ranging from Nuevo León to Oaxaca using microsatellite markers and methods such as analysis of molecular variance (AMOVA) and Bayesian assignment analysis. The results indicated significant genetic structuring and reduced genetic diversity from north to south, with low observed heterozygosity (Ho = 0.18 ± 0.03) and high inbreeding levels (Fis = 0.75 ± 0.04). Four main genetic groups were identified, and the Hidalgo population showed significant differentiation. All populations demonstrated evidence of recent reductions, especially in Veracruz and Oaxaca, likely due to silvicultural activities. These findings highlight the need for conservation strategies to protect T. globosa’s genetic diversity and suggest that ex situ cultivation practices should be implemented for future reforestation efforts.