Abstract: Random amplified polymorphic DNA (RAPD markers) provides a powerful tool for investigation of genetic variation in natural and domesticated populations. We described genetic variations in eight Taxus chinensis var. mairei populations distributed in Shanxi province. Twenty-one arbitrary 10 base pair primers produced 134 amplification bands, 123 of which were polymorphic (91.79%). Polymorphic percentage of the eight populations was 67.16% (HDX), 67.91(FHG), 66.42% (XTH), 66.42% (MH), 50.75% (LSDX), 43.28% (YMS), 78.36% (CZBG), 50.75% (MOH), respectively. Species diversity indicated by Shannon index was 2.180, 31.7% of which was from the inter-populations, 68.3% of which was from the intra-populations. Species diversity indicated by Nei index was 0.571 and the coefficient of gene differentiation (Gst) among the populations was 0.181. The genetic distance between Hongdouxia and Mohe populations was the largest (0.55), Hongdouxia and Fenghuanggu was the smallest (0.109 2). It was concluded from the present study that there exists high genetic diversity in natural populations of T. chinensis var. mairei. Low genetic diversity is not a key factor in threatening its natural populations. The reasons that lead T. chinensis var. mairei to endangered plant are related to the destruction of habitat, innate biological, ecological characteristics and poor regeneration ability of natural populations.

Key words: Taxus chinensis var. mairei, natural population, RAPD, genetic diversity