Genetic diversity and variability within and among populations is essential for the long-term survival and adaptive
evolution of plant species (Ge et al., 2011). Recent studies have concentrated on species biodiversity hotspots in South
America, South Africa and East Asia (Gao et al., 2014); the diversification patterns and drivers of eremophytes in arid regions
have also attracted increasing attention (Meng et al., 2015). Containing the world's largest mountains in arid regions, the
Tianshan region is located in the Eurasian hinterland and was formed by the intense collision between India and Asia during
the Cenozoic (Sun et al., 2004). In response to the geographical separation caused by various topographic conditions, droughttolerant
flora associated with the temperate continental arid climatic zone exhibits intriguing patterns of diversity. To