适应是生物对外界环境变化的响应。识别适应过程中的遗传变异及分子机制是进化生物学的重要研究内容。大量野生植物对恶劣生境具有极强适应性，可能进化出了独特和高效的逆境适应策略。本项目以东阿拉善-西鄂尔多斯地区特有泌盐植物长叶红砂为研究对象，以研究其逆境适应机制为目的，借助RAD-seq技术获取SNP数据，开展种群基因组学研究，在明晰其种群遗传结构的基础上，充分考虑异质生境对不同种群适应性的影响，从种群、亚种群及物种层面识别生境适应遗传变异及关联基因，通过基因表达特性分析及植物转化技术系统鉴定SNP变异对特定基因功能、代谢通路、细胞过程等的影响，阐释它们与不同种群适合度的相关性，揭示它们在逆境适应中的分子基础。项目的实施将有望挖掘出长叶红砂适应逆境的特有元件，在其逆境适应分子机制研究上取得突破，为挖掘其优质抗逆遗传资源开辟新思路，为了解该区域特有种质资源的避难、演化及适应机制积累科学依据。

Adaptation is the response of a species to environmental change. Identifying the genetic variation and their molecular mechanism in the process of adaptation is the core content in evolution biology. Numerous wild plant species exhibit strong adaptability to extreme environment, and has probably evolved distinct and efficient adaption strategies response to the adverse environment. Reaumuria trigyna is an endangered dicotyledonous shrub with the features of a recretohalophyte. This species is endemic to the Eastern Alxa–Western Ordos area, a salinized desert in Inner Mongolia. To study the adaptive mechanisms allowing it to tolerate the stress imposed by the adverse habitats, we identify single nucleotide polymorphism (SNP) data by using restriction-site associated DNA sequencing (RAD-seq) technology, and perform population genomics study on R. trigyna. Following population genetic structure analysis, and fully considering the influence of heterogeneous habitats on the adaptability of different populations, we would identify SNPs that representing adaptive genetic variations on the levels of population, subpopulation and the whole species, and locate these loci on the genes of R. trigyna transcriptomic data. Finally, through gene expression profiling analysis and plant transforming experiments, we will systematically study the influence of the variation on gene function, metabolic pathway and cellular process, and elaborate the correlation between the genetic variation and the population fitness. The study will prompt studies on the molecular mechanisms of adaptive evolution, and provide insight into the discovery of unique adaption elements in R. trigyna. The results of this study can also further extend the knowledge on the environment adaption, refuge and evolution of the germplasm resources that survive in Ordos area.