幼苗是一年生植物生活周期中最脆弱的阶段，它决定着植物个体的生存和种群繁衍。能在逆境下生存的植物，必然具有其成功的苗期适应对策。而对此进行探索将对我们深入理解植物整个生长周期应对逆境的独特策略具有重要意义。然而目前对植物苗期耐盐机制特别是极端环境幼苗的生存基础研究很有限。异子蓬是分布于新疆极端盐渍荒漠的一年生盐生植物，调查发现其幼苗在高盐（伴随其他胁迫）生境中有着显著迟滞发育的表型特征，这与其幼苗对恶劣生境的适应密切相关。鉴于此，本项目基于前期研究基础，拟通过发育中细胞/亚细胞结构观察；光合、抗氧化、渗调系统及激素水平关键指标测定；相关基因应答的cDNA-AFLP及双向电泳技术分析等方面，开展盐胁迫下异子蓬幼苗迟滞发育的内在结构基础、生理生化响应、相关基因不同水平应答三个不同层面的研究，期望初步阐明一年生盐生植物异子蓬幼苗迟滞发育机制及其与耐盐（逆）的相关性，并为新疆盐碱地改良提供理论依据。

The seedling stage is the most fragile and vulnerable stage in life cycle of the annual plant, it may determine the survival of individuals and reproduction and thriving of the populations. Plant species which can survive adverse circumstances must have developed successful adaptation strategies in seedling stage. To explore the mechanism of seedling survival of adversity is of great significance for us to understand the unique strategy of plant to stress environment in the whole life cycle. However, so far, the understanding to mechanism of salt tolerance of seedling, especially the survival strategy of seedling in extremely adverse habitats, is far from enough. Suaeda aralocaspica is an annual halophyte distributed in extremely saline environment in Xinjiang desert, we found in field investigation that its seedling presented a phenotype of significantly developmental delay in high salinity (concomitant with other stresses) environment, this characteristic is closely related to the adaptability of the seedling to harsh habitat. So, in the present project, based on our previous investigation we plan to study on phenomenon of seedling developmental delay of S. aralocaspica at three different aspects as: inner micro-structure basis, physiological and biochemical responses, and different expression levels of relevant genes under salt stress, by observation of cellular/subcellular structure in seedling development; assay of the key parameters on photosynthesis, antioxidant system, osmosis regulation system, and phyto-hormone; analysis of gene response by cDNA-AFLP and 2-D gel electrophoresis techniques. With these work we expect to gain an insight into the mechanism of seedling developmental delay of the annual halophyte- S. aralocaspica, and its correlation with salt (adverse) tolerance, and finally provide theoretical evidence for improvement of saline-alkaline land in Xinjiang.