基于叶片特征的18种盐生植物耐盐性综合评价 postprint

Abstract: Soil salinization is a critical barrier to ecological restoration and sustainable development in the arid regions of Northwest China. To screen for plant resources suitable for greening saline-alkali lands in this area and then evaluate their efficacy, this study focused on 18 halophyte species from the Karamay Halophyte Botanic Garden, and considered Xanthoceras sorbifolium as a control. Twenty physiological and biochemical indicators were systematically measured under salt stress, including leaf water content, leaf thickness, chlorophyll content, antioxidant enzyme activities, and chlorophyll fluorescence parameters. A comprehensive salt tolerance evaluation system based on leaf traits was constructed using principal component analysis (PCA) and the membership function method. The results showed significant differences in salt tolerance among the 19 species, with comprehensive evaluation values (D- values) ranging from 0.20 to 0.67. Among the plants tested, Caragana sinica and Suaeda salsa demonstrated the strongest salt tolerance (D=0.67), whereas Xanthoceras sorbifolium was the most sensitive (D=0.20). PCA revealed that photosynthetic fluorescence parameters and the antioxidant enzyme system are core indicators that reflect plant salt tolerance. This evaluation system is objective and accurate; the identified superior halophytes provide important germplasm resources and have a scientific basis for vegetation restoration, ecological rehabilitation, and landscaping in saline-alkali land of the arid regions of northwest China.