Abstract: To investigate the strength of UV-B radiation resistance of Elymus nutansand to screen out excellent germplasm materials,9 wild Elymus nutans from different regions of China were used to study their growth and developmental characteristics and physiological properties under UV-B radiation at the seedling stage,and the UV-B radiation resistance of Elymus nutanswas comprehensively evaluated using the subordinate function method. The results showed that the growth and physiological properties of 9 materials were affected to varying degrees as the level of UV-B radiation increased. The materials could be classified into strong,medium,and weak UV-B resistant materials. The strong resistant material was QH009,which was the least affected by UV-B radiation,with the lowest leaf damage,the smallest decrease of relative water content,the smallest increase of cell membrane system indicators,the largest accumulation of osmoregulatory substances,significantly higher enzyme activity of antioxidant system than the rest of the materials(P<0.05),the largest accumulation of secondary metabolites,and the smallest decrease of photosynthetic system indicators,and can be used as the basic material for the selection and utilization of new varieties of Elymus nutans.

Key words: Elymus nutans, UV-B radiation, Comprehensive evaluation

摘要： 为探究垂穗披碱草(Elymus nutans)抗UV-B辐射能力强弱，筛选出优异种质材料，本研究以9份来自我国不同地区的野生垂穗披碱草为对象，研究其苗期UV-B辐射下的生长特性与生理特性，对其抗UV-B辐射能力进行综合评价。结果表明：随着UV-B辐射程度的加剧，9份材料的生长特性与生理特性均不同程度地受到影响。可将9份材料分为强、中、弱抗UV-B辐射材料。强抗材料为QH009，该材料受UV-B辐射影响最小，叶片受损程度最低，相对含水量下降幅度最小，细胞膜系统指标上升幅度最小，渗透调节物质积累最多，抗氧化系统酶活性显著高于其余材料(P<0.05)，次生代谢物积累最多，光合系统指标下降幅度最小，可作为垂穗披碱草新品种选育与利用的基础材料。

关键词: 垂穗披碱草, UV-B辐射, 综合评价