Abstract: In this study,20 Sorghum bicolor×Sudanense germplasm resources were used as materials and treated with 25 mg·L^-1 Cd solution. The morphological and physiological indexes of Sorghum bicolor×Sudanense at seedling stage were determined to provide reference and theoretical basis for the selection of cadmium-tolerant germplasm resources and the breeding of new varieties. The results showed that there were different degrees of differences in 13 indexes between the control group and the treatment groups. Among them,plant height,stem diameter,chlorophyll content,maximum photosynthetic efficiency,health index and root activity of different germplasm resources of grasses decreased to different degrees,ranging from 12% to 99%,and the root shoot ratio decreased from 70% to 90%. The relative electrical conductivity and MDA content of all varieties increased to different degrees,and the relative electrical conductivity increased from 2% to 65%,and the MDA increased degree varied greatly. According to the membership function and cluster analysis,20 samples were divided into 4 groups by D value:2 samples of high cadmium tolerance,5 samples of medium cadmium tolerance,10 samples of low cadmium tolerance and 3 samples of cadmium sensitive.

Key words: Sorghum bicolor×Sudanense, Cadmium stress, Seedling stage, Comprehensive evaluation

摘要： 本研究以20份高丹草(Sorghum bicolor×Sudanense)种质资源为材料，以25 mg·L^-1 Cd溶液进行胁迫处理，通过测定高丹草苗期的形态和生理指标进行综合评价，以期为高丹草耐镉种质资源筛选以及新品种选育提供参考和理论依据。结果表明，20份高丹草对照组和处理组的13个指标间存在着不同程度的差异。其中，不同高丹草种质资源的株高、茎粗、叶绿素含量、最大光合效率、健康指数、根系活力等均出现不同程度下降，下降程度从12%~99%不等，根冠比从下降70%到上升90%不等；各品种的相对电导率和丙二醛含量均出现不同程度上升，其中，相对电导率上升程度从2%到65%不等，丙二醛上升程度差异巨大。采用隶属函数和聚类分析，将20份高丹草依据D值分为4类：高耐镉型2份、中耐镉型5份、低耐镉型10份和镉敏感型3份。

关键词: 高丹草, 镉胁迫, 幼苗期, 综合评价