Abstract: In order to study the adaptability of Sorghum sudanense to salt stress， 10 varieties of Sorghum sudanense with different salt tolerance grades were used as materials and treated with different concentrations of NaCl solution at the germination stage to study the morphological indexes physiological characteristics， and leaf anatomical structure changes. The results showed that salt stress had a significant effect on the morphological indexes of S. sudanense， especially under high salt concentration. In addition， salt stress could significantly increase the contents of malondialdehyde， proline and soluble protein in S. sudanense leaves. With the increase of salt concentration， the activities of peroxidase and superoxide dismutase in salt-tolerant materials continued to increase， while the activities of the two enzymes in salt-sensitive materials increased first and then decreased. Salt stress significantly increased the thickness of midvein， thickness of vascular bundle， thickness of bulliform cells and thickness of lower epidermal cell of high-sensitivity S. sudanense leaves， and significantly decreased the thickness of midvein， thickness of leaf and thickness of vascular bundle of high-sensitivity S. sudanense leaves. Principal component analysis （PCA） was used to screen proline， thickness of vascular bundle， thickness of leaf and thickness of upper epidermal cell as the key indexes for salt tolerance screening of S. sudanense.

Key words: Sorghum sudanense, Salt stress, Physiological characteristics, Anatomical structure

摘要： 为研究苏丹草（Sorghum sudanense）对盐胁迫的适应性变化，本研究以10份不同耐盐级别的苏丹草为材料，于萌芽期用不同浓度NaCl溶液进行胁迫处理，研究不同耐盐级别的苏丹草材料在盐胁迫下形态、生理特征及叶片解剖结构的变化规律。结果表明：盐胁迫对苏丹草的形态指标造成显著影响，尤其在高盐浓度下；盐胁迫能显著提高苏丹草叶片的丙二醛、脯氨酸、可溶性蛋白含量；随着盐浓度的提升，耐盐材料的过氧化物酶和超氧化物歧化酶活性持续上升，然而敏盐材料的两种酶活性则呈现先升后降的变化模式；盐胁迫显著增加了高耐苏丹草材料叶片的中脉厚度、维管束直径、泡状细胞厚度及下表皮细胞厚度，显著降低了高敏苏丹草材料叶片的中脉厚度、叶片厚度、维管束直径等。主成分分析结果表明，脯氨酸含量、维管束直径、叶片厚度、上表皮细胞厚度等可作为苏丹草耐盐性筛选的关键指标。

关键词: 苏丹草, 盐胁迫, 生理特征, 解剖结构