Abstract:

In order to investigate the effects of exogenously applied 24-epibrassinolide (EBR ) on the responses of perennial ryegrass (Lolium perenne) seedling to salt stress, ‘Accent’ (salt-tolerant cultivar) and ‘Evening Shade’(salt-sensitive cultivar) were used as plant materials. The activities of antioxidant enzymes (SOD, CAT, POD, APX), the MDA, soluble sugar, proline, soluble protein and H₂O₂contents of plants under salt stress were measured. Results showed that the exogenous application of EBR promoted the salt tolerance of both cultivars by significantly reducing salt- induced damages in plants. Specifically, EBR treatment reduced the contents of MDA and ROS, whereas increased the contents of proline, soluble sugar and soluble protein, the activities of antioxidant enzymes providing better protection for plants under salinity. The effects of EBR treatment on the salt tolerance of salt sensitive cultivar ‘Evening Shade’ were more significant than salt-tolerant cultivar ‘Accent’.

Key words: 24-Epibrassinolide, Perennial ryegrass, Seedling, Salt stress, Antioxidation

摘要：

为探究24-表油菜素内酯（EBR）对多年生黑麦草（Lolium perenne）幼苗盐胁迫下的缓解作用，以较耐盐品种‘爱神特’（Accent）和盐敏感品种‘夜影’（Evening Shade）为材料，研究施用外源EBR对NaCl胁迫下黑麦草幼苗的丙二醛（MDA）、可溶性糖、脯氨酸、可溶性蛋白、过氧化氢（H₂O₂）及抗氧化酶等生理指标的影响。结果表明：盐胁迫下施用外源EBR能够显著降低幼苗的MDA含量，降低膜质过氧化水平，提高脯氨酸、可溶性糖和可溶性蛋白等渗透调节物质的含量，减少H₂O₂的积累，增加抗氧化酶活性，可有效缓解盐胁迫对幼苗所造成的伤害，且2个品种对EBR处理的敏感程度以及在不同处理时间的表现存在差异，对盐敏感品种夜影的缓解效果更明显，且前期处理效果更佳。

关键词: 24-表油菜素内酯, 多年生黑麦草, 幼苗, 盐胁迫, 抗氧化