【作者】 毛培春；

【导师】 云锦凤； 米福贵；

【作者基本信息】 内蒙古农业大学 ， 草业科学， 2004， 硕士

【摘要】 本文采用模拟盐胁迫对6属18种禾本科牧草种子萌发期和幼苗期的耐盐性进行比较研究。结果表明：(1)种子萌发期各禾草的发芽率、发芽势、简化活力指数、发芽指数、耐盐指数等生理指标在低盐浓度(0.2％和0.4％)时与对照相比较出现上升趋势，随着盐胁迫浓度的增加而逐渐下降；胚根／胚芽比在低盐浓度时有下降趋势，随浓度增加而呈上升趋势。说明低盐浓度可刺激种子萌发，但在较高盐浓度胁迫下种子活力下降，下降程度的差异说明各禾草耐盐性不同。(2)随着盐胁迫浓度的增加，各禾草幼苗期的游离脯氨酸和细胞膜透性与对照相比较有逐渐上升趋势，低盐浓度(0.3％和0.6％)时上升不显著，随着盐浓度的增加，上升趋势出现显著变化，表明各禾草的幼苗在盐浓度低于0.6％时对盐胁迫的敏感性差别不大；而叶片含水量出现逐渐下降趋势，在盐浓度大于0.9％时下降较显著，变化的程度因禾草耐盐性不同而异。(3)盐胁迫下各禾草的生理指标变化幅度因品种而异，根据变化幅度的差异可总结出各禾草的耐盐性大小。 通过各生理指标综合评价和耐盐性排序得到各禾草种子萌发期和幼苗期耐盐性大小和综合排序。更多还原

【Abstract】 The difference of salt-endurance at stages of seed germination and seedling was studied on 18 grasses through simulating salt stress. The results shown that: (1) Physiological index, such as relative germination percentage, relative germination potential, vigor index, germination index and salt-tolerance index at seed germanous of 18 grass were increased at low degree stress within 0.2-0.4% salt concentration, and were decreased when salt concentration was increasing, while radicle/embryo ratio had opposite changing. It indicated that low salt stress can promote the germination of seed, but high salt stress resulted in decreasing of seed vitality. The descent degrees have relation to different grasses. (2) At stage of seedling, Physiological index, such as the content of free Proline and cell membrane penetration were increased with the increasing salt concentration. Under the low salt concentration (0.3% or 0.6%) the increasing trend is unmarked, with the salt concentration increasing, the increasing trend became marked, which showed that the sensitivity of grasses to low salt stress (below 0.6%) is approach; and relative water content of leaves decrease with the increasing of salt concentration, and the decreasing trend became marked with high salt stress (0.9%), the changing degree have relation to the salt tolerance of grasses. (3) Under salt stress the changing range of different physiologic indexes have relation to different grasses, then the salt-tolerance of different grasses can be evaluated through the changing range of different physiologic indexes was evaluated under salt stress.By means of the physiologic indexes is evaluated synthetically and arranged ordering can obtain of seed germination and seedling respectively, and can obtain salt-tolerance and salt-tolerance ordering of all kinds grasses finally.更多还原