【作者】 李玉荣；

【导师】 韩建国；

【作者基本信息】 中国农业大学 ， 草业科学， 2004， 硕士

【摘要】 试验以新麦草和蓝茎冰草种子为研究对象，对自然和人工加速老化的新麦草和蓝茎冰草种子中发生的生理生化变化进行了研究。通过上述研究，探讨了种子劣变的机理，探索了新麦草和蓝茎冰草种子的活力测定方法，为种质资源的保存和生产用种的贮藏提供理论指导。结果表明： 随着种子老化，种子的发芽率、发芽势降低。老化初期有一持续期，发芽率降低的速度很慢，持续期过后是急速下降期。在发芽率持续期内，发芽率变化不大，但种子内部发生了大量的生化变化，种子的发芽指数、活力指数和酸性磷酸酯酶活性先于发芽率发生变化，是评定新麦草和蓝茎冰草种子质量的很好指标。 通过测定种子浸出液的电导率和可溶性糖的结果表明，新麦草和蓝茎冰草种子的电导率与种子劣变程度不成正比例关系，因而电导率不适合作为评价新麦草和蓝茎冰草种子质量的指标；可溶性糖泄露在新麦草和蓝茎冰草种子中表现出相反的变化趋势。因此，可溶性糖泄露与种子活力没有确定的关系。 种子老化过程中，可溶性蛋白质、游离氨基酸、脱氢酶及酸性磷酸酯酶活性显著变化，说明种子的老化使种子的代谢系统受到破坏。 对种子的脂质过氧化产物之一丙二醛的测定表明，新麦草和蓝茎冰草种子劣变过程中，丙二醛的含量显著低于对照，因而脂质过氧化在新麦草和蓝茎冰草种子劣变过程中未必起作用。 自然老化与人工加速老化对新麦草和蓝茎冰草种子生理生化的影响基本一致，因而用人工加速老化可很好的预测种子的耐贮性。更多还原

【Abstract】 A study on deterioration in Russian wildryegrass and Rosana western wheatgrass seeds was conducted to analyze some of the physiological and biochemical changes produced under natural and accelerated ageing conditions. Understanding these changes involved in this process would enable the selection of a better vigor test for the evalvation of seed quality in Russian wildryegrass and Rosana western wheatgrass seeds. The research probed into the mechanism of seed deterioration. This will help to supply instruction for the preservation of germ plasm and storage of seeds.The results indicated that the germination rate and Germination energy declined as seed ageing. At first, germination percentage decreased slowly, but occured a series of biochemical changes, germination index, vigor index and acid phosphoesterase activity of changes significantly. Thereafter, germination rate droped dramatically. Germination index,vigor index and acid phosphoesterase activity of tests provided better parameters in assessing seed quality of Russian wildryegrass and Rosana western wheatgrass seeds .The conductance of leachate was poorly correlated with viability, so it not to be a good index for seed deterioration. Leaching of sugar showed two diverse tendencies in Russian wildryegrass and Rosana western wheatgrass seeds. So there is not a determinate relateship between soluble sugar and vigor.The contents of amino acids, soluble protein changed. A decreased activity of dehydrogenase and acid phosphoesterase was noticed during ageing. It shows that metabolic system was destrctived in ageing seeds.The content of malondialdehyde significantly decreased during aging. It is suggested that lipid peroxidation in seeds may not play an important role in the seed deterioration.The processes of deterioration under accelerated ageing conditions are similar to those under natural conditions. So the accelerated ageing can be used to predict storageabiliy of seeds.更多还原