摘要
以黄瓜种子为材料,研究了在人工加速老化的条件下(40℃,rH93％),种子活力与脂质过氧化及内源多胺的关系。结果表明:随着老化天数的增加,种子活力显著下降,种子的氢过氧化物和丙二醛含量增加;超氧物歧化酶和过氧化氢酶活性降低;细胞膜透性增大,种子浸泡液的电导率和K^+、Na^+、Ca^(2+)漏失量相应增加,而且K^+是被测离子中最敏感的离子。同时,内源精胺、亚精胺含量降低,而腐胺含量逐渐增加。本文认为脂质过氧化作用的加强是导致种子老化劣变的主要原因;内源多胺水平的变化与种子老化劣变亦有着密切的关系。
The relationship between the lipid peroxidation , endogenous polyamine level and seed vigour was studied during the accelerated aging under the condition of 40℃ , 93% relative humidity in cucumber (CV. cucumis sativas L. ) seeds. The results showed that with the extension of period of aging time (0,3,5,7,10 days), the seed vigour rapidly declined, and the permeability of cell membeane increased in terms of the electroconductivity and the level of the ions of potassium, sodium and calcium in the steeped water. Potassium ion was most sensitive to aging among the tested ions. The level of hydropreoxide and malondialdehyde (MDA) increased also during aging, which are peroxidative products of lipids. However, the superoxide dismutase (SOD) and catalase activity declined with increase of aging time. These results strongly supported the idea that the peroxidation of lipids induced by active oxygen resultsd in the damage of membrane system, the decline of emzyme activities and the dixorder of cellular metabolism by the attack of free radicals and by the toxicity of the secondary products of lipid peroxidation. In addition, it was discovered that there was a close relation of endogenous polyamine level to seed vigour. During aging the level of endogenous polyamine level to seed vigour. During aging the level of endogenous spermine and sper-midine declined with the increase of aging time, whereas a large number of the endogenous pu-trescine was accumulated. The decline of the endogenous polyamine level (spermine and spermi-dine) might be disadvantagous to stability of the structure of the membrane and chromosome etc.
基金
浙江省自然科学基金
关键词
过氧化脂质
多胺
黄瓜
种子
cucumber seed
lipid peroxidation, polyamines
seed vigour
seed aging
