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研究了脱水对蒲葵种子活力及其膜脂过氧化的影响。结果表明:当蒲葵种子含水量下降到12%时,发芽率降至15%,含水量下降到8%时活力完全丧失,种子对脱水敏感,为顽拗型种子。在脱水过程中,种子发芽率、发芽势和发芽指数逐渐降低;膜脂过氧化程度加强,相对电导率、丙二醛(MDA)和脯氨酸的含量不断上升;超氧化物歧化酶(SOD)活性先上升,在含水量22%时出现最大值,之后急速下降;过氧化氢酶(CAT)活性随含水量的下降呈上升趋势;过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)变化趋势相同,均随着含水量的降低先上升,在含水量为17%时最高,然后逐渐下降。这些结果表明,严重脱水能降低蒲葵种子的抗氧化酶活性,并加剧膜脂过氧化,从而导致种子活力降低,甚至丧失。
The effect of dehydration on the vigor and membrane lipid peroxidation of Paphiopedra lupus was studied. The results showed that the germination rate dropped to 15% when the water content decreased to 12% and the vitality lost when the water content decreased to 8%. The seeds were sensitive to dehydration and were recalcitrant seeds. During the dehydration process, the seed germination rate, germination energy and germination index decreased gradually. The membrane lipid peroxidation degree increased, the relative conductivity, malondialdehyde (MDA) and proline content increased. The content of superoxide dismutase ) Activity first increased, and then decreased rapidly when the water content was 22%. Catalase (CAT) activity increased with the decrease of water content. The activity of peroxidase (POD) and ascorbate peroxidase APX) showed the same tendency. Both of them increased first with the decrease of water content and highest with water content of 17%, then decreased gradually. These results indicate that severe dehydration can reduce the antioxidant enzyme activity of the seeds and exacerbate membrane lipid peroxidation, resulting in reduced or even loss of seed vigor.