木波罗种子脱水敏感性与膜脂过氧化的研究

刚采收的木波罗种子含水量为５８．６％。随着含水量下降，种子的发芽率和发芽指数迅速下降，种子对脱水非常敏感，是典型的顽拗性种。自然脱水时，种子胚轴和子叶中超氧物歧化酶的活性先上升，然后下降，丙二醛和脂质氢过氧化物的含量显著增加。其脱水敏感性的原因可能是当种子脱水时，植物酶ＳＯＤ的活性下降，膜脂过氧化作用加强，从而使膜的结构和功能受到破坏，种子生活力丧失。

STUDIES ON DESICCATION-SENSITIVITY AND PEROXIDATION OF MEMBRANE LIPIDS IN JACKFRUIT (ARTOCARPUS HETEROPHYLLUS LAM.) SEEDS

Experimental matcrial used was jackfruit (Artocarpus heterophgllus Lam.) seed collected in Xinyi County in Guangdong. The moisture content of newly harvested jackfruit seed was around 58.6%. As water content of seeds declined, germination percentage and germination index decreased. Jackfruit seed is very sensitive to desiccation and is defined as a typical recalcitrant seed. When seeds were naturally desiccated, the activity of superoxide dismutase (SOD) in embryonic axes and cotyledons first incresed, and then rapidly decreased. The contents of malonaldehyde (MDA) and lipid hydroperoxide rose dramatically. The reason why jackfruit Seeds were sensitive to desiccation could be that activity of SOD which is a protective enzyme in plant dropped, and that the peroxidation of membrane-lipid was accelerated. Therefore, the structure and function of membrane were damaged, and then seed viability lost.