黄皮种子发育过程中脱水敏感性与细胞膜透性的关系

黄皮（Ｃｌａｕｓｅｎａ ｌａｎｓｉｕｍ （Ｌｏｕｒ．） Ｓｋｅｅｌｓ）胚轴与完整种子的发育模式以及发育中电解质渗漏率变化有些不同． 种子生理成熟前、后的胚轴对脱水的反应也不同，前者经轻微脱水可提高萌发率和活力指数，后者不耐任何程度的脱水．活力指数的急剧下降伴随着电解质渗漏率的迅速上升．实验表明，黄皮种子在发育过程中没有形成耐脱水性． 细胞膜透性变化可反映脱水对种子的伤害程度

RELATION BETWEEN DESICCATION SENSITIVITY AND MEMBRANE PERMEABILITY OF DEVELOPING CLAUSENA LANSIUM SEEDS

Desiccation sensitivity and its relation to membrane permeability of the embryonic axes of the developing wampee (Clausena lansium (Lour.) Skeels) seeds were studied by measuring the changes in electrolyte leakage, germination and vigor index after the embryonic axes were rapidly air dried to various water contents. During development, the fresh and dry weight per seed reached nearly maximum value at 72 d after anthesis, but the dry weight per embryonic axis continuously increased until 85 d after anthesis. The embryonic axes acquired the full capacity for germination at 58 d after anthesis and their vigor index continuously rose up from 51 to 92 d after anthesis. The electrolyte leakage of the developing the embryonic axes linearly declined to the minimum value at 72 d after anthesis and then went up again. The electrolyte leakage of the embryonic axes was higher than that of the whole seeds at the same time. The immature embryonic axes did not germinate completely, while mild desiccation could improve their viability. Any degree of desiccation decreased the vigor index of the embryonic axes which have reached physiological maturation and the decline of vigor index was corresponded to the increase of electrolyte leakage. According to this experiment, the authors concluded that wampee seeds did not gain desiccation tolerance which was a characteristic of orthodox seeds during development. High water content was essential for maintaining membrane integrity and stabiligy of matured wampee seeds. The injury of seed viability during dehydration could be estimated by using the electro conductivity method.