摘要
黄皮种子对脱水非常敏感,含水量从51％下降至22.4％,种子的发芽率和发芽指数为零,是典型的顽拗性种子。自然脱水时,种子中可溶性糖的含量增加,淀粉的含量下降;磷酸化酶,异柠檬酸裂解酶以及旺轴中α—和β—淀粉酶的活性先增加然后下降;子叶中α—和β—淀粉酶的活性呈下降趋势。这些变化类似于吸水萌发的黄皮和豌豆种子。可以认为黄皮种子脱水敏感性的原因是在脱落时萌发。随着萌发过程的进行,水分成为限制因子,使种子生活力丧失。
Chinese Wampee seed which is very sensitive to desiccation is a typical recalcitrant seed. Initially, the mean moisture contents of seeds were about 51% (wmb). The viability and germination index of seeds were lost completely when moisture content decreased to 22. 4%. As seeds dry naturally, the content of soluble sugar in seeds increased and the content of starch in seeds decreased. In the meantime, the activities of phosphorylase and isocitrate lyase in seeds, and that of α-and β-amylase in embryonic axes rose initially, and then declined. These changes were very similar to those occured in the germinating seeds of Chinese Wampee and pea. It is considered that the reason why Chinese Wampee seeds are sensitive to desiccation might be that the seeds germinate at their shedding. As these germinationrelated events proceed, the seeds become increasingly sensitive to desiccation, water becomes a limiting factor and the viability of seeds is lost.
基金
国家自然科学基金
联合国国际植物遗传资源委员会(IBPGR)资助项目
