西洋参种胚形态后熟过程中种子内源激素变化动态及其对种胚发育的调节

Dynamics of endogenous hormone in American ginseng seed during morphological after-ripening period and their regulation to embryo development

目的 阐述西洋参种胚形态后熟过程中内源激素与种胚发育的关系。方法 激素测试用 HPL C法 ,外标法定量 ,激素含量以 ng/ gfw表示 ;淀粉酶总活性测定用比色法 ,比色波长为 5 2 0 nm。结果 在西洋参种胚形态后熟过程中吲哚乙酸 (IAA)出现两次高峰 ,第一次峰值出现在层积开始后第 80天 ,第二次峰值出现在层积后第 140天 ,随后很快下降。赤霉素 (GA3)在层积处理开始的第 6 0天有一个高峰 ,至第 12 0天以后又开始持续升高。玉米素(Z)的变化动态与 GA3相似。脱落酸 (ABA)的变化动态与内源 IAA的变化动态相似 ,不同之处是在层积开始后的前 2 0 d一直没有检测到 ABA的存在。结论 GA3和 Z是西洋参种子萌发促进因子 ,而不能启动原胚的起始发育。ABA第一个高峰的出现可能正是引起西洋参种胚起始发育的因子 ,第二个高峰则与种胚的快速发育一致 。

Object To aquire a deeper understanding of the relationship between endogenous hormone and embryo development of the seed of Panax quinquefolius L Methods The content of endogenous hormone was determined by HPLC with the use of external standard and expressed in term of ng/gfw Total amylase activity was assessed by spectrophotometry at λ 520 nm Results During the after ripening period of American ginseng embryo, peak concentrations of indole acetic acid (IAA) appeared twice, one on the 80th day and the other on the 140th day after stratification, and declined quickly thereafter Abscisic acid (ABA) showed similar dynamics, except that it was undetectable during the first 20 d after stratification gibberellic acid (GA 3) and zeatin (Z) also showed 2 peaks, which appeared on the 60th and 120th day, respectively Conclusion GA 3 and Z can promote germination of American ginseng seed, but cannot ignite the development of proembryo Probably the first peak of ABA was the factor for the ignition of embryo development, and the second peak runs in coincidence with the rapid development of the embryo and may inhibit the viviparity of American ginseng seed