野生杏种子对外源赤霉素的生理响应

Physiological Response of Wild Apricot Seeds to Exogenous Gibberellin

以甜杏仁和苦杏仁天山野生杏种子为对象,观察赤霉素处理对种子打破休眠的影响、淀粉含量的动态变化、可溶性糖含量以及淀粉酶活性等生理指标。结果表明:赤霉素可以提高天山野杏的发芽率,其中对甜杏仁的作用更显著。种子吸水之后子叶中可溶性糖含量增高,其中苦杏仁的增幅大于甜杏仁,萌发之后2种杏仁可溶性糖含量均迅速下降。野杏干种子有较高的α-和β-淀粉酶活性,萌发种子中α-淀粉酶的活性比未萌发的种子活性高。可溶性糖含量与α-淀粉酶的活性成反比,说明可溶性糖对α-淀粉酶的活性有反馈抑制作用。种子萌发之前具有较高的β-淀粉酶活性,并且未受高浓度可溶性糖的抑制,萌发之后活性显著下降。表明较高的β-淀粉酶活性对野杏种子打破休眠是必要的。

In this study, the seeds of two species of wild apricot （Armeniaca vulgaris Lam） , bitter kernel （Armeniaca vulgaris f. aurantica L. Wang et D. F. Cuiand） and sweet kernel （Armeniaca vulgaris f. glyeyosma L. Wang et D. F. Cui. ）, were collected. The effects of GA on the physiological indexes of the wild apricot seeds, such as the breaking to the dormancy of wild apricot seeds, dynamic changes of starch content and soluble sugar content in seed cotyledon, and amylase activity in seed embryo of wild apricots, are researched. The results show that GA could increase the germination percentage of wild apricot, especially that of sweet kernel apricot. Starch contents in seed cotyledon was immediately decreased after sopping up, but the soluble sugar content was significantly increased, and then decreased after the seeds of both bitter and sweet kemel apricots germinated, a-amylase and β-amylase activity in dry seeds was observed, the result shows that α-amylase activity in germinating seeds was higher than that in non-germinating seeds. An inverse correlation between soluble sugar content and a-amylase activity reveals that soluble sugar had a restrictive feedback effect on α-amylase activity. There was a high β-amylase activity in seeds before germination, and β-amylase activity was unaffected by high concentration of soluble sugar. The β-amylase activity was significantly decreased after germination. These results show that the high β-amylase activity is necessary for breaking the dormancy of wild apricot seeds.