变温层积过程中圆齿野鸦椿种子内含抑制物的生理活性变化

Changes of physiologically activity of inhibitor in Euscaphis konishii seeds during variable temperature stratification

为了探明圆齿野鸦椿种子发芽抑制物的存在部位及其在贮藏过程中抑制活性的变化情况,于变温层积(4℃冷温层积3个月、25℃暖温层积3个月、4℃冷温层积3个月)各阶段前、后分别取种子测定其种仁和种壳中内含抑制物的生理活性;并分别以甲醇和蒸馏水为浸提剂,制备圆齿野鸦椿种仁、种壳浸提液,研究各浸提液对白菜种子发芽及幼苗生长的影响,以分析在变温层积过程中圆齿野鸦椿种子内含抑制物的生理活性变化情况。结果表明:圆齿野鸦椿种仁和种壳中均含有发芽抑制物和生长抑制物;随着浸提液质量浓度的升高,抑制物生理活性逐渐增强;甲醇浸提液抑制物的生理活性极显著高于蒸馏水浸提液抑制物;种仁浸提液抑制物的生理活性极显著高于种壳浸提液抑制物。随着变温层积处理的进行,种子内含抑制物生理活性逐渐降低,但种子经变温层积9个月后,以0.20 mg·L-1的种仁甲醇浸提液处理的白菜种子其相对发芽率仅为46.7%,白菜幼苗的相对茎长为34.3%、相对根长为41.7%,这表明圆齿野鸦椿种子经9个月的变温层积处理后其抑制物的生理活性仍较强,说明该种子具有深度休眠的特性。

In order to learn location of inhibitory substances in Euscaphis konishii seed and change of inhibitory activity during stratification, physiologically activities of inhibitor in kernel and shell were determined at various stages of variable temperature stratification （4 ℃, 3 months; 25 ℃, 3months; 4 ℃, 3months）. Leaching solutions of kernel and shell in E. konishii were prepared by using methanol and distilled water as extraction solvents. Effects of different leaching solution on seed germination and seedling growth in Brassica campestris and changes of physiological activity of inhibitor in E. konishii seed were researched during variable temperature stratification. The results indicate that germination inhibitors and growth inhibitors exist in both kernel and shell of E. konishii. With increasing mass concentration of leaching solution, physiological activity of inhibitor is increased gradually. Physiologically activity of inhibitor in methanol leaching solution is significantly higher than that in distilled water leaching solution. Physiologically activity of inhibitor in kernel leaching solution is significantly higher than that in shell leaching solution. Physiologically activity of inhibitor in seed is decreased gradually during variable temperature stratification. Taking seeds stored through variable temperature stratification for nine months as materials, relative germination rate of Brassica campestris seeds is 46.7%, which is treated by 0.20 mg.L-l methanol leaching solution of kernel, and relative stem length and relative root length of seedlings are 34.3% and 41.7% respectively. It indicates that inhibitor in E. konishii seed remains strong physiological activity after variable temperature stratification for nine months. So Euscaphis konishii seed has the characteristic of deep dormancy.