摘要
采用不同浓度的Cu处理喜树种子和三叶期的幼苗,研究了Cu胁迫对喜树种子萌发和幼苗生长及生理代谢的动态影响。结果表明：（1）20～50 mg·L^-1的Cu^2＋对喜树种子发芽率有一定的促进作用,发芽势提前,但50～100 mg·L^-1的Cu^2＋浓度均抑制胚根和胚芽的生长。（2）Cu^2＋对喜树幼苗的影响存在浓度和时间效应：低浓度（10 mg·L^-1）Cu^2＋促进,如叶绿素含量、蛋白质含量等高于对照;高浓度（100 mg·L^-1）Cu^2＋对上述各指标从6 d或9 d后起显著地抑制作用;而中等浓度（50 mg·L^-1）的Cu^2＋处理效果趋向于高浓度的作用。低浓度的Cu在12 d之内对喜树幼苗生长是有利的,以后会出现胁迫;而高浓度的Cu,3 d后出现抑制,抑制作用比低浓度提早9 d。说明喜树幼苗能够忍受小于50 mg·L^-1以下的Cu处理,高于此浓度生长受抑。（3）Cu处理后质膜相对透性、MDA含量在整个处理期内呈上升趋势,浓度越大,上升幅度越大;而SOD、POD活性先上升后下降,与Cu浓度存在极显著的相关性。
In this paper, we studied the effects of copper stress on seeds germination, growth and physiological indices for seedlings of Camptotheca acuminata Decne treated by gradient [Cu^2＋] under 0, 10. 0, 20. 0 （not adding in seedlings） ,50. 0, 100. 0 mg·L^-1 for 12 or 15 days respectively. The results showed that： （1）The germination rate of seeds increased under 20～50 mg·L^-1 of Cu^2＋ , whereas the growth of embryo roots and buds were found to be significantly inhibited under all the tested Cu^2＋ concentrations; （2） There existed concentration and time effects on plants with the different [Cu^2＋] treatment： Chlorophyll and soluble protein content in the leaves increased, which was in contrast that the height of shoots, length and activity of root were not significantly inhibited in low [Cu^2＋] （10 mg·L^-1）. But these indices decreased after 6～9 days＇ under high [Cu^2＋]（100 mg·L^-1）. The effect of middle[Cu^2＋]（50 mg·L^-1） was between that of the low and the high [Cu^2＋] and in general, it inhabited the growth of seedling. Short-term treatment with 10 mg·L^-1 Cu^2＋ was found to benefit the seedlings growth, while twelve days later, stress was observed even in low Cu^2＋. Under high [Cu^2＋], stress was observed after 3 days of treatment; （3） The member permeability, MDA content in the leaves increased throughout the period of treatment and increased significantly with Cu^2＋ concentration and treatment time. Initially, the activities of SOD, POD of the leaves increased and then decreased in leaves and these indices were significantly correlated with [Cu^2＋]. As the conclusion, the seedlings could endure [Cu^2＋] lower than 50 mg·L^-1 for a short term, but growth would be inhabited much sooner when treated with higher [Cu^2＋].
出处
《西北林学院学报》
CSCD
北大核心
2008年第2期1-6,90,共7页
Journal of Northwest Forestry University
基金
科技部林业科技支撑计划(2006BAD18B0301)
关键词
喜树
CU胁迫
浓度和时间效应
生理代谢
Camptotheca acuminata
copper stress
concentration and time effect
physiological metabo-lism
