李正华　李海霞　于文喜等

摘要 [目的]研究秋末迎春5号杨叶片生理指标变化，探讨叶片内各物质的变化规律及其之间的关系。[方法]在不同时间点采集杨树一年生叶片，测定光合色素、可溶性糖、黄酮和总酚含量。[结果]随气温降低，叶片中光合色素均呈下降趋势，叶绿素、叶绿素a、叶绿素b含量与温度变化呈极显著正相关；Car/Chl、Chla/Chlb比值上升，其中Car/Chl比值与温度间呈极显著负相关；可溶性糖、黄酮和总酚含量均升高，前二者与温度变化呈强负相关，而总酚含量相关性不强。[结论]叶片中Car/Chl及Chla/Chlb比值的上升，可能是杨树叶片抗寒能力增强的重要指标。

关键词 光合色素；可溶性糖；黄酮；总酚

中图分类号 S792.11 文献标识码 A 文章编号 0517-6611（2015）20-201-03

Abstract [Objective]Experiments were carried out to study the changes of physiological indexes and the relation among the material of the Yingchun poplar 5 in late autumn.[Method]The content of photosynthetic pigment，soluble sugar，flavonoid and total phenols of annual poplar leaves at different time points were measured.[Result]The results showed that the content of photosynthetic pigment decreased with the temperature declining.Chlorophyll，chlorophyll a and chlorophyll b content presented significantly positive correlation to temperature.Car/Chl、Chla/Chlb ratio rose.The results showed a highly significant negative correlation between Car/Chl and temperature.The contents of soluble sugar，flavonoid and total phenols increased with the temperature decreased.The negative correlation between temperature and soluble sugar as flavonoid was significant .There was no correlated between total phenols and temperature.[Conclusion]The Car/Chl and Chla/Chlb in leaf may be the important indexes of poplar leaf cold tolerance.

Key words Photosynthetic pigment；Soluble sugar； Flavonoid；Total phenols

楊树是我国重要的造林树种之一，因其生长迅速、材性优良、树形优美，被大量用于营造工业用材林、生态防护林以及城市园林绿化，是我国北方种植面积最大的树种[1-2]。众多环境因子中，低温冻害是影响我国北方地区杨树产业发展重要因素，加上近年来频频出现的气候反常现象，使杨树植物更易遭受春秋季节低温胁迫。

20世纪60年代以前，关于杨树抗冻性研究仅限于一般冻害调查。近年来，有关杨树抗寒性方面的研究，主要集中在生理生化及细胞形态方面[3-4]。这些探索与研究涉及的杨树抗冻性多限于形态结构分析、品种间抗冻性强弱比较及初生代谢指标的测试。植物在长期进化中与环境相互作用形成的次生代谢，在提高自身保护和生存竞争能力、协调与环境关系上充当着重要的角色，次生代谢产物的产生和变化比初生代谢产物与环境有着更强的相关性和对应性。……