亚热带落叶与常绿园林树种非结构性 碳水化合物的季节动态比较

非结构性碳水化合物(Non-structural carbohydrates,NSC)含量可较好地表征植物对环境的适应性。该研究比较分析了亚热带地区常见的落叶与常绿2种生活型园林树种的叶和枝中NSC(可溶性糖、淀粉)的含量及其季节变化,以探讨不同生活型植物对亚热带气候的适应方式。结果表明:(1)落叶和常绿树种叶的NSC含量差异明显,落叶树种的为15.71%,而常绿树种的达19.24%;(2)落叶和常绿树种叶和枝的NSC含量均呈现明显的季节动态,叶可溶性糖含量随季节变化逐渐升高、而淀粉含量呈下降的趋势; 2种生活型树种1年生枝的可溶性糖含量都表现为上升的趋势,落叶树种的淀粉含量呈“∧”形变化,常绿树种的呈逐渐下降趋势,但落叶树种叶的可溶性糖和枝的淀粉含量季节波动更大;(3)落叶树种的叶可溶性糖与多年生枝的淀粉含量表现为显著负相关,而与1年生枝的关系不显著; 常绿树种叶可溶性糖与1年生枝的可溶性糖含量呈正相关,而与多年生枝的相关性不显著。总之,落叶和常绿树种对亚热带气候存在不同的糖转移和转化适应机制。

A comparison of seasonal dynamics of nonstructural carbohydrates for deciduous and evergreen landscape trees in subtropical region,China

Non-structural carbohydrate(NSC)is a good indicator for plant adaptation to the environment. In order to investigate different life form plants adapting to the way of subtropical climate, the content of NSC(soluble sugar and starch)in the leaves and branches of two common deciduous and evergreen landscape tree species in subtropical region were measured seasonally.The results showed that(1)The content of NSC in leaves was different between deciduous and evergreen trees, the soluble sugar was 15.71% in deciduous tree species, while it was up to 19.24% in evergreen trees.(2)The content of all NSC components in leaves and branches of two life form trees showed significant seasonal dynamics,with a rising trend of soluble sugar, a falling trend of starch in two kind of leaves. The content of soluble sugar in one-year-old branch showed a rising trend in two life forms, a “∧” shape of starch for deciduous and a falling trend for evergreen trees. But the seasonal dynamic rate of the soluble sugar in leaves and the starch in branches were faster for deciduous trees than that for evergreen trees.(3)There was a significant negative relationship between the contents of the soluble sugar in leaves and starch in perennial branches for deciduous trees, but not for one-year-old branches. The contents of the soluble sugar in leaves and one-year-old branches were significantly and positively correlated for evergreen trees. These studies indicated that there were different mechanisms of sugar transformation and translocation between deciduous and evergreen trees to adapt subtropical climate.