高CO_2浓度下豆科4种乔木幼苗的生理生化反应

PHYSIOLOGICAL AND BIOCHEMICAL RESPONSES OF THE SEEDLINGS OF FOUR LEGUME TREE SPECIES TO HIGH CO 2 CONCENTRATION

本文对４种豆科乔木幼苗在高ＣＯ２浓度（５５０×１０－６±５０×１０－６）和在对照ＣＯ２浓度（约为３５０×１０－６）下生长的幼苗的一些生理生化指标进行了比较研究。初步结果显示：高ＣＯ２浓度能缩短幼苗子叶的存活时间。高ＣＯ２环境下生长的４种幼苗叶片中的可溶性蛋白、可溶性糖、纤维素、Ｎ、Ｐ、Ｋ、Ｍｇ的含量（均为全量）较对照ＣＯ２环境下生长的幼苗的相应值低，而淀粉含量则较高。其中以全氮、可溶性糖差异较显著。以单位鲜重表示的幼苗叶片叶绿素（Ｃｈｌ）和类胡萝卜素（Ｃａｒ）含量降低。高ＣＯ２浓度下生长的４种幼苗（３０天龄）叶片中硝酸还原酶活性比对照ＣＯ２浓度下生长的幼苗的值低。高ＣＯ２浓度下生长的４种幼苗叶片的平均蒸腾速率有不同程度的降低，而气孔阻力升高。幼苗对高ＣＯ２环境的反应与种的生态特性有关。喜光的大叶合欢幼苗对高ＣＯ２环境的反应较大，喜光而具一定耐荫性的猴耳环幼苗次之。

Some physiological and biochemical characteristics were studied comparatively for the seedlings of four legume tree species growing in ambient(about 350×10 -6 )and higher(550±50×10 -6 )CO 2 concentration. Cotyledons appeared to keep shorter life(7%～13%)in the seedling growing in the higher CO 2 concentration than those in ambient CO 2 concentration. Seedlings growing in the higher CO 2 concentration showed higher(11%￣19%)stomatal resistance and lower(9%～20%)transpiratory rate. Seedlings growing in the higher CO 2 concentration had lower contents of chlorophyll and carotenoid(based on leaf weight), lower contents of soluble protein, soluble sugar, cellulose and total N,P,K and Mg, and higher content of starch in leaves, as compared with the seedling in ambient CO 2 concentration had. The responses to the higher CO 2 concentration were different among the species. Seedling of sunny species Albizzia lebbeck showed the most obvious response, while the two shade tolerant species Ormosia glaberrima and Ormosia pachycarpa showed the least responses.