干旱对6种野生花卉光合色素含量与气体交换的影响

Effects of Drought Stress on Photosynthetic Pigment Content and Gas Exchange in Leaves of Six Wild Flowers

为给野生耐旱花卉在城市绿化中的应用提供理论依据,在温室内用盆栽法测定了燕山地区6种野生耐旱花卉苗木干旱胁迫进程中的对照、干旱胁迫5d、暂时萎蔫和永久萎蔫4点的光合色素含量与气体交换变化。结果表明:在土壤干旱进程的对照、干旱5d、暂时萎蔫和永久萎蔫各时间的总叶绿素、类胡萝卜素和叶绿素a与叶绿素b比值,除栓翅卫矛、孩儿拳头和木半夏各自的总叶绿素含量没有明显差别外,其余各自的总叶绿素含量、类胡萝卜素含量和叶绿素a与叶绿素b比值等指标的差异均显著或极显著;随土壤含水量降低,6种苗木蒸腾速率、净光合速率和气孔导度总体呈下降趋势,在永久萎蔫点三项指标降低幅度排序:蒸腾速率为木半夏>蚂蚱腿子>南蛇藤>孩儿拳头>叶底珠>栓翅卫矛;净光合速率为孩儿拳头>叶底珠>蚂蚱腿子>南蛇藤>木半夏>栓翅卫矛;气孔导度为蚂蚱腿子>叶底珠>孩儿拳头>南蛇藤>木半夏>栓翅卫矛;不同苗木的光合色素含量和三个指标对干旱胁迫的反应不同预示各苗木具有不同适应干旱的机理。

In order to provide a theoretical basis for application of wild drought tolerant flowers in city greening, photosynthetic pigment content and gas exchange changes of leaves were determined by pot culture method under the conditions of control, 5 days under drought stress, temporary wilting and permanent wilting in greenhouse, taking six wild drought tolerant flowers from Yanshan areas as materials. The results showed that there were significant and very significant differences among total chlorophyll contents, carotene contents and ratios of chlorophyll a to chlorophyll b in the flowers under the conditions, except Securinega suffruticosa, Elaeagnus multi flora, Euonyrnu phellomanus. With water content in soil decreased, transpiration rate, net photosynthetic rate and stomata conductance of six flowers declined on the whole. The decreased degree order of transpiration rate from high to low under the condition of permanent wilting was E. multiflora, Myripnois dioica, Celastrus orbiculatus, Grewia biloba, S. suffruticosa, E. phellomanus, that of net photosynthetic rate was G. biloba, S. suffruticosa, M. dioica, C. orbiculatus, E. multi flora, E. pheUomanus, and that of stomata conductance was M. dioica, S. suffruticosa, G. biloba, C. orbiculatus, E. multi floraE. phellomanus. The results indicated that the six wild flowers had different drought tolerant mechanisms.