箭叶淫羊藿叶片光合作用对光强的响应

Response of Epimedium sagittatum Leaf to Illumination

设置弱光(1/10全光照)和强光(1/4全光照)两个光照梯度,探讨了箭叶淫羊藿(Epimetium sagittatum)叶片光合作用对光强的响应,结果表明:两光强下箭叶淫羊藿叶片的光饱和点均小于1 000μmol·m-2·s-1,而光补偿点分别只有13.825和17.168μmol·m-2·s-1,说明该物种属于典型的阴生植物;与强光处理相比,弱光下箭叶淫羊藿叶片的最大光合速率(Pmax)、量子效率(α)、气孔导度(Gs)、水分利用效率(WUE)以及电子传递速率(ETR)均较高,而孔限制值(Ls)则较低,说明较弱光强更适合箭叶淫羊藿的生长。综合光合速率和ETR对光强的响应,建议对箭叶淫羊藿进行人工栽培或野生抚育时,其最大光强不高于400μmol·m-2·s-1为宜。

Epimetium brevicornu is one of rheumatism medicine in China. It is a particular rare and endangered plant. The biodiversity conservation of E. brevicornu is timely needed. The purpose of this paper was to determine the effect of light intensities on the photosynthetic physiology response of E. brevicornu, and offer some suggestion to the conservation. Based on indoor culture of two light intensities, i.e. 25%（High） and 10%（Low） sunlight, photosynthetic characteristics of E. brevicornu were studied, respectively. The results showed that the light saturation point of two light intensities were below 1 000 μmol·m-2·s-1, and the light compensation point was 13.825 and 17.168 μmol·m-2·s-1, respectively. It illustrate that E. brevicornu belongs to the typical shade plant. Compared to the 25% sunlight, the maximum photosynthetic rate, photosynthetic quantum yield, stomatal conductance, water use efficiency and stomatal limitation value were all higher. According to our comprehensive experiment, E. brevicornu could grow better in relative low light intensity environment（﹤400 μmol·m-2·s-1）.