中甸角蒿光合作用对生长光强的响应

Photosynthetic Response of Incarvillea zhongdianensis (Bignoniaceae) Subject to Growth Irradiance

在原生地和引种地对高山花卉中甸角蒿(1ncarvillea zhongdianensis)光合作用和叶片性状对生长光强的响应进行研究。结果表明:在香格里拉,光合速率(Pn)、类胡萝卜素(Car)、色素比(Chla/b)均随光强的降低而下降;而比叶面积(SLA)、叶绿素b(Chlb)、叶氮含量(LNCa)随光强的降低而上升。中甸角蒿主要是通过叶片形态、生化效率和叶片氮分配来响应生长光强的变化,对生长光强的适应表现出较大可塑性,使得其相对比较容易引种驯化。中甸角蒿在香格里拉对光照具有较广的适应幅,从香格里拉移栽到昆明后,虽然Pn下降约10%,但RGR增加约30%,表明其可以在昆明较好生长。

Photosynthesis and leaf traits of Incarvillea zhongdianensis grown in different growth irradiances were investigated in Shangri-La and Kunming. The results showed that the photosyhthetic rate（Pn）,content of carotenoids（Car）,ratio of chlorophyll a to b（Chla/b）in I.zhongdianensis decreased with the decreasing irradiance in Shangri-La,while specific leaf area（SLA）,chlorophyll b（Chlb）,leaf nitrogen content per unit area（LNCa）increased. The photosynthetic acclimation of I.zhongdianensis to growth irradiance was mainly dependent on the adjustment of leaf anatomy,biochemical efficiency and leaf nitrogen partitioning into different photosynthetic components. This species showed a large plasticity in photosynthetic response to light intensity,which was contributive to its introduction and domestication. I.zhongdianensis had wide adaption for irradiance in Shangri-La,after transplanted to Kunming,Pn decreased about 10%,but relative growth rate （RGR）increased 30%,which indicated that it could grow well under the irradiance condition of Kunming.