文档介绍:遮阴对高山杜鹃叶片解剖和光合特性的影响
 
 
宋杰 李树发 李世峰 蔡艳飞
摘 要:為了解高山杜鹃对光能的需求和适应性,该研究以盆栽3 a生高山杜鹃品种cv. Furnivalls Daughter为材e tissue were higher, while that of stomatal-related parameters such as stomatal density, stomatal length and width were lower, which indicates that mesophyll tissue plays a more important role in the process of adaption to different light environments. The analysis of light response curves and photosynthetic parameters showed that the plants of 100% full light intensity were inhibited and damaged by strong light, and the plants showed the lowest light saturation point (LSP), net photosynthetic rate (Pn), photosynthetic rate at light saturation point (Pmax), stomatal conductance (Gs) and transpiration rate (Tr). After shading treatments, Pn, Pmax, Gs, Tr and light use efficiency (LUE) were improved. Compared with other shading
treatments, the plants of 30% full light intensity not only had the lowest light compensation point (LCP), dark respiration rate (Rd), but also had the highest LSP, Pn, Pmax, Gs, Tr and LUE. The above results suggest that the optimum light intensity of Rhododendron  cv. Furnivalls Daughter in Kunming is about 30% full light intensity. In the cultivation and application of Rhododendron, we should take some shading measures to meet the optimum light conditions for its growth.
Key words:Rhododendron, anatomical structure, photosynthesis, light
高山杜鹃是杜鹃花中的一大类,一般指无鳞杜鹃花亚属、有鳞杜鹃花亚属、马银花亚属中的常绿杜鹃,以及它们的杂交品种(李倩等,2009)。高山杜鹃色彩鲜艳,花姿优美,株型漂亮,具有极高的经济价值和观赏价值(李志斌等,2007)。然而,在高山杜鹃的栽培及园林应用过程中发现,光照对高山杜鹃的生长发育具有重要影响。强光下高山杜鹃的生长缓慢,叶片发黄,并伴有日灼现象发生,而过度遮阴则会导致高山杜鹃的枝条徒长,株型散乱,花芽数量减少,花色变淡,大大降低高山杜鹃的观赏性和经济价值(郑宝强等,2010)。
光照是影响植物形态和功能的重要因子,对植物的生长、发育和演化具有极其重要的作用(Aleric & Kirkman,2005;Sofo et al., 2009;裘珍飞等,2017;赵斌等,2017)。植物在长期适应不同光环境的过程中,其叶片形态和生理特性会发生相应改变,以最大程度维持光合能力,从而适应不同的光环境(Evans,1989;Cregg et al., 1993;Niinemets & Tenhunen,1997;Pandey
et al., 2009)。植物对环境的适应能力直接或间接地与光合能力相关,反过来环境因子对植物叶片的结构和功能产生影响,进而影响整个植株的生长(Chandra,2003;吴正花等,2018)。近年来,关于杜鹃属植物形态结构与环境适应关系已引起科