遮光对两种兰科植物叶绿素荧光参数的影响  

Effects of Shading on Chlorophyll Fluorescence Parameters of Two Orchid Species

作　　者：邓施琴 美朵卓嘎 张欢 罗建[1,2,3] DENG Shiqin;Meiduozhuoga;ZHANG Huan;LUO Jian(Institute of Plateau Ecology,Xizang Agricultural and Animal Husbandry University;Key Laboratory of Xizang Plateau Forest Ecology of Ministry of Education&National;Field Scientific Observation and Research Station of Xizang Nyingchi Mountane Forest Ecosystem;College of Forestry and Grassland,Nanjing Forestry University/Co-Innovation Center for Sustainable Forestry in Southern China;College of Resources and Environment,Xizang Academy of Agriculture and Animal Husbandry)

机构地区：[1]西藏农牧学院高原生态研究所,西藏林芝860000 [2]西藏高原森林生态教育部重点实验室,西藏林芝860000 [3]西藏林芝高山森林生态系统国家野外科学观测研究站,西藏林芝860000 [4]南京林业大学林草学院,南方现代林业协同创新中心,江苏南京210037 [5]西藏农牧学院资源与环境学院,西藏林芝860000

出　　处：《北方园艺》2024年第22期38-47,共10页Northern Horticulture

基　　金：国家自然科学基金资助项目(31560054);第二次青藏高原综合科学考察研究资助项目(2019QZKK05020110);国家科技基础资源调查专项资助项目(2021FY100201);西藏高原森林生态教育部重点实验室研究生创新计划资助项目(XZA-JYBSYS-2023-24)。

摘　　要：以黄蝉兰(Cymbidium iridioides)和莎草兰(C.elegans)为试材,采用遮光法比较4个不同梯度遮光处理下二者的光合色素和叶绿素荧光参数的差异,揭示这2种兰科植物适合生长的光照条件,以期为西藏兰科物种的保护和可持续利用提供参考依据。结果表明:在4个遮光条件下光合色素含量显著变化,黄蝉兰在40%遮光条件,莎草兰在20%遮光条件下光合色素含量最高;Fm、Fv/Fm和Fv/Fo随遮光强度加大,均呈现上升趋势,在60%遮光条件下达最高;2种兰科植物的光合电子传递能力总体表现为随遮光强度加大呈逐步下降的趋势,在80%遮光条件下降速加剧;黄蝉兰在40%、莎草兰在20%的遮光条件下,叶片PSⅡ的电子传递活性最强,在80%遮光条件下2种兰科植物叶片PSⅡ的电子传递活性出现抑制现象;黄蝉兰在40%、莎草兰在20%的遮光条件下热耗散最高,2种兰科植物在80%遮光条件下PSⅡ的热耗散最弱。在适度遮光条件下,促进2种兰科植物提高光合效率,有利于植株生长;过度遮光导致光合色素降低,光能传递和转化受限,植株生长不良。2种兰科植物在耐阴性上有所差异,黄蝉兰的耐阴性大于莎草兰。黄蝉兰最适遮光条件为40%,莎草兰最适遮光条件为20%。Taking Cymbidium iridoides and C.elegans as the test materials,the differences of photosynthetic pigments and chlorophyll fluorescence parameters between them under four different gradient shading treatments were compared by shading,revealing the light conditions suitable for the growth of these two orchids,in order to provide reference for the protection and sustainable use of orchid species in Xizang.The results showed that photosynthetic pigment content significantly changed under the four shading conditions. C.iridioides had the highest pigment content under 40% shading,while C.elegans had the highest pigment content under 20% shading. Fm,Fv/Fm,and Fv/Fo showed an increasing trend with the increase in shading intensity,reaching a significant maximum under 60% shading.The photosynthetic electron transport capacity of both species generally decreased with the increase in shading intensity,with a marked decline under 80% shading.The electron transport activity of PSⅡ in the leaves of C.iridioides was the strongest under 40% shading,while for C.elegans it was strongest under 20% shading;both species exhibited inhibited electron transport activity of PSⅡ under 80% shading.Thermal dissipation in the leaves was the highest under 40% shading for C.iridioides and 20% shading for C.elegans,while the weakest thermal dissipation of PSⅡ was observed under 80% shading for both species.The conclusion was that moderate shading conditions promoted increased photosynthetic efficiency and benefited plant growth,whereas excessive shading led to a decrease in photosynthetic pigments,restricted light energy transfer and conversion,and poor plant growth.The two species showed differences in shade tolerance,with C.iridioides exhibiting greater shade tolerance than C.elegans.The optimal shading condition was 40% for C.iridioides and 20% for C.elegans.

关 键 词：遮光 黄蝉兰 莎草兰 叶绿素荧光 光合色素 

分 类 号：S682.31[农业科学—观赏园艺]