遮阴对少叶花楸幼苗光合和叶绿素荧光参数的影响  

Effects of Shading on Photosynthetic and Chlorophyll Fluorescence Response of Sorbus hupehensis var. paucijuga

作　　者：赵洋 陈云[1] 张晓晨 熊中人 陈昕[1] Zhao Yang;Chen Yun;Zhang Xiaochen;Xiong Zhongren;Chen Xin(Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,P.R.China)

机构地区：[1]南方现代林业协同创新中心(南京林业大学),南京210037

出　　处：《东北林业大学学报》2019年第1期30-34,共5页Journal of Northeast Forestry University

基　　金：江苏省林业三新工程(LYSX[5015]42);江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：以1年生少叶花楸幼苗为试验材料,采用遮阳网遮光方式设置遮阴度为0、25%、36%、50%、76%、92%6种处理,测定少叶花楸幼苗光合及叶绿素荧光参数,探讨少叶花楸对光照强度的适应。结果表明:在6种处理下,净光合速率和气孔导度日变化均呈单峰曲线,未出现光合"午休现象"。遮阴使少叶花楸幼苗净光合速率、蒸腾速率、气孔导度减小,胞间CO_2摩尔分数增大;叶绿素a质量分数、叶绿素b质量分数和叶绿素总质量分数均随着遮阴度的增加而增大,分别比全光照增加了62.16%、131.37%和83.95%,叶绿素a质量分数/叶绿素b质量分数和类胡萝卜素质量分数随着遮阴度的增加而减小,分别比全光照减小了30.45%和28.57%;遮阴使叶片光能转换效率、有效量子效率、PSⅡ实际光化学效率和光化学淬灭系数增大,最大值分别比全光照增加了6.85%、22%、17.14%和24.59%,非光化学淬灭系数比全光照减小了60.54%。综合表明,适度遮阴诱发了少叶花楸幼苗的光合和生理适应机制。因此,在少叶花楸的引种和栽培过程中,适当遮阴有利于提高其苗木质量。An experiment was conducted to study the photosynthetic characteristic and chlorophyll fluorescence parameters of one-year Sorbus hupehensis var.paucijuga seedlings under six shade levels(0,25%,36%,50%,76%and 92%).The diurnal variation of leaf net photosynthetic rate and stomatal conductance of seedling under different shading treatments could be described with a unimodal curve.The net photosynthetic rate,transpiration rate and stomatal conductance were decreased with the decreasing light intensity.With a decrease in light intensity,chlorophyll a,chlorophyll b and total chlorophyll content were increased,which were increased by 62.16%,131.37%and 83.95%when compared to CK,respectively;but chlorophyll a/b and carotenoid contents were decreased,which were reduced by 30.45%and 28.57%compared to CK,respectively;light energy conversion efficiency,effective quantum efficiency,the actual photochemical efficiency of PSⅡand photochemical quenching were increased with the increase of shading intensity,increased by 6.85%,22%,17.14%and 24.59%compared to CK,respectively,and non-photochemical quenching coefficient decreased by 60.54%.The results showed that shading stimulated the photosynthetic and physiological adaptation mechanisms in S.hupehensis var.paucijuga seedling,and moderate shading could improve plant quality during the nursery period.

关 键 词：遮阴 少叶花楸 光合特性 叶绿素荧光 

分 类 号：S685.12[农业科学—观赏园艺] Q945.11[农业科学—园艺学]