【摘要】 采用室内沙培方式,设计不同光强(2水平)和N浓度(4水平)处理,探讨1年生水曲柳幼苗叶片光合速率和荧光参数对环境变化的生理响应。结果表明:与全光照相比,遮光处理使苗木叶片最大光合速率(Amax)、光补偿点(LCP)以及光化学猝灭系数(qP)明显下降,但使表观量子效率(AQY)、最大荧光(Fm)和最大光化学效率(Fv/Fm)明显增加。同时,苗木叶片单位面积的叶绿素a、类胡萝卜素、总叶绿素含量以及叶绿素a/b在遮光条件下较低。2种光强下的Fm、Fv/Fm、φPSⅡ和qP均随着供N浓度的增加而显著增加(P<0.05),其中φPSⅡ在低N时增加较快而高N时较慢,甚至略有下降。光强和N浓度在水曲柳苗木叶片Fm、φPSⅡ、Fv/Fm、qN以及qP上均具有显著的交互作用(P<0.05)。更多还原

【Abstract】 One-year old Fraxinus mandshurica seedlings were sand-cultured and subjected to different light intensity (2 levels) and N supply (4 levels) to examine their photosynthetic rate and chlorophyll fluorescence response to environmental change. The results showed that comparing with full light, shading decreased the maximum photosynthesis rate (Amax), light compensation point (LCP) and photochemical quenching coefficient (qP) obviously, while increased the apparent quantum yield (AQY), maximum fluorescence (Fm) and maximal photochemical efficiency (Fv/Fm) markedly. The total chlorophyll, chlorophyll a and carotenoid contents and chlorophyll a/b per unit area of leaf were lower under shading. At two light levels, the Fm, Fv/Fm, φPSⅡ and qP increased with increasing N supply (P<0.05), and φPSⅡ increased more quickly at lower N levels than at higher N levels. Light intensity and N supply had a significant interaction on the Fm, φPSⅡ, Fv/Fm, qN and qP (P<0.01).更多还原