欢迎访问《生态学杂志》官方网站,今天是 分享到:

生态学杂志 ›› 2021, Vol. 40 ›› Issue (4): 980-988.doi: 10.13292/j.1000-4890.202104.013

• 研究报告 • 上一篇    下一篇

光照强度对濒危植物长序榆光合特性的影响

罗光宇1,2,3,陈超1,2,3,李月灵2,3,金则新2,3*   

  1. 1上海师范大学生命科学学院, 上海 200234; 2台州学院生态研究所, 浙江台州 318000; 3台州学院浙江省植物进化生态学与保护重点实验室, 浙江台州 318000)
  • 出版日期:2021-04-10 发布日期:2021-04-12

Effects of light intensity on the photosynthetic characteristics of Ulmus elongata.

LUO Guang-yu1,2,3, CHEN Chao1,2,3, LI Yue-ling2,3, JIN Ze-xin2,3*   

  1. (1College of Life Sciences, Shanghai Normal University, Shanghai 200234, China; 2Institute of Ecology, Taizhou University, Taizhou 318000, Zhejiang, China;3Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, Zhejiang, China).
  • Online:2021-04-10 Published:2021-04-12

摘要: 为探讨濒危植物长序榆(Ulmus elongata)对不同光环境的光合适应机制,以2年生幼苗为对象,调查了自然光照的100%(I100)、40%(I40)和10%(I10)3种光照强度对植株光合特性的影响。结果表明:(1)3种光强下长序榆的净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)的日变化均呈“单峰型”曲线;胞间CO2浓度(Ci)的变化则呈“V型”曲线;3种光强下植株的PnGs、水分利用率(WUE)日均值均为I100>I40>I10。日均Ci大小为I10>I100>I40。I10的日均Tr显著低于I100、I40。(2)长序榆幼苗的最大净光合速率(Pnmax)、光饱和点(LSP)、光补偿点(LCP)、暗呼吸速率(Rd)均以I100最大;最大羧化速率(Vcmax)、磷酸丙糖利用率(TPU)均为I100>I40>I10;I10的最大电子传递速率(Jmax)显著低于I100、I40。(3)遮荫处理导致长序榆叶片PSII最大光量子产量(Fv/Fm)和PSII实际光量子产量(Fv′/Fm′)增加;I100的非光化学淬灭系数(NPQ)、光化学淬灭系数(qp)显著高于I40、I10。分析表明,长序榆幼苗在全光照环境下叶片所吸收的光能主要通过天线热耗散以散发过剩的光能;遮荫处理叶片光能较多地分配于光化学反应和非光化学反应耗散部分;长序榆在强光照高温下未发生明显的光抑制,也未出现光合“午休”现象,碳同化效率高,表现出阳性植物的特点;光照不足可能是长序榆幼苗林下自然更新的限制因子。

 

关键词: 长序榆, 光照强度, 光合作用参数, 光响应, CO2响应, 叶绿素荧光参数

Abstract: To explore the photosynthetic adaptation of the endangered species Ulmus elongata to different light conditions, two-year-old seedlings were planted under different shading treatments, i.e. 100% of natural light (I100), 40% of natural light (I40), and 10% of natural light (I10). We analyzed the effects of different light intensities on the photosynthetic characteristics of U. elongata. The results showed that: (1) The diurnal variations of the net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) of U. elongata under all the three light intensities presented “singlepeak” curves, with a peak at about 12:00. In contrast, the diurnal variation of the intercellular CO2 concentration (Ci) exhibited a “Vshaped” pattern. The daily mean values of Pn,Gs, and water use efficiency (WUE) under three light intensities ranked as I100>I40>I10, while those of Ci ranked as I10>I100>I40. The daily mean value of Tr under I10 treatment was significantly lower than that under the I100 and I40 treatments. (2) The maximum net photosynthetic rate (Pnmax), light saturation point (LSP), light compensation point (LCP), and dark respiration rate (Rd) of U. elongata seedlings uniformly occurred under I100 treatment. Both the maximum carboxylation rate (Vcmax) and triose phosphate utilization rate (TPU) ranked as I100>I40>I10. The maximum electron transfer rate (Jmax) under I10 treatment was significantly lower than that under I100 and I40 treatments. (3) Shading increased PSII maximum photon yield (Fv/Fm) and PSII actual photon yield (Fv′/Fm′). The non-photochemical quenching coefficient (NPQ) and photochemical quenching coefficient (qp) under I100 treatment were significantly higher than those under I40 and I10 treatments. Light energy absorbed by the leaves of U. elongata seedlings in the fulllight environment was dissipated mainly in the form of antenna heat. The majority of light energy in leaves under the shading treatment was distributed to the photochemical reaction and non-photochemical reaction dissipation part, with little remained for antenna heat dissipation. Collectively, there was no obvious photoinhibition in U. elongata under strong light and high temperature, and no photosynthetic “midday break” phenomenon. The carbon assimilation efficiency of U. elongatawas high. These results revealed the characteristics of heliophilous plants. Insufficient light may be a factor inhibiting the natural regeneration of U. elongata seedlings.

Key words: Ulmus elongata, light intensity, photosynthesis parameter, light response, CO2 response, chlorophyll fluorescence parameter.