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生态学杂志

• 研究报告 • 上一篇    下一篇

光强对杂交泡桐光合生理和荧光特性的影响

王楠,李芳东,叶金山**   

  1. (中国林业科学研究院国家林业局泡桐研究开发中心, 郑州 450003)
  • 出版日期:2015-11-10 发布日期:2015-11-10

Effects of light intensity on photosynthetic physiology and chlorophyll fluorescence characteristics of hybrid Paulownia.

WANG Nan, LI Fang-dong, YE Jin-shan**   

  1. (Paulownia Research and Development Center of State Forestry Administration, Chinese Academy of Forestry, Zhengzhou 450003, China)
  • Online:2015-11-10 Published:2015-11-10

摘要: 以杂交泡桐毛白33(即TF33)及其回交一代(BC-1(194)和BC-1(192))为材料,通过人工模拟旷地、林窗和林下3种光环境(分别为全光照L0、50%全光照L1、25%全光照L2),比较了不同光强下泡桐回交一代及其亲本TF33叶片的光合能力和叶绿素荧光特性的差异。结果显示:(1)遮荫后杂交泡桐净光合速率(Pn)日变化曲线由“双峰”型变为“单峰”型,日平均Pn随遮荫程度增加显著降低(P<0.05)。L0条件下,BC-1(194)和BC-1(192)的日平均Pn未表现出杂种优势;L1条件下,BC-1(192)和BC-1(194)的日平均Pn杂种优势率(RH)分别为2.23%和3.67%;L2条件下,BC-1(192)的日平均Pn高于TF33,但差异不显著,BC-1(194)则表现为杂种劣势。(2)L0条件下,TF33的最大净光合速率(Pmax)和光饱和点(LSP)最大,光补偿点(LCP)和暗呼吸速率(Rd)最小;L1条件下,BC-1(192)的Pmax、LSPAQY最大,LCP和Rd最小;L2条件下,虽然BC-1(194)和BC-1(192)的Pmax低于TF33,但其LCPRd值也低于TF33。(3)L0条件下,TF33、BC-1(194)和BC-1(192)各荧光参数差异不显著;L1条件下,3个无性系的qPqN差异显著,BC-1(192)的热耗散最弱,光合能力最强;L2条件下,BC-1(192)和TF33的qP差异不显著,BC-1(194)与TF33差异显著,BC-1(192)的Fv/FmF0ETR与TF33、BC-1(194)差异显著(P<0.05)。结果表明,TF33、BC-1(194)和BC-1(192)虽均对弱光有一定的调节适应机制,但在全光照下生长最为适宜,遮荫使植株的光合能力显著降低,光照不足成为其生长的决定性限制因子。在低光照(L1)条件下,BC-1(194)和BC-1(192)较其亲本TF33有光合优势。

关键词: 气候变化, BioMod2, 人参, 组合模型

Abstract: The purpose of this experiment was to compare the differences of leaf photosynthetic capacity and chlorophyll fluorescence characteristics between Paulownia backcross optimal plants (including BC-1(194) and BC-1(192)) and their parent TF33. Three light levels \[100% (L0), 50% (L1) and 25% (L2) of natural sunlight\] were conducted to simulate the light conditions of forest opening, forest gap and understory, respectively. The results showed that: (1) The diurnal variation of net photosynthetic rate (Pn) changed from bimodal pattern to unimodal type curve after shading, and the average daily Pn decreased significantly with increase of shade degrees (P<0.05). Pn of BC-1(194) and BC-1(192) showed no significant advantage under L0. But the Pn transgressive heterosis of BC-1(192) and BC-1(194) were respectively 2.23% and 3.67% under L1. BC-1(192) had no remarkable advantage in Pn compared to TF33, while BC-1(194) showed hybrid weakness under L2. (2) TF33 had the highest maximum net photosynthetic rate (Pmax) and light saturation point (LSP), but the lowest light compensation point (LCP) and dark respiration rate (Rd) under L0 among three clones. Under the condition of L1, Pmax, LSP and apparent quantum yield value (AQY) of BC-1(192) were the highest, while LCP and Rd were the lowest. Although Pmax of BC-1(194) and BC-1(192) in L2 were lower than that of TF33, LCP and Rd were lower, too. (3) The differences in fluorescence parameters were not significant among TF33, BC-1(194) and BC-1(192) under L0. qP and qN were significantly different among three clones and BC-1(192) had the weakest heat dissipation but strongest photosynthetic capacity under L1. BC-1(192) had no significant difference in qP with TF33, while BC-1(194) had significant difference with TF33 under L2. At the same time, BC-1(192) had significant difference in Fv/Fm, F0, ETR with BC-1(194) and TF33 (P<0.05). Our results indicated that TF33, BC-1(194) and BC-1(192) had internal regulatory mechanisms for responding to weak light to a certain extent, but it is most appropriate for growth under full light and their photosynthetic capacity decreased with the increase of shading degree. Inadequate light could become a decisive limiting factor for the growth of hybrid Paulownia. BC-1(194) and BC-1(192) had photosynthetic superiority compared with their parent TF33 in the low light condition of L1.

Key words: BioMod2, climate change, ensemble model, Panax ginseng