南京林业大学学报(自然科学版) ›› 2021, Vol. 45 ›› Issue (2): 69-76.doi: 10.12302/j.issn.1000-2006.201909045

• 研究论文 • 上一篇    下一篇

夏季淹水胁迫对北美枫香苗木叶色及光合荧光特性的影响

仲磊1,2(), 张焕朝1,*(), 范俊俊3, 张丹丹4, 江皓1, 张往祥1   

  1. 1.南京林业大学林学院,南方现代林业协同创新中心,江苏 南京 210037
    2.江苏省林木种苗管理站,江苏 南京 210036
    3.金陵科技学院园艺园林学院,江苏 南京 211169
    4.金埔园林股份有限公司,江苏 南京 211100
  • 收稿日期:2019-09-23 接受日期:2020-04-08 出版日期:2021-03-30 发布日期:2021-04-09
  • 通讯作者: 张焕朝
  • 基金资助:
    国家重点研发计划(2015BAD07B01)

Effects of flooding stress on leaf color and photosynthetic fluorescence characteristics of Liquidambar styraciflua cutting seedlings in summer

ZHONG Lei1,2(), ZHANG Huanchao1,*(), FAN Junjun3, ZHANG Dandan4, JIANG Hao1, ZHANG Wangxiang1   

  1. 1. Co-Innovation Center for the Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China
    2. Jiangsu Province Forest Seedling Management Station, Nanjing 210036, China
    3. College of Horticulture, Jinling Institute of Technology, Nanjing 211169, China
    4. Jinpu Landscape Co., Ltd., Nanjing 211100, China
  • Received:2019-09-23 Accepted:2020-04-08 Online:2021-03-30 Published:2021-04-09
  • Contact: ZHANG Huanchao

摘要:

【目的】评价北美枫香(Liquidambar styraciflua)耐涝性,并从叶色与色素、光合荧光等生理指标间的协同性分析其耐涝机理,为沿海和涝害地区耐水湿观赏树种的筛选提供参考。【方法】模拟中国南方洪水季节性发生的特点,在夏季高温期间,对北美枫香1年生扦插苗进行60 d的户外盆栽淹水处理,分析其在淹水过程中生长、叶色(色彩参数与色素比例)及光合特征[净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci)]、叶绿素荧光动力学特性[单位叶面积反应中心数(NRC/CSm)单位叶面积热耗散的能量(EDIo/CSm)、PSⅡ捕获能量从QA传递到QB的效率(ψO)、电子传递的量子比率(φEo)、受体侧末端电子受体的量子产额(φRo)、综合性能指数(Itotal)]的动态变化趋势,并根据各指标峰谷值出现时间分析指标间的协同性。【结果】①淹水持续60 d并未对北美枫香的生长产生抑制作用,苗木的成活率能达到90%以上。②叶色参数结果显示,随着淹水时间的延长,色调角h值呈现显著下降趋势,40 d后,叶片由绿色相域转变为红色相域(h<90°)。③叶片色素相对含量比值结果显示,随着淹水时间的延长,处理的叶片叶绿素与花青素及类胡萝卜素相对含量的比值[Chl/(Anth+Car)]呈现下降趋势。20 d后,处理Chl/(Anth+Car)的值显著低于对照(CK),在40 d后,Chl/(Anth+Car)的值小于1(胡萝卜素和花青素相对含量占据主要地位),这与叶片外观色彩参数变化表现出同步性。④处理与CK叶片光合气体交换参数变化趋势整体相似,PnCi均呈现下降—上升—下降趋势,TrGs均呈现下降趋势;在淹水初期(0~20 d)处理与CK各光合参数值差异不显著,但在淹水中后期(20 d后),处理各参数值显著低于CK,且二者差异整体呈现增大趋势。⑤光响应曲线特征表明,处理在各光强下的Pn显著低于CK,且随着淹水时间的延长,处理与CK的Pn差值越大,表现出较低的光能利用率。⑥叶绿素荧光动力学参数表明,淹水30 d后,叶片反应中心数目(NRC/CSm)和光系统PSⅡ向PSⅠ的电子传递能力(Ψo、$φ_{Ro}$和$φ_{Ro}$)均显著下降,叶片的热耗散($E_{\text{DIo/CS m}}$)显著上升,最终导致PSⅡ综合性能指数显著下降。【结论】北美枫香具有较强的短期耐水淹能力,尤其在淹水20 d内,各指标均优于CK;北美枫香主要通过增加叶片热耗散以及调节光合色素含量权重来减少激发能和过剩激发能产生的伤害,从而降低涝害程度;净光合速率、叶片色素比值及荧光参数之间存在协同性,各参数拐点出现的时间呈节律性变化,分别为20、30 及40 d,其中光合参数反应最为灵敏。

关键词: 淹水胁迫, 北美枫香, 色彩空间, 光合特征, 叶绿素荧光, 协同性, 夏季

Abstract:

【Objective】The purpose of this experiment is to estimate the flooding resistance of Liquidambar styraciflua and to analyze the flooding resistance mechanism, combined with the synergy of leaf color, leaf pigments and photosynthetic fluorescence characteristics.【Method】The dynamic trends of growth, leaf color (color parameters and pigment ratio), photosynthetic characteristics [net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), intercellular CO2 concentration (Ci)]; and chlorophyll dynamic fluorescence characteristics [leaf reaction center number (NRC/CSm), efficiency by trapped exciton (Ψo), quantum ratio for electron transfer (φRo), quantum yield of electron acceptor at the end of acceptor side (φEo), dissipation (EDIo/CSm), and performance index (Itotal)] of one-year-old cuttings of L. styraciflua were analyzed under 60 days of flooding treatment outdoors in summer at high temperatures. 【Result】①The growth of L. styraciflua was not inhibited by flooding treatment after 60 days, and the survival rate of cuttings was still up to 90%. ② The leaf color parameter (h) decreased significantly with prolongation of flooding. After 40 days, the color of the leaves changed from green to red (h< 90°). ③ The relative content ratio of chlorophyll to anthocyanin and carotenoid [Chl/(Anth+Car)] showed a significant decreasing trend after 20 days. After 40 days, the ratio of pigments was less than 1. The change in pigments was synchronized with that of the leaf color parameters. ④ The trend of photosynthetic gas exchange parameters of treated cuttings was similar to that of the control. Both Pn and Ci showed downward-upward-downward trend, while Tr and Gs showed downward trend. In the early stage of flooding (0-20 days), there was no significant difference between the treatment and control groups, but in the late stage of flooding (20 days later), the values of each parameter were significantly lower than that of the control, and the difference between them increased. ⑤ The characteristics of the light response curve showed that the Pn of the treatment was significantly lower than that of the control, and with flooding prolongation, the difference in Pn between the treatment and control was larger than that of the control, which indicated that the light utilization rate of the treatment was lower. ⑥ With prolonged flooding (after 30 days of flooding), the number of leaf reaction centers (NRC/CSm) and the energy of electronic transmission from PSII to PSI (Ψo, φRo and φEo) were significantly decreased, and the EDIo/CSm was significantly increased, which resulted in a decrease in the performance index (Itotal). 【Conclusion】The L. styraciflua has strong short-term flooding tolerance. All indexes of treatments were better than those of the control in the first 20 days. This was because of the reduction in excitation energy generation and excess excitation energy damage by increasing the heat dissipation of leaves, thereby adjusting the weight of the photosynthetic pigment content. There was synergism among net photosynthetic rate, leaf pigment ratio and fluorescence parameters, and the time of inflection of each parameter changed rhythmically, that is, 20, 30 and 40 days, respectively. The photosynthetic parameter response was the most sensitive.

Key words: flooding stress, Liquidambar styraciflua, color space, characterization of photosynthesis, chlorophyll fluorescence, synergy, summer

中图分类号: