南京林业大学学报(自然科学版) ›› 2023, Vol. 47 ›› Issue (1): 83-91.doi: 10.12302/j.issn.1000-2006.202106018

• 研究论文 • 上一篇    下一篇

水曲柳幼苗水力结构和光合生理对光强梯度变化的耦合响应

孔鑫1,2(), 王爱英3(), 郝广友1,*(), 宁秋蕊1,2, 王淼1,2, 殷笑寒1,4, 周永姣1,2   

  1. 1.中国科学院沈阳应用生态研究所森林生态与管理重点实验室,辽宁 沈阳 110016
    2.中国科学院大学,北京 100049
    3.辽宁省城市有害生物治理与生态安全重点实验室,沈阳大学生命科学与工程学院,辽宁 沈阳 110044
  • 收稿日期:2021-06-11 接受日期:2022-04-12 出版日期:2023-01-30 发布日期:2023-02-01
  • 通讯作者: 郝广友
  • 作者简介:孔鑫(3160563672@qq.com),负责论文撰写及数据分析;|王爱英(aiyingwqepq@163.com),副教授,负责试验设计与论文修改。
  • 基金资助:
    国家自然科学基金项目(31901284);国家自然科学基金项目(31870593);国家自然科学基金项目(31722013);辽宁省“兴辽英才计划”项目(XLYC1807204);沈阳市中青年科技创新人才项目(RC190143)

Coordinated responses of hydraulic architecture and photosynthetic characteristics in Fraxinus mandschurica seedlings to change of light intensity irradiance

KONG Xin1,2(), WANG Aiying3(), HAO Guangyou1,*(), NING Qiurui1,2, WANG Miao1,2, YIN Xiaohan1,4, ZHOU Yongjiao1,2   

  1. 1. Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. Liaoning Key Laboratory of Urban Pest Management and Biosafety, School of Life Science and Engineering, Shenyang University, Shenyang 110044, China
    4. Forest Ecology and Forest Management Group,Wageningen University, Wageningen 476700, Netherlands
    4. Forest Ecology and Forest Management Group, Wageningen University, Wageningen 476700, Netherlands
  • Received:2021-06-11 Accepted:2022-04-12 Online:2023-01-30 Published:2023-02-01
  • Contact: HAO Guangyou

摘要: 【目的】 研究水曲柳(Fraxinus mandschurica)幼苗对不同光照强度的响应及适应机理,为育苗造林和林下天然更新研究提供参考。【方法】 以2年生盆栽水曲柳幼苗为材料进行不同光照处理,1年后测定幼苗在4种强度日光处理(相对光强100%、60%、30%和15%)下的生长、光合生理和水力性状等指标。【结果】 遮阴处理显著影响了水曲柳幼苗的生长、光合和水分生理特性。与60%和30%相对光强处理相比,100%相对光强下水曲柳具有更高的气孔导度(Gs)、净光合速率(Pn)、根系水力导度(Kroot)、地上部分水力导度(Kshoot)和整株水力导度(Kplant)。随光照强度的减弱,水曲柳的生长速率显著降低,根生物量占比(RMR)减少,最大净光合速率(Pn,max)、光补偿点(LCP)和光饱和点(LSP)降低,而茎、叶生物量占比(SMRLMR)以及表观量子效率(AQY)增加;枝条木质部解剖结构在不同光照处理下存在显著差异,相对光强100%处理时的导管密度显著高于相对光强30%和60%处理,而导管直径显著低于30%和60%处理。【结论】 水曲柳幼苗通过调节形态、光合和水分生理特性来适应一定程度的弱光环境,但总体上对光强有较高的需求。水曲柳的光合和水力性状随光照强度的改变都具有较大的可塑性,二者对光照强度梯度变化的响应存在显著耦合关系。这些性状的可塑性响应有利于提高水曲柳幼苗在异质性光环境下的生存适合度,对于其更新阶段在林下不同光照条件下的生存有重要意义。

关键词: 水曲柳幼苗, 耐阴性, 光照强度, 表型可塑性, 光合特性, 水力性状

Abstract:

【Objective】 This study aims to explore the response and adaptive mechanisms of Fraxinus mandschurica to different light intensities, to provide a basis for reforestation and forest regeneration. 【Method】 Two-year-old potted Fraxinus mandschurica seedlings were grown under four different light treatments (100%, 60%, 30%, and 15% of full sunlight). The photosynthetic and hydraulic characteristics of the seedlings were then measured. 【Result】 Shading treatments significantly affected the growth, photosynthesis, and hydraulics of Fraxinus mandschurica seedlings. Seedlings had a higher stomatal conductance (Gs), net photosynthetic rate (Pn), hydraulic conductance of root (Kroot), shoot (Kshoot), and whole plant (Kplant) under 100% relative light intensity than under 60% and 30% relative light intensities. With a decrease in light intensity, the growth rate, ratio of root mass (RMR), maximum net photosynthetic rate (Pn,max), light saturation point (LSP), and light compensation point (LCP) decreased, while the ratio of stem mass (SMR) and leaf mass (LMR) and apparent quantum yield (AQY) increased. Xylem anatomies were significantly different among the three light treatments. For example, the vessel density was significantly higher in the 100% than in the 30% and 60% relative light intensities, but the vessel diameter was significantly lower in the 100% than in the 30% and 60% light treatments. 【Conclusion】 Even though Fraxinus mandschurica was able to slightly adapt to low-light conditions by adjusting its morphology, photosynthesis, and hydraulic characteristics, it mostly had a high demand for light during its seedling stage. There was a coupling between the hydraulic architecture and photosynthetic characteristics in response to changes in the light intensity. The photosynthetic and hydraulic characteristics of Fraxinus mandschurica seedlings showed relatively larger plasticity with changes in light treatment. Relatively larger plastic adjustments of functional traits can contribute to greater fitness in heterogeneous light environments of the forest understory, which has great significance for the regeneration of Fraxinus mandshurica seedlings in natural forests.

Key words: Fraxinus mandschurica seedling, shade tolerance, light intensity, phenotypic plasticity, photosynthetic characteristic, hydraulic trait

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