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林业科学 ›› 2022, Vol. 58 ›› Issue (11): 118-126.doi: 10.11707/j.1001-7488.20221111

• 研究论文 • 上一篇    下一篇

6个白杨无性系水力效率与气体交换及生长的关系

张友静1,李月阳1,赵涵1,程玉弯1,王薇1,姜在民2,蔡靖1,3,*   

  1. 1. 西北农林科技大学林学院 杨凌 712100
    2. 西北农林科技大学生命科学学院 杨凌 712100
    3. 陕西秦岭森林生态系统国家野外科学观测研究站 杨凌 712100
  • 收稿日期:2021-04-28 出版日期:2022-11-25 发布日期:2023-03-08
  • 通讯作者: 蔡靖

Relationship between Hydraulic Efficiency and Gas Exchange and Growth of Six Poplar Clones

Youjing Zhang1,Yueyang Li1,Han Zhao1,Yuwan Cheng1,Wei Wang1,Zaimin Jiang2,Jing Cai1,3,*   

  1. 1. College of Forestry, Northwest A&F University Yangling 712100
    2. College of Life Sciences, Northwest A&F University Yangling 712100
    3. Qinling National Forest Ecosystem Research Station Yangling 712100
  • Received:2021-04-28 Online:2022-11-25 Published:2023-03-08
  • Contact: Jing Cai

摘要:

目的: 探究6个白杨无性系水力效率对气体交换和生长性能的影响,阐明水力效率与气体交换和生长的内在关系,为林木抗旱新品种选育提供理论指导。方法: 对6个白杨杂交无性系的2年生苗木,测定气体交换参数(净光合速率Anet、气孔导度gs、参比气孔导度gs-ref、水分利用效率WUE)、叶片水分状况(中午叶水势Ψmd)、水力效率(整个树冠水力效率KCL、主枝水力效率KMSL和根系水力效率KRL)、气孔特征(气孔密度SD、气孔长度SL、气孔面积指数SPI)和生长指标(地径绝对生长速率AGRD和相对生长速率RGRD)。结果: 1)6个白杨无性系的水力效率差异显著,且根、主枝及树冠的水力效率变化具有一致性,即高或低水力效率的无性系其KRLKMSLKCL均较高或较低。2)Ψmdgs的变化密切相关,在Ψmd下降至-1.1 MPa后gs急剧下降,导致Anet相应下降,而AGRD与Anet呈显著正相关。3)SL与KCLKMSLgs-ref、AGRD及RGRD显著正相关,SD与KMSLAnet及AGRD显著负相关。4)KCLKMSLgs-ref显著相关,且KCLgs-ref的相关性更强,表明较高的水力效率利于气孔开放。5)KCLKMSL呈显著正相关,两者均与AGRD及RGRD显著正相关,其中KCL与RGRD相关性更强。结论: 本研究在白杨无性系水平发现,树木各部分的水力效率相协调,根系、主枝、树冠等水平的水力效率均能反映树木运输水分的能力;水分运输效率与叶片气体交换过程密切相关,并且叶片气孔结构特征与木质部水分运输能力相匹配,高效的水分运输改善了叶片水分状况,促进了气孔开放,提高碳同化能力,从而促进生长。

关键词: 白杨, 水力效率, 气体交换, 生长速率

Abstract:

Objective: Xylem water transport is the basis of photosynthetic process and tree growth. Exploring the effect of hydraulic efficiency on gas exchange and growth performance will help to deepen the understanding of the internal relationship between hydraulic efficiency and gas exchange and growth, and provide a theoretical basis for the breeding of new drought-resistant forest varieties. Method: The 2-year-old seedlings of six poplar hybrid clonesPopulus alba 'I-101'×(P. alba×P. Glandulosa '84K') were used to measure gas exchange parameters (net photosynthetic rate Anet, stomatal conductance gs, reference stomatal conductance gs-ref, water use efficiency WUE), leaf water status (midday leaf water potential Ψmd), hydraulic efficiency (whole crown hydraulic efficiency KCL, main branch hydraulic efficiency KMSL and root hydraulic efficiency KRL), stomatal characteristics (stomatal density SD, stomatal length SL, stomatal area index SPI) and growth parameters (ground diameter absolute growth rate AGRD and relative growth rate RGRD). Results: 1) Six poplar clones showed significant difference in hydraulic efficiency, and the changes of the hydraulic efficiency of roots, main branches and crowns were consistent, that is, the clones with high or low hydraulic efficiency had higher or lower KRL, KMSL and KCL. 2) The change in Ψmd was closely related to that of gs. After Ψmd decreased to -1.1 Mpa, gs decreased sharply, resulting in a corresponding decrease in Anet. AGRD was significantly positively correlated with Anet. 3) SL was significantly positively correlated with KCL, KMSL, gs-ref, AGRD and RGRD, and SD was significantly negatively correlated with KMSL, Anet and AGRD. 4) KCL and KMSL were significantly correlated with gs-re, and KCL had a stronger correlation with gs-ref, indicating that higher hydraulic efficiency was beneficial to stomatal opening. 5) KCL was significantly positively correlated with KMSL, and KMSL was always greater than KCL (about 37.3% higher on average). KCL and KMSL were significantly positively correlated with AGRD and RGRD, among which KCL had a stronger correlation with RGRD. Conclusion: In this study, ,it is found that the hydraulic efficiency of each part of the tree is coordinated at the intraspecific clonal level, and the hydraulic efficiency of the root system, main branch, crown can reflect the ability of the tree to transport water. The water transport efficiency is closely related to the gas exchange process of leaves, and the structural characteristics of leaf stomata are coordinated with the water transport capacity. Efficient water transport improves the leaf water status, promotes stomatal opening, and improves carbon assimilation capacity, and thereby promotes growth.

Key words: poplar, hydraulic efficiency, gas exchange, growth rate

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