KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 凝结水对胡杨幼苗生长和水分利用的影响 | |
| Alternative Title | Effects of Dew on Growth and Water Utilization of Populus euphratica Seedlings |
| 张颖 | |
| Subtype | 硕士 |
| Thesis Advisor | 郝兴明 |
| 2019-06-30 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 理学硕士 |
| Keyword | 凝结水 胡杨幼苗 生理生态响应 稳定同位素示踪技术 Dew Populus euphratica seedlings Physiological and ecological response Stable isotope tracer |
| Abstract | 在干旱、半干旱地区，凝结水作为植物水分来源的重要补充， 对植物的生长和水分利用具有重要意义。然而，在干旱环境下植物叶片是否能够直接吸收利用凝结水目前还缺乏直接的证据。本研究通过双因子控制实验和氢同位素 D 示踪实验来揭示胡杨幼苗生长特性和叶片荧光特征对不同凝结水量的响应，以及胡杨叶片吸收并利用凝结水的过程。实验设计为三种土壤水分梯度， 水分充足80%~85%（s0）、 轻度干旱 60%~65%（s1）、中度干旱 40%~45%（s2），凝结水处理设计为较多凝结水（w2）， 适量凝结水（w1） 和无凝结水（w0）。研究结果表明： 不同土壤水分条件下，胡杨幼苗叶片生物量和总生物量在不同凝结水处理间存在显著差异（p < 0.05）。同时，幼苗的株高和根表面积对不同凝结水量处理均也存在显著差异（p < 0.05）。适量凝结水处理可提高叶片实际光量子产量（ФPSII）、最大光量子产量（Fv/Fm）和相对电子传递速率（ETR）。稳定同位素 D 示踪结果表明：不同干旱胁迫下，凝结水处理过的胡杨幼苗叶片、枝条、茎、根和土壤水中??含量都显著高于未处理组（P < 0.05），其中又以土壤中??含量最高，叶片次之，枝条和茎最低。相对于水分充足和轻度干旱胁迫，中度干旱胁迫下凝结水对胡杨幼苗体内水分和土壤水分的贡献率最高。这表明胡杨幼苗叶片不仅能直接吸收凝结水，而且可以通过体内水分运输通道把大量水分转移到其他部位以及土壤中。综上所述，凝结水不仅能够促进干旱胁迫下胡杨幼苗的生长和发育，而且可以显著提高中度干旱条件下幼苗的叶片荧光参数（ФPSII， ETR）。 胡杨幼苗叶片不但能够吸收凝结水， 而且可以将其转移到植物体内，并转存到土壤中。 显然，胡杨叶片对凝结水的吸收和分配改善了生长季的水分条件，是胡杨应对短期干旱和土壤水分缺乏的一种重要生存策略。 |
| Other Abstract | Dew is an important source of plant water and also plays an important role in theregional water balance and ecosystem stability in semi-arid and arid regions. However,there is still a lack of direct evidence that the foliage of desert riparian forest plantscan absorb and use dew directly. Therefore, we designed a two-factor control andstable isotope experiment to reveal the physiological and ecological response ofPopulus euphratica seedlings to three different amounts of dew (no dew (0 mm), anappropriate amount of dew (0.3 mm), and a higher level of dew (0.7 mm)) under threedifferent soil water contents (the soil relative water content for sufficient (80%~85%),mild (60%~65%), and moderate drought were (40%~45%)).The results indicated that the leaf biomass, total biomass, height growth, and thesurface area of roots differed significantly between different amounts of dew underdifferent levels of drought stress. The presence of dew improved the quantum yield ofphotosystem II (ФPSII), the maximum photon quantum yield (Fv/Fm), and the relativeelectron transfer rate (ETR) of leaves. The stable isotope tracing experiments showedthat under different levels of drought stress, the Delta deuterium (??) value of leaves,branches, stems, roots, and soil water of Populus euphratica seedlings in the dewtreatment was significantly higher than that in the untreated group (p < 0.05). Inaddition, the ?? value of soil water was the highest, followed by leaves, branches, andstems. Populus euphratica seedlings can absorb dew by direct foliar uptake and canredistribute the dew among plant organs and even the soil. Compared with thewater-sufficient and mild drought stress, the dew under moderate drought stress hadthe highest contribution rate to the water and soil moisture of Populus euphraticaseedlings.Dew treatments significantly promoted the growth and development of Populuseuphratica seedlings, especially under the soil moisture sufficient condition.Moreover, under moderate drought, dew treatment can significantly improve thefluorescence parameters (ФPSII, ETR) of leaves of Populus euphratica seedlings. Theleaves of Populus euphratica seedlings can not only absorb dew, but also transfer it toplants and to the soil. Obviously, the absorption and distribution of dew on leaves ofPopulus euphratica improved the soil moisture condition in the growing season andare important survival strategies for Populus euphratica to adjust to short-term drought. |
| Subject Area | 自然地理学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/15350 |
| Collection | 中国科学院新疆生态与地理研究所 研究系统 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 张颖. 凝结水对胡杨幼苗生长和水分利用的影响[D]. 北京. 中国科学院大学,2019. |
| Files in This Item: | There are no files associated with this item. | |||||
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment