Knowledge Resource Center for Ecological Environment in Arid Area
| 黑河流域荒漠优势植物水分利用效率及生理调控机制研究 | |
| 其他题名 | Studies on water use efficiency and physiological regulation mechanisms of dominant desert plants in |
| 周紫鹃 | |
| 出版年 | 2014 |
| 学位类型 | 博士 |
| 导师 | 苏培玺 |
| 学位授予单位 | 中国科学院大学 |
| 中文摘要 | 发源于祁连山区的黑河流域是我国内陆河流域的典型代表，荒漠面积广袤，分布着大量的荒漠植物。本研究选择了14种在黑河流域广泛分布的荒漠植物，系统地研究了这些植物的水分生理特征及其内在的生理生化调节机制；同时，选择出4种代表性荒漠植物，深入研究了这些植物的叶片和群体水平水分利用效率。通过探索荒漠植物水分高效利用的机理，为干旱荒漠生态系统保育和绿洲生态系统管理提供理论依据和方法指导。 通过测定荒漠优势植物的δ13C值得出，在所选择的17种荒漠植物中，梭梭(Haloxylon ammodendron (C.A.Mey.) Bge.)、沙拐枣(Calligonum mongolicum Turcz.)和珍珠(Salsola passerina Bunge.)为C4植物，其他14种植物均为C3植物。选择14种在黑河中游广泛分布的荒漠植物，根据这些植物的光合途径(C3和C4)以及叶片类型(旱生叶、肉质叶和退化叶)对其进行深入分析，比较得出，肉质叶植物具有较高的相对含水量，而旱生叶植物相对含水量最低；对于不同叶片类型的植物水势来说，C4退化叶植物与C3肉质叶植物相比具有较高的水势，且差异显著(p<0.05)。通过分析14种植物的保水力证明，肉质叶植物保水力较高，在24h内失水速率普遍低于50%，而旱生叶植物失水速率较快，保水力较差。 通过测定14种荒漠植物叶片的生理生化指标发现，植物叶片的生理生化差异主要体现在不同的叶片类型上。SOD活性在退化叶植物中含量最高；相比于肉质叶和退化叶植物来说，旱生叶植物具有较高的CAT和POD活性。同时，旱生叶植物可溶性糖和可溶性蛋白的含量高于其他两种叶片类型的植物；退化叶植物中游离氨基酸的含量相对较高，平均为117.05 mg?g-1 FW；而肉质叶植物中脯氨酸含量的积累显著高于其他两种叶片类型的植物。 根据14种荒漠植物的测定指标，通过主成分分析把荒漠木本植物分为三类，分别命名为：抗旱型(退化叶植物)，包括梭梭和沙拐枣；御旱型(旱生叶植物)，包括花棒(Hedysarum scoparium Fisch. et Mey.)、柽柳(Tamarix ramosissima Ledeb.)、紫菀木(Asterothamnus alyssoides (Turcz.) Nov)、骆驼刺(Alhagi sparsifolia Shap.)、籽蒿(Artemisia sphaerocephala Krasch.)、荒漠锦鸡儿(Caragana roborovskyi Kom.)和柠条(Caragana korshinskii Kom.)；耐旱型(肉质叶植物)，包括珍珠、黄毛头(Kalidium cuspidatum (Ung.-Sternb.) Grub.)、合头草(Sympegma regelii Bunge)、红砂(Reaumuria soongorica (Pall.) Maxim.)和泡泡刺(Nitraria sphaerocarpa Maxim.)。可以看出所分类别与我们根据植物叶片类型划分的种类一致，说明植物体内的生理生化调控与植物光合途径和叶片类型紧密关联。 选择4种典型荒漠植物泡泡刺、柠条、沙拐枣和梭梭，在典型生长期7月中旬(高温强光)和8月中旬(光温适中)，系统地测定了它们的气体交换特性，结果表明，在7月中旬，除沙拐枣外，其他3种荒漠植物净光合速率(PN)的日变化均呈现出双峰曲线，而8月中旬荒漠植物的PN日变化均为单峰曲线。无论是7月还是8月中旬，梭梭和沙拐枣均具有较高的叶片和群体光合速率，且具有较高的光能利用效率，而柠条的叶片和群体光合速率在4种植物中是最低的。 比较4种荒漠植物叶片和群体水分利用效率得出，8月中旬的水分利用效率显著高于7月中旬。4种荒漠植物的群体光合速率和蒸腾速率要低于叶片水平，但是，植物的群体水分利用效率显著高于叶片水平。对7月和8月中旬叶片与群体水分利用效率进行线性回归，得出回归方程分别为：CAW = 1.6108 WUE + 0.5077 (r = 0.76, p<0.001)和 CAW = 1.0672 WUE + 1.6798 (r = 0.87, p<0.001)。通过比较植物水分利用效率与δ13C值的相关性得出，群体水平水分利用效率与δ13C值的相关性高于叶片水平，说明相比于植物的叶片水分利用效率，群体水分利用效率更能准确地反映植物的水分利用情况。 通过比较三种生境（山前荒漠、山前戈壁和中游戈壁）下红砂叶片生理生化指标与δ13C值的相关性发现，渗透调节在红砂叶片对环境的适应过程中起着重要的作用，红砂在逐步适应干旱、缺水的荒漠环境时主要通过提高体内的渗透调节物质来防止植物的脱水，从而增强其耐旱性。 C4荒漠植物水分利用效率大小的排序是，梭梭>沙拐枣>珍珠；C3荒漠植物水分利用效率大小的排序是，旱生叶植物>肉质叶植物。三种不同类型植物的用水策略生理机制是，抗旱型植物通过高的叶片水势和SOD活性调节；御旱型植物积累较多的可溶性糖和可溶性蛋白含量，其在生理生化调控上具有较高的投资以避免其光合器官的损伤，从而抵御干旱胁迫；耐旱型植物通过高的叶片持水力和脯氨酸含量来调节叶片内的渗透平衡。 |
| 英文摘要 | Heihe River Basin is a typical representation of the inland river basin which is originated from the Qilian Mountains, with vast desert areas and accommodated a large number of desert plants. In this study, we selected fourteen desert plants, which are ubiqutous in the Heihe River Basin area, and subjected to systematic study regarding the water physiological characteristics and physiological regulation mechanism of these plants. Meanwhile, we selected four representative plants with different photosynthetic pathways and leaf types to analyze the water use efficiency on leaf and canopy level. The study of the highly efficient water utilizing mechanisms in desert dominant plants could provide scientific supports and practice guidelines for the desert ecosystem conservation and the oasis ecosystem management. In the studied seventeen plants, there were three C4 plants and fourteen C3 plants based on their δ13C values. The selected fourteen desert plants were all widely distributed in the middle of Heihe River Basin. Further analyses were performed according to their photosynthetic pathways (C3 and C4) and leaves types (xerophytic leaves, fleshy leaves and degradation leaf). We found that fleshy leaves plants had higher relative water content (RWC), while xerophytic leaves plants had the lowest values; for leaf water potential (LWP), plants with C4 degradation leaf were significantly higher LWP than the plants with C3 fleshy leaves. The results of the water holding capacity indicated that the fleshy leaf plants had higher water holding capacity than that of xerophytic leaf plants, for the former, the water loss rate is generally lower than 50% within 24 h. The physiological and biochemical characteristics results of the fourteen desert species indicated that the leaf type is major impact factor on the differences of physiological and biochemical traits. The species with degradation leaf had the highest SOD activities, while the species with xerophytic leaf had higher CAT and POD activities than that of the other two leaf types. For osmotic adjustment, plants with xerophytic leaf also had higher soluble sugar and soluble protein contents; degradation leaf plants had higher free amino acids contents, with an average of 117.05 mg?g-1 FW, while fleshy leaf plants accumulation higher proline content than that of the other leaf type species. The principal component analysis indicated that the desert woody plants could be roughly divided into three types, named as drought resistance (degradation leaf), including H. ammodendron and C. mongolicum; drought avoidance (xerophytes leaf), including H. scoparium, T. ramosissima, A. sparsifolia, A. alyssoides, A. sphaerocephala, C. roborovskyi, C. korshinskii; drought tolerance (fleshy leaf), including S. passerina, K. cuspidatum, S. regelii, R. soongorica and N. sphaerocarpa, respectively. We found that all the three groups were consistent with our hypothesis classification, suggesting that there are some relationships between physiological regulation and leaf type. Desert plants with different leaf types is the result of long-term adaption to the drought environment. Four typical desert plants, N. sphaerocarpa, C. korshinskii, H. ammodendron and C. mongolicum were subjected to the measurement of their gas exchange characteristics on mid-July (high temperature and strong light) and mid-August (comfortable light and temperature). In mid-July, with exception of C. mongolicum, diurnal changes of net photosynthetic rate (PN) of the other three desert plants showed a bimodal pattern, while in mid-August, the diurnal changes of PN were all unimodal pattern. Both in mid-July or mid-August, H. ammodendron and C. mongolicum had the highset PN and canopy apparent photosynthetic rate (CAP) values, and also had higher light utilization efficiency, while C. korshinskii had the lowest PN and CAP values. With comparasion of the leaf water use efficiency (WUE) and canopy water use efficiency (CAW) we found tha |
| 中文关键词 | 荒漠植物 ; 光合途径 ; 叶片类型 ; 水分利用效率 ; 群体光合作用 ; 生理调控 |
| 英文关键词 | desert plants photosynthetic pathway leaf types water use efficiency canopy apparent photosynthetic rate physiological regulation |
| 语种 | 中文 |
| 国家 | 中国 |
| 来源学科分类 | 生态学 |
| 来源机构 | 中国科学院西北生态环境资源研究院 |
| 资源类型 | 学位论文 |
| 条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/287377 |
| 推荐引用方式 GB/T 7714 | 周紫鹃. 黑河流域荒漠优势植物水分利用效率及生理调控机制研究[D]. 中国科学院大学,2014. |
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