【摘要】：胡楊作為優(yōu)異的樹種,在沙漠中廣泛生存生長,耐旱性非常強,是抗擊沙化最有利的樹種。本文對胡楊個體發(fā)育過程中不同徑階(時間)、同一徑階不同高度(空間層次)的胡楊異形葉形態(tài)變化、光合水分生理和生理生化特性的時空變化特征進(jìn)行了研究,以揭示胡楊個體發(fā)育過程的生長適應(yīng)機制,得出如下結(jié)論:(1)胡楊異形葉形態(tài)特征與個體發(fā)育階段的關(guān)系。研究結(jié)果表明,隨著徑階的增大,葉片平均寬度、平均葉面積呈逐步增大趨勢,葉形指數(shù)和葉長度呈逐步減小趨勢;各徑階隨著采樣高度的增加,胡楊葉片平均寬度、葉面積逐漸增加,而葉片長度和葉形指數(shù)則逐漸減小。隨著徑階的增大,葉干重和比葉重逐步增大;各徑階隨著采樣高度的增加(由基部向頂部),葉片的葉干重、比葉重也在逐漸增加。相關(guān)性分析也表明,胡楊異形葉的葉長和葉形指數(shù)隨著采樣高度的增加而減小,葉寬、葉面積、干重和比葉重隨著采樣高度的增加而增大。(2)胡楊異形葉光合水分生理特征與個體發(fā)育階段的關(guān)系。各徑階均表現(xiàn)出隨著采樣高度的增加,葉片凈光合速率、蒸騰速率、氣孔導(dǎo)度和碳同位素值呈逐漸增加趨勢,葉片胞間CO2濃度則呈逐步下降趨勢。相關(guān)性分析表明,葉片的凈光合速率、胞間CO2濃度和氣孔導(dǎo)度與葉片所在樹的高度密切相關(guān),即,葉片凈光合速率、氣孔導(dǎo)度與葉片所處樹的高度呈顯著正相關(guān),胞間CO2濃度與葉片所處樹的高度呈顯著負(fù)相關(guān),碳同位素值與凈光合速率的相關(guān)系數(shù)為0.56,呈極顯著正相關(guān),與氣孔導(dǎo)度的相關(guān)系數(shù)為-0.55,呈極顯著負(fù)相關(guān)。同時葉片的凈光合速率和氣孔導(dǎo)度變化與異形葉形態(tài)、葉形指數(shù)變化密切相關(guān),而葉片胞間CO2濃度僅與采樣高度變化有密切關(guān)系。(3)胡楊異形葉生理生化特性與個體發(fā)育階段的關(guān)系。葉片可溶性糖含量隨著徑階的增大呈現(xiàn)逐步增大趨勢,葉片可溶性蛋白含量隨葉片所在樹的高度增加而逐步降低的趨勢。各徑階均表現(xiàn)出葉片脯氨酸和丙二醛含量隨葉片所在樹的高度增加而逐步增高的趨勢。葉片可溶性蛋白質(zhì)、脯氨酸含量變化與葉片所在樹的高度變化有密切關(guān)系;即葉片脯氨酸含量隨葉寬和葉面積的增大而升高,葉片可溶性蛋白質(zhì)、脯氨酸含量變化與異形葉形態(tài)及異形葉所在樹的高度變化有密切關(guān)系,這意味著胡楊的闊卵形葉或卵形葉要比條形葉或披針形葉有著更強的抗逆性。
[Abstract]:Populus euphratica, as an excellent tree species, exists widely in the desert and has strong drought tolerance, which is the most favorable tree species to resist desertification. In this paper, the temporal and spatial changes of the special-shaped leaves of Populus euphratica with different diameters (time) and different height (spatial level) during the development of Populus euphratica were studied, and the temporal and spatial changes of physiological and physiological characteristics of photosynthetic water were studied. In order to reveal the growth and adaptation mechanism of Populus euphratica, the following conclusions are drawn: (1) the relationship between the morphological characteristics of special-shaped leaves of Populus euphratica and the stage of ontogeny. The results showed that with the increase of diameter order, the average leaf width and mean leaf area increased gradually, leaf shape index and leaf length gradually decreased, and the average leaf width of Populus euphratica increased with the increase of sampling height. Leaf area increased gradually, while leaf length and leaf shape index decreased gradually. With the increase of diameter order, the leaf dry weight and specific Ye Zhong increased gradually, and the leaf dry weight of leaf increased gradually with the increase of sampling height (from base to top). Correlation analysis also showed that leaf length and leaf shape index of P. euphratica decreased with the increase of sampling height, leaf width and leaf area. The dry weight and specific Ye Zhong increased with the increase of sampling height. (2) the relationship between physiological characteristics of photosynthesis water and ontogeny stage of P. euphratica leaves. With the increase of sampling height, the net photosynthetic rate, transpiration rate, stomatal conductance and carbon isotope value increased gradually, and the intercellular CO _ 2 concentration decreased gradually. Correlation analysis showed that the net photosynthetic rate, intercellular CO _ 2 concentration and stomatal conductance were closely related to the height of the tree in which the leaves were located, that is, the leaf net photosynthetic rate and stomatal conductance were significantly positively correlated with the height of the tree in which the leaves were located. The correlation coefficient of carbon isotope value and net photosynthetic rate was 0.56, and the correlation coefficient between intercellular CO _ 2 concentration and stomatal conductance was -0.55, which was extremely significant negative correlation. At the same time, the changes of net photosynthetic rate and stomatal conductance of leaves were closely related to the changes of special-shaped leaf morphology and leaf shape index. However, the intercellular CO _ 2 concentration in leaves was only closely related to the variation of sampling height. (3) the relationship between physiological and biochemical characteristics of P. euphratica leaves and the ontogeny stage. The content of soluble sugar in leaves increased gradually with the increase of diameter order, and the content of soluble protein in leaves decreased gradually with the height of the tree in which the leaves were located. The content of proline and malondialdehyde in leaves increased with the height of tree. The changes of leaf soluble protein and proline content were closely related to the height of the tree, that is, the content of proline increased with the increase of leaf width and leaf area, and the content of leaf soluble protein increased with the increase of leaf width and leaf area. The change of proline content was closely related to the shape of the special-shaped leaves and the height of the trees in which the special-shaped leaves were located, which meant that the broad-ovate or ovate-shaped leaves of Populus euphratica were more resistant to stress than strip or lanceolate leaves.
【學(xué)位授予單位】：塔里木大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S792.11

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本文編號：2122546