四种木本植物对冬涝夏旱的适应性比较研究

发布时间：2018-03-05 21:38

本文选题：三峡库区消落带　切入点：木本植物　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：三峡水库在发电、防洪、通航等领域做出了卓越的贡献,但也造成了水土流失等一系列生态问题。植被修复是治理三峡库区生态问题的重要途径,其关键在于筛选适生树种。本文以中山杉、水杉、秋华柳、桑树这四种适应性较强的植物为研究对象,通过模拟三峡库区消落带胁迫特点进行实验,研究四种植物耐“水淹”、“干旱”和“水淹-干旱”胁迫的形态学、生理生化反应及其相关性,并综合比较四种植物耐水分胁迫能力的强弱,为三峡库区植物修复树种选择及种植海拔范围提供了一定理论依据。经实地调查发现,中山杉是三峡库区优良的植被修复待选物种,适应库区复杂的环境,能在海拔168-175米消落带存活下来,深入探讨其对“水淹-干旱”交替胁迫的适应能力,具有较高的科研和实际价值。本论文主要分为水淹胁迫和干旱胁迫两阶段试验,研究四种植物耐“水淹”、“干旱”和“水淹-干旱”胁迫能力。第一阶段水淹胁迫试验设置全淹组和对照组。经过40天的冬季休眠期水淹处理后,四种植物发生不同的形态学适应变化:中山杉和水杉叶片表面形成气膜;中山杉产生明显的不定根;中山杉、水杉、秋华柳全淹组叶片比叶重较对照组降低;这些变化利于气体交换,增强植株对水淹胁迫的耐受能力。水淹胁迫后四种植物光合色素产生不同的适应性变化。四种植物全淹组叶绿素显著低于对照组,说明冬季水淹胁迫后植物新生叶片的叶绿素合成受到影响;中山杉、水杉和桑树全淹组叶片叶绿素a/b的值均较对照组有所降低,叶绿素a/b的值降低有利于植物维持相对正常的光合效率。全淹组四种植物体内丙二醛(MDA)含量均较对照组增加,而根系活力均下降,表明四种植物在冬季休眠期水淹胁迫后受到了一定程度的损伤;全淹组四种植物体内超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性都较对照组显著增高,抑制了体内MDA积累的速度,属于植物应对水淹胁迫的积极响应,一定程度上维持了植物在水淹胁迫后正常的生理生化行为。四种植物全淹组脯氨酸、可溶性糖、可溶性蛋白含量较对照组增加,帮助植物在水淹胁迫后维持较高的吸水和保水能力,维持植物正常的氮代谢过程;但全淹组秋华柳可溶性糖含量低于对照组,全淹组桑树体内可溶性蛋白含量低于对照组,具体原因待进一步研究。第二阶段干旱胁迫试验分为全程对照组(CC组)、前期正常处理后期干旱胁迫处理(CD组)和前期水淹处理后期干旱处理(FD组)。待经冬季休眠期水淹胁迫处理的四种植株生长发育完全恢复后,于2016年7月5日开始为期20天的干旱胁迫处理。四种植物经干旱胁迫处理后,CD组叶绿素含量和根系活力均显著小于CC组,四种植物CD组丙二醛含量均显著大于CC组,说明四种植物在干旱胁迫下光合色素发生降解或合成过程受阻,根系活力受到胁迫影响,细胞脂膜受到损伤导致丙二醛含量增加。四种植物CD组叶绿素a/b的值均较CC组降低,说明植物干旱胁迫下能调整叶绿素a/b的值来维持相对正常的光合效率。四种植物CD组抗氧化酶活性和渗透调节物质含量均大于CC组,说明四种植物均能通过调整体内抗氧化酶活性和渗透调节物质含量来适应干旱胁迫。四种植物能采取生理生化积极响应以应对干旱胁迫,具有一定耐旱能力。四种植物FD组叶绿素含量、叶绿素a/b的值均较CC组有所降低,水杉降幅最大;四种植物FD组与CC组相比MDA都显著提高,而根系活力均显著降低;FD组抗氧化酶活性和渗透调节物质含量均大于CC组;这些变化说明四种植物均能通过调整体内光合色素、抗氧化酶活性和渗透调节物质含量来适应“水淹-干旱”交替胁迫,但适应能力具有差异,可能是各自特殊的生理生化机制所致。经过“水淹-干旱”胁迫后,中山杉体内MDA与SOD、POD、脯氨酸呈显著正相关性;说明中山杉主要依靠这三种物质来抑制MDA积累。水杉体内MDA与CAT、APX呈显著正相关性,同时MDA与根系活力呈显著负相关性,说明水杉主要依靠CAT、APX活性增加来抑制MDA积累,水杉MDA含量增加会对根系活力造成影响。秋华柳MDA含量与CAT、APX、可溶性糖呈显著正相关性,说明秋华柳主要依靠CAT、APX、可溶性糖来抑制MDA增长;同时MDA与根系活力呈显著负相关性,说明秋华柳体内MDA含量增加影响了根系活力。桑树MDA含量与SOD、可溶性蛋白呈显著正相关性,说明桑树体内主要依靠SOD和可溶性蛋白来抑制MDA积累速度。使用隶属函数法分析两阶段结果表明,四种植物耐淹能力强弱依次为:秋华柳中山杉水杉桑树;四种植物耐旱能力强弱依次为:桑树水杉中山杉秋华柳;四种植物耐“水淹-干旱”交替胁迫能力依次为:秋华柳中山杉桑树水杉。四种植物是优良的三峡库区生态修复备选树种,能通过形态学、抗氧化酶系统、渗透调节系统的调控来适应三峡库区消落带类冬涝夏淹胁迫,具有较高生态价值和经济价值。
[Abstract]:The Three Gorges Reservoir in flood control, power generation, has made outstanding contributions to the navigation and other fields, but also caused a series of ecological problems such as soil and water loss. The vegetation restoration is an important way to control the ecological problems in the Three Gorges Reservoir area, the key lies in the selection of suitable tree species. The Zhongshan fir, metasequoia, Salix variegata, mulberry plants of the four strong adaptability as the research object, through the simulation of Three Gorges Reservoir Stress Characteristics Experimental Study of four kinds of plant resistance to water flooding, "morphological drought and flooding drought stress, physiological and biochemical reactions and their correlation, and comprehensive comparison of four kinds of plant water stress resistant ability, provides certain theory on the basis of the Three Gorges Reservoir area for the phytoremediation of tree species selection and planting altitude range. After the field survey found that Nakayama Sugi is to repair the excellent candidate species of vegetation in Three Gorges Reservoir area, reservoir to adapt to the complex environment in the sea 168-175 meters out of riparian zone to survive, in-depth discussion on "flooding drought" alternating stress adaptability, with high scientific and practical value. This paper is divided into two stages of stress test of waterlogging and drought resistance of four species of "flooding", "drought" and "flooding drought" stress. The first stage of flooding test set flooded group and control group. After 40 days of flooding in winter dormancy after treatment, four plants had different morphology: to adapt to the change of air film Nakayama Sugi and Metasequoia leaf surface; adventitious root Nakayama Sugikim; Zhongshan fir, metasequoia, Salix variegata leaf Quanyan group the specific leaf weight were lower than the control group; these changes facilitate gas exchange, enhance plant tolerance to waterlogging stress. After flooding stress of four kinds of plant photosynthetic pigments have different adaptive changes. Four plants flooded leaf Green was significantly lower than the control group, indicating chlorophyll synthesis in winter flooding stress affected plant leaves; Zhongshan fir, metasequoia and mulberry flooded group of chlorophyll a/b values were compared with the control group decreased, the chlorophyll a/b value decreased to maintain a relatively normal plant photosynthetic efficiency. The whole group of four plants. Malondialdehyde (MDA) content were increased compared to the control group, while the root activity decreased, indicating that four kinds of plants in the winter dormant period of flooding stress was subject to a certain degree of injury; flooded group of four kinds of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activity were significantly higher than the control group, the inhibition rate of MDA accumulation in vivo, belongs to a positive response in plants in response to waterlogging stress, to maintain a certain degree of the physiology of plants in the water flooded after the stress of normal students The behavior of four species of submergence group. Proline, soluble sugar, soluble protein content increased compared to the control group, help plants to maintain high water absorption and water retention in water stress, nitrogen metabolism of plants to maintain normal; but the whole group flooded variegata soluble sugar content was lower than the control group, the content of soluble protein in the fully flooded group than in the control group the specific reasons of mulberry, need further study. The second stage of drought stress test is divided into full control group (CC group), early late normal processing drought treatment (group CD) and early late flooding drought treatment (group FD). To the winter dormancy stage of waterlogging stress four planting plant growth is completely restored for 20 days of drought treatment in July 5, 2016. Of the four plants after drought stress, chlorophyll content and root activity of CD group was significantly lower than that of CC group, CD group C four plants Two aldehyde content were higher than CC group, indicating four kinds of plants under drought stress on photosynthetic pigment degradation or synthesis process is blocked, the root activity under stress, cell membrane damage caused by MDA content increased. The four group CD plant chlorophyll a/b values were lower than CC group, that can adjust the chlorophyll a/b to maintain a relatively normal photosynthetic efficiency of plants under drought stress. Four species of CD group activity of antioxidant enzymes and contents of osmotic adjustment substances were higher than CC group, shows four kinds of plants can activity and osmotic adjustment substances to adapt to drought stress by regulating antioxidant enzymes. Four kinds of plant physiological and biochemical response to positive in response to drought stress, with drought tolerance of four species of FD group. The content of chlorophyll, chlorophyll a/b values were decreased compared with CC group, the largest decline in four species of Metasequoia; FD group and CC group compared to MDA Have increased significantly, and root activity were significantly decreased in FD group; antioxidant enzyme activity and osmotic adjustment substances were higher than CC group; these changes show that the four kinds of plants can photosynthetic pigment by adjusting the light body, the activity of antioxidant enzymes and contents of osmotic adjustment substances to water flooding - dry alternating stress, but has the ability to adapt the difference, may be their special physiological and biochemical mechanism. After water flooding caused by drought stress, "Zhongshan fir in MDA and SOD, POD showed significant positive correlation with proline; Zhongshan fir mainly rely on these three substances to inhibit the accumulation of MDA. MDA and CAT APX in Metasequoia, showed a significant positive correlation, and MDA a significant negative correlation with root activity, indicating the Metasequoia mainly depends on CAT, APX activity increased to inhibit the accumulation of MDA, increase the MDA content of Metasequoia will affect root vigor. Variegata MDA content and CAT, APX, soluble sugar was A significant positive correlation, indicating variegata mainly depends on CAT, APX, soluble sugar to inhibit the increase of MDA; while MDA showed a significant negative correlation with the activity of root, increase the content of MDA Qiu Hua Liu that influenced mulberry root activity. MDA content and SOD, soluble protein showed a significant positive correlation, indicating mulberry plants mainly rely on SOD and soluble protein to inhibit MDA accumulation rate. Using the method of membership function analysis of two stage. The results showed that four species of submergence tolerance ability as follows: Salix variegata Zhongshan fir Metasequoia mulberry; four plant drought tolerance ability is as follows: four Nakayama Sugiaka Liu mulberry Metasequoia; plants "flooding drought" alternating stress Qiu Hualiu is as follows: the Zhongshan fir mulberry metasequoia. Four species of plants in the Three Gorges reservoir ecological restoration is an excellent alternative species by morphology, antioxidant system, osmotic regulation system to adapt to the Three Gorges The stress of winter waterlogging and summer flooding in the reservoir area is of high ecological value and economic value.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q945.78

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