枫香属植物对不同程度干旱胁迫的响应毕业论文.doc

硕士学位论文枫香属植物对不同程度干旱胁迫的响应Plants of the genus (liquidambar.) with different degree of drought stress responseTCLC: Secrecy: UDC : No. : Plants of the genus (liquidambar.) with different degree of drought stress responseA Thesis Submitted toYunnan Agricultural UniversityIn Special Fulfillment of the Requirement for the Master Degree of Environmental ScienceCandidate: Zhang Ling Supervisor: Prof. Duan Hongping and Chen YitaiKey Laboratory of Plant Pathology of Yunnan ProvinceYunnan Agricultural UniversityKunming, 650201, CHINAMay 2013 枫香属植物对不同程度干旱胁迫的响应目录摘 要1ABSTRACT31文献综述61.1枫香属植物的研究概况61.1.1枫香属植物的分类、分布、用途及生物学特性61.1.2 枫香属植物的国内外研究进展71.2林木生长和水分状况的关系91.2.1水分与植物生长的关系91.2.2水分亏缺对植物叶绿素荧光参数的影响101.2.3 水分亏缺对植物抗氧化酶活性的影响111.2.4水分亏缺对植物养分吸收的影响121.2.5 水分亏缺对植物渗透调节作用的影响131.3研究目的与意义132 材料与方法162.1技术路线162.2研究方法172.2.1供试材料172.2.2试验设计172.3 研究内容与指标测定方法172.3.1 植株生长指标的测定172.3.2植株生理生理生化指标的测定182.3.2.1 植株SPAD值与叶绿素荧光参数的测定182.3.2.2 植株部分抗氧化酶活性的测定192.3.2.3 植株养分含量的测定192.3.2.4 植株渗透调节物质含量的测定191)有机渗透调节物质含量的测定192)无机渗透调节物质含量的测定193) 水分指标的测定202.3.2.5 质膜相对透性的测定202.3.2.6 根系活力测定202.4 数据处理与综合评价方法213结果与分析213.1干旱胁迫对3种枫香植株生长的影响213.1.1 干旱胁迫对幼苗成活率的影响213.1.2干旱胁迫对3种枫香幼苗株高生长的影响223.1.3 干旱胁迫对枫香幼苗生物量的影响243.2干旱胁迫对3种枫香叶片生理生化指标的影响253.2.1干旱胁迫对枫香幼苗叶绿素荧光参数的影响253.2.1.1 干旱胁迫对3种枫香叶片Fv/F0值的影响253.2.1.2 干旱胁迫对3种枫香叶片Fv/Fm值的影响273.2.1.3干旱胁迫对3种枫香叶片PS的影响283.2.1.4 干旱胁迫对3种枫香叶片qP的影响293.2.1.5 干旱胁迫对3种枫香叶片NPQ的影响313.2.1.6干旱胁迫对3种枫香叶片ETR的影响323.2.1.7 不同程度干旱胁迫对枫香叶片荧光参数的影响333.2.2水分亏缺对枫香幼苗叶片部分抗氧化酶活性的影响343.2.3干旱胁迫对枫香幼苗叶片养分含量的影响353.2.4干旱胁迫对枫香幼苗叶片渗透调节作用的影响363.2.4.1干旱胁迫对枫香幼苗叶片有机渗透调节物质含量的影响363.2.4.2 干旱胁迫对枫香幼苗叶片无机渗透调节物质含量的影响373.2.4.3 干旱胁迫对枫香幼苗叶片水分含量的影响383.2.4.4 干旱胁迫对枫香幼苗叶片水势与土壤含水量之间的变化关系403.3 干旱胁迫对3种枫香幼苗根系形态及生理功能的影响423.3.1 干旱胁迫对3种枫香根系构型的影响433.3.2干旱胁迫对枫香根系养分含量的影响443.3.3干旱胁迫对枫香根系保护酶活性的影响453.3.4干旱胁迫对枫香根系膜脂过氧化作用的影响463.3.5 干旱胁迫对3种枫香根系渗透调节物质含量的影响463.3.5.1干旱胁迫对3种枫香根系有机渗透调节物质含量的影响463.3.5.2 干旱胁迫对3种枫香根系无机渗透调节物质含量的影响483.3.6 干旱胁迫对3种枫香根系活力及生物量分配的影响483.4 3种枫香叶片与根系指标的抗旱性综合评价503.4.1 3种枫香叶片抗旱性指标筛选与评价503.4.2 3种枫香根系抗旱性指标的筛选与评价513.4.3 3种枫香幼苗的耐旱性综合评价524讨论544.1水分亏缺与枫香属植物生长的关系554.2水分亏缺与枫香叶绿素荧光参数的关系564.3水分亏缺对枫香养分吸收的影响574.4 水分亏缺对枫香保护酶活性的影响584.5 水分亏缺与枫香渗透调节作用的关系594.6 水分亏缺对枫香根系构型及生理功能的影响605结论615.1枫香幼苗生长及表型变化对干旱胁迫的响应615.2 枫香叶片生理生化反应对干旱胁迫的响应625.3 枫香根系形态及生理对干旱胁迫的响应635.4 3种枫香幼苗的耐旱性综合评价63参考文献64致 谢70枫香属植物对不同程度干旱胁迫的响应摘 要枫香属（Liquidambar.）植物为金缕梅科落叶乔木，作为我国南方林区主要造林树种，适应性、萌芽力强，天然更新容易，生长迅速，抗污能力强，耐干旱瘠薄，生长适应性广，不仅具有重要的生态学意义，还具有广泛的生产应用价值。本研究采用随机区组试验设计，自然干旱法，以正常浇水为对照，依据干旱时间设置处理水平，对3种枫香两年生实生苗进行干旱胁迫试验，每隔4-6d开始测定各项动态指标，一个月后复水观察统计死亡率，测定部分生理生化指标，保留一半，继续干旱处理另一半，干旱至60d时复水一周，统计死亡率，测定部分生理生化指标，通过反复干旱试验，以探讨3种枫香苗的耐旱性强弱，结果如下：（1）干旱30天复水后，缺萼枫香无死苗现象，中国枫香死亡率为0.85%，北美枫香死亡率为5.12%；干旱60d后复水一周发现，3种枫香都出现了一定程度的死苗现象，缺萼枫香死亡率约为18%，中国枫香与北美枫香死亡率分别为19.66%、6.84%。株高净生长量随干旱胁迫时间的延长一直处于降低的趋势，总体生长幅度低于对照组。3种枫香幼苗生物量随干旱胁迫时间的延长，根、茎、叶、总生物量均降低，叶重比随干旱胁迫时间的延长处于降低趋势，茎重比升高，根重比先降低后又升高。表明干旱胁迫会改变枫香株高生长、生物量在各器官间的分配比例以及幼苗存活率，其中根、茎比例增加和叶重比减少会有利于其在干旱条件下吸收水分和维持水分平衡。（2）短期（30d）干旱胁迫条件下，3种枫香Yield、qP、ETR在干旱12d左右均出现不同程度地降低，NPQ则出现缓慢上升的趋势。Fv/F0、Fv/Fm在干旱24d左右开始降低。缺萼枫香与中国枫香在短期干旱（30d）与长期干旱（60d）胁迫下，其Yield、Fv/F0、Fv/Fm、qP、ETR降低，NPQ升高，而北美枫香各参数在短期干旱（30d）时与对照相比均无明显差异,处理60d后与对照组相比，其Yield、qP、Fv/F0、qN、ETR降低，Fv/Fm不变。说明枫香苗叶片色素吸收的光能出现不正常的散失，导致暗适应条件下的初始荧光值增大，即荧光发射散失的能量比例增大。（3）缺萼枫香在短期（30d）干旱条件下，叶片SOD活性上升、SOD/CAT值降低、MDA含量降低，长期干旱（60d）则导致SOD活性降低、POD活性升高、SOD/POD、SOD/CAT值与对照组相比均有所降低；中国枫香在短期干旱（30d），叶片SOD活性降低，POD活性升高，SOD/POD、SOD/CAT值降低，MDA含量升高，CAT活性无明显变化，长期干旱（60d），SOD活性升高，SOD/POD值升高,SOD/CAT值降低,MDA 含量降低。北美枫香在短期干旱（30d），叶片SOD/POD值上升，MDA含量升高,长期干旱（60d），SOD与POD活性均出现不同幅度地降低，SOD/POD值升高。中国枫香根系SOD活性、CAT活性均表现出先升高后降低的趋势，POD活性先降后升，SOD/POD值降低，SOD/CAT值先升高后降低；缺萼枫香根系SOD活性、CAT活性先降低后升高，SOD/POD值、SOD/CAT值先升高后降低，POD值升高；北美枫香的SOD活性、CAT活性、SOD/POD值先升高后又降低，POD活性、SOD/CAT值降低，MDA含量均处于上升趋势。说明在一定的胁迫程度和时间内，枫香能够激活 SOD、POD 、CAT等酶活性来调节胁迫对其造成的伤害。（4）随干旱胁迫时间的延长，枫香叶片有机碳含量无显著变化，缺萼枫香叶片N含量有所上升,中国枫香无一致变化，北美枫香在干旱60d以后叶氮量降低。缺萼枫香叶片C/N表现出一定程度的下降趋势，中国枫香与北美枫香则表现出一定的上升趋势，根系有机C、全N、C/N比均随干旱胁迫程度的变化，表现出明显的种间差异。（5）3种枫香叶片可溶性糖、可溶性蛋白、脯氨酸等有机渗透物质含量都有不同程度的上升趋势，根系有机渗透调节物质可溶性蛋白、脯氨酸含量均有上升的趋势，可溶性糖含量无一致变化，叶片Ca2+、Mg2+含量稍有降低的趋势，K+含量有上升的趋势，根系无机渗透离子（Ca2+、K+、Mg2+）含量均稍有上升的趋势。在短期内，随干旱时间的延长，3种枫香叶片相对含水量（RWC）逐渐降低，水分饱和亏缺(WSD)逐渐升高，组织密度(TD)在干旱的前12d有所降低，在干旱的后期有逐渐升高的趋势，3种枫香叶水势随土壤含水量的降低逐渐升高。（6）3种枫香根系比根长(SRL)、比表面积(SRA)、相对表面积(RSA)均表现出先升高后降低的趋势，平均直径(ARD)表现出先降低后升高的趋势，随干旱胁迫时间的延长，3种枫香根系活力表现出明显的种间差异，其中中国枫香随干旱时间延长根系活力上升，缺萼枫香有升有降，北美枫香则随干旱胁迫时间的延长根系活力一直处于下降的趋势，根系相对电导率及根冠比升高。表明短期干旱促进了枫香苗根系的生长，长期干旱抑制了根系生长。（7）通过主成分分析对3种枫香叶片与根系的性状指标进行筛选，优选出最具代表性的21项指标对3种枫香实生苗的抗旱性进行评价，结果表明3种枫香的耐旱性强弱顺序依次为缺萼枫香>北美枫香>中国枫香。关键词：干旱胁迫；枫香；死亡率；荧光参数；抗氧化酶活性；根系形态；渗透调节Response of plants of the genus (Liquidambar.) to different degree of drought stress Zhang Ling (Environment Science)Directed by professor Duan Hongping and Chen YitaiABSTRACT (Liquidambar.) plants is the deciduous arbor, which belongs to hamamelidaceae , (Liquidambar .) as one of the main forest tree species in south China, has characteristics of powerful adaptability, powerful budding force, natural regeneration, rapid growth and resistant to contamination; It can survive in the dry barren mountains, hillsides, cliffs and stones and grow well in red soil. Growth and adaption widely, Not only it has important ecological significance, but also has extensive application value in production. This research adopts randomized block experiment design, with normal irrigation as contrast, on the basis of drought time setting treatment, the three kinds of sweet gum was born two years the west to drought stress test, natural dry method is used, every 4 to 6 d to determine the dynamic indexes, a month later after water watch mortality statistics, determination of some physiological and biochemical indicators, keep half, continue to drought do the other half, when drought and 60 d after water week, mortality statistics, determination of some physiological and biochemical indicators, through repeated drought experiment, to research the drought resistance strength of three kinds of maple seedlings, the results are as follows:(1)After 30 days water deficit and recover, L.acalycina no deadth phenomenon, L.formosana and L.styraciflua are appear different degrees of death phenomenon, L.formosana mortality was 0.85%, and L.styraciflua mortality was 5.12%; after drought 60 d found that three maple seedlings are different degrees of death phenomenon, L.acalycina mortality was about 18%, China of north American maple with liquidambar L.formosana and L.styraciflua mortality were 19.66%, 6.84% respectively.Plant height net growth along decreased with the elongation of drought stress time. with the prolonged drought stress has been on the decrease tendency, in the arid first 18 d reduce tendency obvious, leveling off after 18 d, the overall growth rate is lower than the control group.Three kinds of sweet gum seedling biomass with the elongation of drought stress time, the root, stem and leaf, total biomass were under lower trend, leaf weight ratio with trend of reduce in the extension of drought stress time, stem weight than up, the root weight ratio first decreases and then increases. It will facilitate the absorption of moisture indry conditions and maintenance of water balance.(2)Short-term (30 d) drought stress conditions, the actual photosynthetic efficiency of three kinds of sweet gum (Yield), coefficient of photochemical quenching (qP), non cyclic electron transport rate (ETR) in drought around 12 d are reduced in different degrees, NPQ was a slow upward trend. PS potential activity (Fv/F0), maximum quantum yield of photochemical reaction (Fv/Fm) in drought around 24 d began to decrease. L.acalycina and L.formosana in the short term drought (30 d) and long-term (60 d) drought stress, the Yield, Fv/F0, Fv/Fm, qP, ETR is reduced, NPQ increased, while the L.styraciflua each parameter in the short-term drought (30 d) there were no obvious difference compared with controls, processing after 60 d compared with the control group, the actual photochemical efficiency coefficient (Yield) and photochemical quenching (qP), PS potential activity (Fv/F0) and photochemical quenching coefficient (qN), non cyclic electron transport rate (ETR) is reduced, the PS maximum photochemical efficiency (Fv/Fm) remains the same.Illustrate maple seedlings leaf pigments absorb light energy dissipating appear abnormal, leading to the condition of dark adaptation the initial fluorescence value increased, the fluorescence emission dissipating energy ratio increased.(3)L.acalycina in short term (30d) under drought condition, leaf SOD activity increased, SOD/CAT value decreased, MDA content decreased, the long drought (60 d) results in the decrease of SOD activity, POD activity increased, SOD/POD, SOD/CAT were decreased compared with control subjects; L.formosana in the short-term drought (30 d), the leaf SOD activity decreased and POD activity increased, SOD, POD, SOD/CAT value decreased, MDA content increased, the CAT has no obvious change, and prolonged drought (60 d), the SOD activity increased, SOD/POD increased value, SOD/CAT value decreased, MDA content decreased. L.styraciflua in the short-term drought (30 d), leaf SOD/POD value rise, MDA content increased, the long drought (60 d), SOD and POD activity showed different amplitude reduced, SOD/POD value increased. L.formosana root SOD activity, CAT activity showed a trend of reduce the rise, fall after rise first POD activity, SOD/POD value is reduced, SOD/CAT value increases after the first reduce; L.acalycina root SOD activity, CAT activity increased after lower first, SOD/POD, SOD, CAT values decrease after rising first, POD value increased; L.styraciflua SOD activity, CAT activity, SOD/POD value first increased and then decreased, POD activity, SOD/CAT value decreased, MDA content are rising. Indicated a certain stress level and time, Liquidambar.able to activate SOD, POD,CAT activity to regulate the stress of their damage.(4)Maple leaf organic carbon content has a slow upward trend with the elongation ofdroughtstress time., but the upward trend is not obvious, L.acalycina leaf N content is increased, there is no consistent change in L.formosana, L.styraciflua leaf nitrogen content decrease after drought 60 d. L.acalycina leaf C/N showed a certain degree of decline, L.formosana and L.styraciflua was showed a rising trend. the root system of organic C, total N and C/N ratio changes with the degree of drought stress, showing obvious differences between the species.(5)Three kinds of sweet gum leaf soluble sugar content, soluble protein content, proline content has the varying degree rise, the root system of organic osmoregulation substances soluble protein and proline content were rising trend, no consistent change in soluble sugar content .Ca2+, Mg2+ content is slightly lower trend, K+ content has a tendency to rise, root penetration of inorganic ion (Ca2+, K+, Mg2+) levels were slightly rising trend. In the short term, with the extension of drought time, three kinds of maple leaf relative water content (RWC) gradually reduced, water saturation deficit (WSD), organization (TD) in dry density before 12 d, has a rising trend in the late dry, three maple bay leaf water potential increased with the decreasing of soil water content.(6)Three kinds of sweet gum specific root length (SRL), specific surface area (SRA), relative surface area (RSA) all showed a trend of reduce the rise, but long-term drought (60 d) causes specific root length (SRL), specific surface area (SRA), relative surface area (RSA) decreases, and the average diameter (ARD) showed lower before rising trend, with the elongation of drought stress time, the three kinds of sweet gum root activity showed obvious interspecific differences, including L.formosana fragrance rising along with the prolonged drought, root activity, L.acalycina and L.styraciflua were the extension of drought stress time, root activity has been in a downward trend, root relative electrical conductivity and root cap ratio increases. It demonstrated that short-term drought promotes liquidambar seedling root growth, long-term droughts inhibit the growth of the root system.(7)Through principal component analysis to three kinds of maple leaf and root traits of index screening, selected the most representative of 21 indicators to evaluate drought resistance of the west between three kinds of sweet gum, the results showed that the drought resistance of the three kinds of sweet gum strength order is L.acalycina > L.styraciflua > L.formosana.Key words: Drought stress, sweet gum, mortality, fluorescence parameters, antioxidant enzyme activity, root morphology, osmotic adjustment1文献综述1.1枫香属植物的研究概况1.1.1枫香属植物的分类、分布、用途及生物学特性枫香树属（Liquidambar）植物为虎耳草目枫香科下的一属，以前也曾被纳入金缕梅科（Hamamelidae），在北半球第三纪到第四纪广泛分布，北美地区第三纪、东亚日本、中国、欧洲的第三纪可以见到枫香类植物保存的叶片，木材，聚合果化石，属第三纪孑遗植物。在我国枫香属植物分布时间范围很广、著名山旺中新世、浙江临海下南山中新世、南宁凤岭均发现过叶片化石，至今保留下来的枫香属植物约有5个对应现代种，同样在西亚、东亚到北美仍旧有分布、但是分布区仅局限在温暖湿润的亚热带、北热带范围内，是一个典型的亚热带性质的属。枫香属包括中国枫香(L.formosana) 苏合香 (L.orientalis) 缺萼枫香(L.acalycina) 美国枫香 (L.styraciflua) 4 个种和枫香的一个变种山枫香 (L.formosana var.monticola) 其中中国枫香、缺萼枫香、山枫香分布于我国华北以南、台湾、老挝、越南北部地区，为东亚种，苏合香为西亚种，主要分布在土耳其西南部和希腊的罗得岛地区，美国枫香为北美种分布于北美洲东部，从纽约州到墨西哥东部以及危地马拉。枫香属的同工酶1和分子系统发育2的研究表明，苏合枫香与北美枫香具有更近的亲缘关系比起其他现存的种，因为他们生活在相同的气候条件下，尽管地理位置不同（shi. etal）3支持北美枫香与苏合枫香是复系（并系）种，以及morris等4评估了这两个种具有相同的分支时间，根据分析的五个非编码序列数据，他们证实了其他研究人员的发现。 枫香属植物在我国主要分布于长江流域及其以南地区，西至四川、贵州、云南，南至广东，东至台湾，垂直分布于海拔在1000-1500m的南方丘陵及平原地区。枫香属植物是我国亚热带地区优良速生落叶阔叶树种，在鄂东南低丘马尾松林中是重要的伴生树种，其在天然和人工林的更新中具有重要的意义5，也是改良土壤、美化环境、保持水土的首选树种，其性耐火烧,耐干旱瘠薄，素有“荒山先锋”之称,也是香茹、木耳栽培段木的重要来源。其材质均匀，纹理美观,是胶合板和造纸的良好用材树种,具有广泛的利用价值6。此外，枫香树冠广裘，气势雄伟；十月上旬秋叶色泽始红，渐五彩斑斓、靓艳醉人，为欧美著名园景树种、行道树，被广泛种植在小区庭园、公园绿地和风景区等场所：孤植、丛植、群植均相宜，纯林者，霜侵红叶、层林尽染，更为壮观。更因生长快、生物量大、萌发力强、根深抗风，很强的土壤适应性,水域边林地、干燥沙地都能生长，同样适合做用材林、防护林和湿地生态林。因其对SO2、Cl2有较强的抗性，适合在污染较重的工厂、城区栽植绿化，其树脂有香气，可用来调配香料，其树皮、叶片、果实含有丰富的萜类、黄酮类、酚酸类、苯丙素类、挥发油类化合物，可作为治疗湿热肿毒等症状的中药材。总之，枫香树属植物所含化合物类型丰富，药理作用多样且显著，具有很高的药用价值。枫香为高大落叶乔木，幼树树皮灰褐色，平滑，老树树皮暗褐色，有粗糙的纵裂痕，单叶互生 3-5 裂(偶而可见 1-2 裂) 多为草质或革质,边缘有细锯齿,冬季变黄或变红,春季新叶与花约同时绽开，花单性，雌雄同株，雄花为密集的圆锥花序，有许多黑色的小鳞片混生，雌花头状花序，花柱2枚，紫红色，也有少许的鳞片混生，枫香系风媒授粉的异系交配体系，3- 4月开花，10月下旬果实成熟，枫香果穗球形，果径 2.5-3.5cm，由多数蒴果组成。蒴果2裂，具宿存的花柱及刺状萼片，种子黑褐色，长椭圆形，微扁，长6-7mm，宽2mm，顶端及两侧有翅，连翅长8-10mm,每一蒴果内仅1-2枚可孕性种子，其余多数为不孕性种子，且细小，多角形，黄白色，无翅，枫香结实大小年现象明显。1.1.2 枫香属植物的国内外研究进展早在20 世纪 60 年代，国外对枫香属植物进行了广泛的研究，主要对美国枫香、苏合枫香进行了比较全面的研究，包括栽培、育种等方面。Wells7等人对美国枫香的地理变异研究开展得较早，Honey1对采用同工酶分析的方法来研究美国枫香，苏合香，缺萼枫香的种间分化关系。分析了 22 个同工酶位点，统计分析出种间的聂氏遗传距离和遗传相似系数 ，Hoey等8还研究了美国枫香、枫香、缺萼枫香群体内和群体间的遗传变异，发现在美国枫香的两个起源地美国东部和墨西哥的群体内的分化较小,且群体间的遗传相似系数很高,说明两地的亲缘关系较近枫香和缺萼枫香群体内的分化也较小,群体间相似系数很高,枫香与缺萼枫香之间也有较高的遗传相似系数 0.82 说明枫香与缺萼枫香之间是亲缘关系较近的种（Li etal）9 用 matK 基因的序列研究枫香属种间的遗传分化根据其基因差异得出了枫香、美国枫香、苏合香之间的