【作者】 王金照；

【导师】 张文辉； 张景群；

【作者基本信息】 西北农林科技大学 ， 植物学， 2004， 硕士

【摘要】 栓皮栎（Quercus variabilis BI.）为壳斗科（Fagaceae）栎属（Quercus Linn.）分布极为广泛的乔木树种，也是我国暖温带海拔1 600m以下地区重地带性植被的主要组成树种。论文以不同生境（阳坡、阴坡）、不同类型（厚皮、薄皮）栓皮栎的叶片和一年生茎为研究材料，利用光学显微镜和电子扫描镜对栓皮栎叶片和茎的微特征结构进行观察研究。测定出叶片表皮细胞、角质层和厚角组织厚度，表皮毛、气孔器和叶内组织的类型、大小等；测定出茎的表皮细胞厚度，表皮毛的类型和密度，皮孔密度，皮层、栓皮层、维管组织和髓的厚度，计算皮层与半径之比，维管组织与半径之比，髓与半径之比等。对所有指标进行比较研究，获得了如下主要结论：1．植物体的每一部分都是相互协调的共同完成某一生理功能。研究表明不同生境（阳坡，阴坡）栓皮栎叶的解剖形态发生了适应生态环境的变化，在阳坡栓皮栎在其生长过程中就会发生一些形态结构上的变化，叶片的变化最为快速明显，表现为抗旱性的生理变化特征。主要表现为阳坡栓皮栎的叶片厚度增厚，增加植物的保水能力；表皮毛密度增加，阻碍强光辐射，减少水分份的蒸发；栅海比增高，角质层发达，减少水分丧失，反射强光的照射；机械组织发达，减低叶萎蔫时的损伤，同时阻挡光线直接辐射，而达到降低蒸腾的作用。因而，植物在干旱条件下，向着抗旱性方面发展的适应性变化趋势，一方面是减少水分份的丧失控制蒸腾；另一方面是提高本身的光合效能。2．随着环境的不同，生态因子的变化，不仅植物的叶片会发生生理结构上的变化。在阳坡栓皮栎茎表皮皮孔密度大，有利于植物的蒸腾和气体交换，保持植物体内水分份含量；茎表皮毛密度大，阻碍水分份在干条件下丧失过快，遮挡强光辐射；阳生栓皮栎皮层较厚，增加茎外侧的保护层；阳生栓皮栎具有较大的髓部，这种大型的贮水薄壁组织，是植物抗旱性植物茎肉质发育进行的另一条途径。3．形态解剖学早已运用到植物的系统分类之中，通过对栓皮栎叶、茎的形态解剖研究，发现栓皮栎中存在两个完全不同的类型：厚皮栓皮栎和薄皮栓皮栎。从叶的形态解剖可知薄皮栓皮栎与厚皮栓皮栎，叶在在栅栏组织海绵组织的厚度，栅海比；维管束类型，机械组织发达程度；上下表皮细胞形态，垂周壁类型；气孔大小，上下表皮分布密度等方面均有明显差异。另外，两种类型栓皮栎茎，在表皮细胞厚度；表皮毛密度；皮层厚度；栓皮层厚度及髓的大小等方面都具有一定的形态结构差异，表明栓皮栎确有两个不同的种类。而这种之中且存在的微特征结构的相似性，又反映出他们之间的亲缘关系。 <WP=6>4．通过对两种类型（厚皮、薄皮）栓皮栎抗旱性研究发现，薄皮栓皮栎是比厚皮栓皮栎更具抗旱性的优良类型。主要表现为：薄皮栓皮栎叶片比厚皮栓皮栎叶片平均厚度大；栅栏组织层数多，栅海比高；叶表皮毛密度大；机械组织发达；气孔器小；厚角组织发达等。同时薄皮栓皮栎茎比厚皮青冈茎表皮细胞厚；皮孔密度大；皮层厚；髓大等，这些指标均表明薄皮栓皮栎比厚皮栓皮栎更具抗旱性。另外通过对照薄皮栓皮栎与厚皮栓皮栎从阴坡到阳坡的解剖形态变化,可以得知：薄皮栓皮栎更能适于环境生态因子的变化，从湿润环境到干旱环境，薄皮栓皮栎的生理形态结构向抗旱性变化强于厚皮栓皮栎，进一步说明薄皮青冈栓皮是比厚皮栓皮栎更具抗旱性的优良品种。更多还原

【Abstract】 Q. variabilis is a kind of Fagaceae Quercus which has a widespread distribution area and is also the major regional tree of the warm temperate zone below altitude 1 600 meter in China. This essay is with the different habitats (Sun slope and cloudy slope), take for the blued and annual stem of different types(thick bark and thin bark) Q. variabilis as the research material, and use optics microscope and electronic scanning lens to observe and research the structure of blade and stem. Ascertaining by measuring the blade, cuticle cell, cuticle and collenchyma’s thickness. The type and the size of epidermis cell, epidermis hair, stomata apparatus and inside blade tissue；Ascertaining by measuring the epidermis cell thickness of the stem, the type and density of the epidermis hair，the density of lenticel; the thickness of cortex, phellogen, vascular tissue and pith；And calculate the ratio of cortex and radius, the ratio of vascular tissue and radius, the ratio of pith and radius……. Comparing all the quotas, several major conclusions can be drawn as follows:1.Each part of plant is mutual co-ordination to accomplish certain physiology function. Research has showed that. Q. variabilis in different habitats (sunny slope and cloudy slope )has changed that the blade became to suit the ecology environment. Some changes can occur on the growth course of sun slope, the change of blade is the dearest, and the major show is fighting a drought nature changes of the physiology characteristics; the thickness of the blade which grows on sun slope is increasing; the ability of keeping water is increasing; the density of epidermis hair is increasing too. It is also preventing the strong light’s radiation, reducing evaporation; The ratio of palisade tissue and spongy tissue is getting higher. The cuticle is flourished, moisture content losing is reduced and strong lights shining is reflected. The mechanical tissue is flourished, and it can reducing injury when blades wilt, and preventing the light’s directed radiation and reduce evaporation. So plants which live under the drought conditions become turning towards the adaptability of fighting a drought nature. For one thing is to control the evaporation to reduce moisture content losing, for another thing is to increase its ability of photosynthesis.2.As the changes of environment, the changes on the physiology structure can occur on different blades .The density of stem epidermis lenticel which lives on sunny slope in increasing, it is good for evaporating and exchanging gas. Is also keeps the content of moisture contents; the density of stem epidermis hair is increasing. It can prevent moisture forfeiting fast under the drought condition, it also can prevent strong light radiation, the cortex of Q. variabilis which lived on sun slope is thicker, it can increase the stem protective laver of <WP=8>the outside. Q. variabilis which lived on sun slope has the bigger pith, this kind of store water parenchyma is another way that plant can fighting a drought nature.3. Form anatomy is used among the system classification of plant long ago, by researching the blade and stem’s dissected form, ist is show that Q. variabilis has two different types; thick bark Q. variabilis, and thin bark Q. variabilis. From the form dissected of blade we can know the thick bark Q. variabilis, and thin bark Q. variabilis, the thickness of blades in palisade tissue and spongy tissue, the ratio of palisade tissue and spongy tissue, the types of vascular bundle, the flourishing level of mechanical tissue, the form of epidermis cell, the types of pattern of anticlinal walls of epidermal cells and neighbouring cells, the size of stoma, the density of up and down epidermis, they are all different each other. Moreover, the two kinds stems of Q. variabilis. Their thickness of epidermis cell and cortex，density of epidermis hair, thickness of phellogen and the size of pith all has certain difference in form and structure. And the similarity of minute characteristic structure that just exists among this kind更多还原