| 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 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...
|
PDF Full Text Request