Study On Ecological Anatomy Of Different Spring Wheat Varieties

Spring Wheat is a kind of annual plants of Triticum aestivum L. of Gramineae which has a widespread distribution and is also main food crop in northwest and northern China. This Paper is with the different habitats (dry land and water land), take for the stem and leaf of different types (Xi han No.1 and Long chun No.1) spring wheat as the research material, and use optics microscope to observe and research the structure of stem and leaf. 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. Ascertaining by measuring cuticle cell of the leaf, cuticle and collenchyma's thickness;The type and the size of epidermis cell, epidermis hair, stomata apparatus and inside leaf tissue and so on. Comparing all the indexes, several major conclusions can be drawn as follows:1. Each part of plant is mutual co-ordination to accomplish certain physiology function. Research has shown that spring wheat in different habitats (dry land and water land) has changed that the leaf became to suit the ecology environment. Some changes can occur on the growth course of dry land, the change of leaf is the dearest, and the major show is fighting drought nature changes of the physiology characteristics; the thickness of the leaf which grows on dry land 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 cuticle is flourished, moisture content losing is reduced and strong lights'shining is reflected. The mechanical tissue is flourished, and it can reduce injury when leaf wilt, and preventing the lights 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 stem. The density of stem epidermis lenticels which lives on dry land is 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 spring wheat which lived on dry land is thicker, and it can increase the stem protective laver of the outside. Spring wheat which lived on dry land 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 stem and leaf's dissected form, it is shown that spring wheat has two different types; dry wheat and water wheat. From the form dissected of leaf we can know and, the thickness of leaf in palisade tissue, the types of vascular bundle, the flourishing level of mechanical tissue, the form of epidermis cell, the types of pattern of anticline walls of epidermal cells and neighboring cells, the size of stoma, the density of up and down epidermis, they are all different each other. Moreover, the two kinds stems of spring wheat. 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 reflects the affinity relation between them, namely the same clan but different species.4. By researching the fighting a drought nature of the two types spring wheat. It is shown that Xi Han No.1 is the better type than Long Chun No.1 chiefly showing: the blades of Xi Han No.1 is bigger that the average thickness of Long Chun No.1, the number of layers is more, the density of blades is bigger, the level of mechanical tissue is flourishing, the stoma ware is small, the collenchyma is flourishing. And the stem epidermis cell of Xi Han No.1 is thicker than Long Chun No.1, the density of lentice is big, the cortex is thick, the pith is big, this index was showed that Xi Han No.1 was drought more than Long Chun No.1. Contrast on the change of dissected form of Xi Han No.1 and Long Chun No.1 form water land to dry land . It was showed that Xi Han No.1 can suit the changes of ecological environment better from the moist environment to the drought environment, the physiology form structure of Xi Han No.1 is better than Long Chun No.1 to drought-resistant nature, and it is show that Xi Han No.1 is better than Long Chun No.1 in drought-resistant nature farther more.