| On the basis of previous studies, the content changes of nutrient and related enzyme activity seed germination, the relationship between clonal architecture, cloning component and the environment, and anatomy of cutting reproduction were studied by wild investigation and room experiment method in the Tetraena mongolica Maxim.. The study is to explore the reproduction countermeasures and update strategy of populations in the arid environments. The results have an important practical significance to protect desert vegetation and eco-system.In this paper, the mainly results were as follows:1. Seed of T. mongolica Maxim with smaller, nutrients mainly store in the cotyledons, proteins and sugar. T. mongolica Maxim. seed stored more high-energy matter are conducive to survive in the arid environment.2. Seed coat of T. mongolica Maxim. not inhibited to absorb water of seed, but seed germination was not inhibited. Toughness of seed coat was larger. There were significant differences thickness of seed coat of different parts and different seeds. The seed germinated firstly with thin of seed coat, small toughness and high vigor. The seed coat inhibited germination was to old seed, vigor declined, the contradictions were increasing lead to one of the factors endangered. Tough seed coat made germination continuing under the suitable temperature conditions to reduce individual risk of death and maintain genetic diversity and improve adaptability in adversity of T. mongolica Maxim.3. In the seed germination of T. mongolica Maxim., the content of soluble protein still decreased, the content of soluble sugar increased firstly and then decreased, SOD decreased, POD increased firstly and then decreased. There were significant correlations among the fresh weight, soluble protein, soluble sugar and the activity of SOD、POD.in the seed germination of T. mongolica Maxim.4. The results of anatomy showed that the need energy of T. mongolica Maxim. seed germination. This is starch grains which from protein transfer in the radicle, hypocotyl and cotyledons. The study reveals nutrients consumed rules of T mongolica Maxim. seed germination which is resistant drought plant and provide physiology material of the xeric plants.5. T. mongolica Maxim. has equilateral leaves, epidermis has thickness of cuticle, the stoma distributed in the upper and lower epidermis. Mesophyll structure was ring-palisade, part of total-palisade. Netted venation, veins bifurcated basally. Principal vein became thin from leaf basal. Stem marrow consisted of large sclerenchyma cells, which has store water function. Primary root as diarch and root has no pith. Parenchyma cells of secondary root has "plasmolysis" phenomenon and contained crystals. Part of root secondary phloem existed cells which is discontinuous with thickening of the cell wall. Some of root formed isolated vascular cylinder. Tube of root and stem ditributed a lots of the large of pore size and the thickness of wood fiber cell wall. Starch grains and proteins were rich in stem parenchyma cells, a small amount in leaves and almost no in root. Therefore, the internal structure of nutrition organs of T. mongolica Maxim. adapted to the ecological environment.6. T. mongolica Maxim.has a typical stem structure of woody plant and sclerenchyma was not found in the stem cortex. Stem parenchyma tissues contained abundant starch grains and proteins. There were no latent root primordia in stem cuttings. Root primordia formed by the dedifferentiation of callus parenchyma cells and then developed into adventitious roots. Callus is a prerequisite to the formation adventitious roots and T. mongolica cutting rooting belongs to callus rooting-type. T. mongolica cutting rooting consisted of three stages, including callus and root primordia induction stage, development stage of root primordia and differentiation and elongation stage of adventitious roots.7. After cutting, starch grains were accumulation in the parenchyma cells between phellogen cambium and vascular cambium of stem. Starch grains to achieve high value reduced gradually with callus development continued in the callus development primary. Proteins reduced between phellogen cambium and vascular cambium in the parenchyma cells of stem. Parenchyma cells contained a little of proteins after callus formed. Starch grains and proteins mainly distributed in vigorous divided cells, organ primodium, and adventitious roots cells and nearby cells. Protein and starch provided material and energy to formation and development of adventitious root of T. mongolica Maxim.8. T. mongolica Maxim. has ability to clustered clonal growth, with double clonal organs including root and branch. Three clone growth architecture of T. mongolica Maxim. are phalanx with short spacer from splitter root and guerrilla with long spacer from rhizomatic plant and branch. The clonal architecture related characteristics were differences in different areas. The average of gray correlation was more than0.6between clonal and soil factors. Soil mineral nutrients, potassium K, pH were the key factors to effect clonal of T. mongolica Maxim. Clonal growth of T. mongolica Maxim. made the population with ability to resistant barren and drought, so it adapt to environment strongly. |
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