The Characteristics Of Physio-Biochemical And Features Of Morphological Structure Of Zizyphus Jujuba Mill. Responsed To Grads Drought Stress

The technologies of Plant microtechnology, Scanning ElectronMicroscope, energy spectrum analysis and location of phytohis-tochemistry were used to research the features of morphologicalstructure of root,stem and leaf in Zizyphus jujuba Mill. whichdistributed in gradient drought environment of nature thatconstitutes from Yantai to Xinjiang; The method of potting watercontrol was used to study the characteristics of physio-biochemicalof Zizyphus jujuba Mill. respond to drought stress, to explore the lawof characteristics of physio-biochemical and features ofmorphological structure of Zizyphus jujuba Mill. responsed to gradsdrought stress,the results showed as fellows:(1).The activity of SOD and POD in protective enzymes system ofZizyphus jujuba Mill. were increased in early and decreased later,and it increased as a whole. The activity of CAT was increased earlyand decreased later with drought stress aggravated,and itdecreased with stress duration.(2).The membrane permeability (conductivity) was increasedgradually,the activity of nitrate reductase was ratcheted up,the content of MDA and superoxide anion radical were increasedcontinuing under grads drought stress.(3). The content of osmoregulation substances, such as solublesugar,PRO, AsA, were raised continuing under grads drought stress,and the contents were maximizing respectively under severe stress;The content of soluble protein upped early and reduced later, andmax under moderate stress condition.(4). The contents of photosynthetic pigment, such as gross ofchlorophyll, chlorophyll-a as well as chlorophyll-b, were decreasedunder grads drought stress, chlorophyll a/b upped early and reducedlater, and rised overall;The content of carotinoid increased withdrought stress aggravated and decreased with stress duration, itrose at first and lowered later.(5).In the primary structure of root of Zizyphus jujuba Mill., theepidermic cells arranged tightly, cortex was comprised of large sizeparenchyma cell,which accounted for a large proportion in primarystructure, vascular cylinder was comprised of cells with one ortwo layer that ring arranged.The thickness and width of epidermiccells were increased gradually, parenchyma cell of cortex's rose atfirst and lowered later, pericycle's increased gradually from Yantaito Xinjiang. The size of parenchyma cell was larger,aggregatethickness of cortex was thicker,the area of vascular cylinder wasbigger and the number of plies of cortex cell was more in primarystructure of Zizyphus jujuba Mill. in Nixia than any others'.(6). In primary structure of root of Zizyphus jujuba Mill., the cell waslong-column-shaped and lignification aggrandized in pericapillarycells; the secondary phloem cells were orderly and closely, cambium was clearly, secondary xylem was well-developed andtaken up2/3proportion in secondary structure, there are many bigand thick vessel, xylem ray emitted lengthways between them. Thequantity of vessel was increased, diameter enlarge and efficiency ofwater delivery improved in secondary xylem from Yantai to Xinjiang.(7). In the primary structure of stem of Zizyphus jujuba Mill., thecuticula and stoma located at epidermic cells that arranged closely;cortex was comprised of large number of parenchyma cells thatwere large size, shapes various, and contained a mass of secretorycavity, secretory cell and crystal; Primary xylem, primary phloemand ambium in vascular cylinder were well developed andmorphology clearly; medullary cavum developed and includes manysecretory cells. The thickness and width of epidermic cells wereincreased gradually, the number of plies and thickness ofparenchyma cell of cortex increased successively, the quantity ofsecretory cells were increased and the diameter of myelocytebecame bigger in stem of Zizyphus jujuba Mill. from YanTai toXinJiang. The thickness and width of epidermic cells,the number ofplies and thickness of parenchyma cell of cortex,the diameter ofvessel and myelocyte were maximum in the primary structure ofstem of Zizyphus jujuba Mill. in Nixia.(8).In the secondary structure of stem of Zizyphus jujuba Mill., theepidermis was ecclasis or remaining partly, the structure ofperiderm intact, the cell had fossilized but permutation tidiness;cortex was composed of collenchyma and parenchyma andcontained vug; secondary xylem was well developed, there wereplenty of vessel and emitted xylem ray between them. (9).The leaf of Zizyphus jujuba Mill. was bifacial leaf, stratumcorneum, waxiness and epidermal hair were distributed onepidermis, Lower epidermis distributed a mass of stoma. Themesophyll was palisade tissue overall, palisade cell was columnarand arranged tightly, the palisade tissue was5-6layer. there hadlarge number of crystals and secretory cell. The morphologicalstructure feature of leaf of Zizyphus jujuba Mill. showed regularchanges, and the leaf had the trend that was evolved from bifacialleaf to isolateral leaf.(10).the study by the method of histochemistry locating showed thatthe alkaloid, lipid, flavonoid, saccharide and protein were locatedspecific site in leaf and stem of Zizyphus jujuba Mill.. the metabolinof secretory cell were mainly included alkaloid, lipid, saccharidesand protein.(11).There were six types of vessels,included pitted vessel, spiralvessel, reticulate vessel, annular vessel, scalariform vessel andxylogen vessel,in the root and stem of Zizyphus jujuba Mill..Thevessel could be divided into three types:no tail type,one tail typeand two tails type according the tail, the variation oftype,proportion,and morphological structure characteristics ofvessel had difference in different regions.(12). The leaf of scanning electron microscope showed that the twosides of leaf had plent of epidermal hairs and stomas thatdistributed by law, and contained a mass of crystal that shapediverse and had two distribution form, single crystal and clusteredcrystal. The law of being changed in stoma and crystal wereobviously in differert regions. (13). The energy spectrum analysis showed that the maincomponent of leaves waxiness in Zizyphus jujuba Mill. were C, O, Cathree elements, which C accounts for62.09%,O19.69%,Ca18.22%.The elements of crystalline were all C, O, Ca in the regions of Yantai,Shijiazhuang and Xinjiang, in addition to C, O, Ca, it also containeda little element of Si in crystal of leaf in Ninxia. the regularitydifference of their contents is the result of long-term adaptation.