The Responses Of Structural Evolvement And Physiological In Glycine Under Salt Stress And Alkali Stress

The paper analyses the results of the experiment of salt stress and alkali stress for wildsoybeans--Huinan (salt sensitive) and Tongyu (salt resistant) and cultivatedsoybeans—Zaofen No.5(salt sensitive) and Jiyu No.59(salt resistant). The test has included acomparison of simultaneous structure and a photosynthetic physiological procedure with themethods of paraffin sections and optical microscopy.The elucidation of anatomical structures:1. The paratracheal parenchyma cells of Huinan became bigger at its root under saltstress and the stem catheter chains moved from tangential to radial direction as bast fibercytoplas cells go to the plasmolysis drastically; the palisade tissue of leaves increased with adense formation. When it comes to alkaline condition, the vascular cylinder of root graduallychanged from tetrarch to triarch,the number of the stem catheters was going up and the pithcells were getting bigger, and catheters among which radial chains prevailed with cell wallthickening.2. Tongyu under salt stress,with the pith cells of root increasing,the stem corticalthickening and the cell wall intensive thickening, made the Casparian strip of the endodermisclearer and the number of the vascular cylinder decreased, and then bast fiber lignificationdegree was going to be weak, the vascular cylinder of leaves disappeared, the palisade tissueand spongy parenchyma cells were closely arranged with narrow intercellular spaces, whileunder alkaline stress, the tracha diameter of root became smaller,the them cortical was gettingthinner, bast fiber lignification degree kept a weak index, lacking of the mechanical tissue ofleaves, the palisade tissue changed into the one of four layers.3. Zaofeng No.5’s pith cells of root increased under the salt stress and the xylemspecialization turned weak, sand and single crystal emerged; Under the alkaline stress, thepith antrum became larger with less catheters and the lignification of catheters were serious.The pith antrum of stems was large under salt stress and small under alkaline stress. The bastfiber lignification degree was strong under salt and alkaline stress, the cell wall wasthickening. The palisade tissue of leaves were increased.4. Jiyu No.59,however, its pith antrum was bigger under salt stress. The lignification ofcatheters was weak, the catheters contain lye and the secondary cell wall was thickeningunder the alkaline stress. Under the salt and alkaline stress, the pith cells of the stem arrangedclosely, the vascular cylinder and catheters increased, the cell wall was thickening obvious under the salt stress, the epidermal hair and protoplasm increased under the alkaline stress.The palisade tissue of leaves increased and arranged closely under the salt and alkaline stress.The physiological results showed that:1. The biomass of two varieties of wild soybeans were decrease under differentconcentrations salt stress and alkali stress. Two varieties (Hui Nan which is salt sensitive andTong Yu which is salt resistant) of wild soybean were treated with60mM or120mM sodiumchloride(NaCl) or alkali (30mM,60mM or90mM NaHCO3and Na2CO3) to induce differentstresses, which were indicated by the responses to photosynthesis and chlorophyllfluorescence. The net photosynthetic rate (Pn), stomata conductance（Gs）and transpirationrates（Tr）of the plant leaves declined when supplied with60and120mM of neutral NaCl, asa stress. Intercellular CO2concentrations of non-salt resistant wild soybean leaves decreasedwith increasing salt concentration. The Ciof salt resistant wild soybeans increased withincreasing salt concentration. The Pn, Gsand Trof non-salt resistant varieties increasinglydeclined with30,60and90mM alkaline salt (NaHCO3and Na2CO3) stress, but the Pnof saltresistant varieties increased slightly with low strength alkaline salts stress. The Ciof two wildsoybeans increased under the alkali stress. There was no obvious change in chlorophyllfluorescence under the salt and alkali stress. The Fv/Fm of non salt resistance wild soybeansunder low salt and alkali stress was also not obvious，While under high salt and alkali stress, itdecreased. The Fv’/Fm’, ΦPSII, ETR and qP all declined under the salt and alkali stress. Thechlorophyll content of the two wild soybeans were decreased under salt and alkali stress, theproline content were increased obviously. The soluble sugar content of wild soybean(Huinan)were decreased under the salt and alkaline stress, but the wild soybean of Tongyu wereincreased.2. The biomass of two varieties of soybeans cultivars were decrease under differentconcentrations salt stress and alkali stress. The net photosynthetic rate (Pn), stomatalconductance (Gs) and transpiration rate (Tr) of the leaves declined with60and120mM of theneutral salt (NaCl) stress. The Pn, Gsand Trof non-salt resistant varieties declined with the30,60and90mM of alkaline salt (NaHCO3and Na2CO3) stress, but the Pnof the salt resistancecultivar increased slightly with low levels of alkaline salt stress. There was no obvious changein chlorophyll fluorescence with low strengths of either salt or alkali stress. Chlorophyllfluorescence parameters, optimal photochemical efficiency of PSII in darkness (Fv/Fm),photochemical efficiency of PSII in the light (Fv’/Fm’) and photochemical quenching (qP)decreased significantly with high strengths of salt and alkali stress.Under the salt and alkalinestress, the chlorophyll content of two soybeans cultivars were decreased compared to thecontrol, and the5th Zaofeng declined more than59Jiyu. The chlorophyll content were decreased, the proline content were increased. The soluble sugar content of soybeanscultivar(Zaofeng No.5) were decreased under the salt and alkaline stress, but the soybeanscultivar of Jiyu No.59were increased.In conclusion, the results showed that the four kinds of soybeans have evolved a seriesof adversity structure under the salt and alkaline stress, which suggested that there was a adirect impact on the morphological structure of plant under the salt and alkali stress and thatTongyu and Jiyu59are more salinity resistant physiologically...