The Research On The Extraction And The Improvement To Plant Resistance Of Astragalus Polysaccharide

Studies using boiling method, under solid-liquid ratio, solvent extraction, extraction temperature and extraction time in four experimental conditions single factor experiments. By orthogonal experimental design to optimize the extraction process, to optimize the extraction process was obtained with 5% alcohol solution of an alkali as extraction solvent, solid-liquid ratio of 1:10, extraction temperature is 60 ℃. After crude extract of astragalus polysaccharide to protein, to pigments, DEAE- cellulose ion chromatography, dialysis, and ultimately get two kinds of astragalus polysaccharide APS Ⅰ and APS Ⅱ, purity is 93.4% and 91.6%.Tomato seeds and seedlings were treated by Soaking and spraying manner using astragalus polysaccharide, measured seed germination and seedling growth status status. The study found that different concentration astragalus polysaccharide on the tomato seed germination and seedling growth with different role in promoting.10 mg·mL-1 astragalus polysaccharide can improve the tomato seed germination rate,1 mg·mL-1 Astragalus polysaccharide can promote its seedling root elongation and fresh weight and dry weight increasing, And 0.1 mg·mL-1 Astragalus polysaccharide can promote its seedling chlorophyll content.Different concentrations of Astragalus polysaccharide having a certain extent for the four forest pathogens, but the inhibitory effect is not obvious.Only 0.1 mg·ml-1 astragalus polysaccharides on Botryosphaeria dothidea, Septoriapini pumilae and Cytospora chtysosperma bacteria growth inhibition rate was 14.82%,16.08% and 12.16%. And in the 0.01 mg·ml-1 astragalus polysaccharides on Fusarium oxysporum mycelial growth inhibition was 12.63%.In order to study astragalus polysaccharides (APS) on Populus simonii combat the effects of environmental stress ability, through research Populus simonii at low temperature and drought stress conditions in vivo CAT, POD and SOD activity changes, the results show that at low temperature stress, 0.1mg·ml-1 APS can improve the CAT and POD activities and 1 mg·ml-1 APS can enhance the activity of SOD, while 36h later, Populus simonii protective enzymes in APS treated group were lower than in the control group.At drought stress,APS effect on the Populus simonii protective enzyme activity were fluctuating changes, but at 96h, protective enzyme activities of Populus simonii which were treated with various concentrations APS were lower than the control group.Description APS may increase the resistance to environmental stress Populus simonii ability.After Populus simonii being vaccinated Cytospora chtysosperma pathogens, substances content and enzyme activity in Populus simonii relating to the resistance directly marked plant resistance strength. We first sprayed Astragalus polysaccharides to simonii seedlings,then inoculated Cytospora chtysosperma on simonii seedlings and last measured the concentration of active substances and the activities of enzymes in simonii seedlings.Found 0.01mg·ml-1 Astragalus polysaccharides on different times were able to significantly improve soluble protein content and PAL activity in Populus simonii.The total phenolic content in Populus simonii treated by 0.1mg·ml-1 astragalus polysaccharide was significantly higher than the control group.Astragalus polysaccharides improving the content of soluble sugar and chlorophyll in Populus simonii has the best concentration on different time.