The Effect Of Light Quality On Accumulating, Distributing Three Medicinal Effective Ingredients Of Astragalus And Tissue Localization Polysaccharide In Astragalus

To discover the suitable light condition for Astragalus to grow, synthesis of active ingredients, increase the production and quality, we use physiological response of plants under stress and secondary metabolism product theory to study the physical signs, major medicinal effective ingredients content and the distribution of Astragalus polysaccharide in root of Astragalus under blue, red, yellow, white and nature light(control) conditions. The result revealed that:(1) the activity of SOD in leaf increased7.4%under yellow light(compare to control); under blue light condition, the leaf presented lowest SOD activity. POD in leaf increased obviously under yellow light condition which increased15.9%compared to control, however there was no significant different between control and blue light condition; the CAT activity had no significant different among four different light condition. The MDA under different light conditions were no the same, but they all increased on October7th and decreased latter, in the end the MDA under yellow light condition was increased38.3%compared to control while under blue light condition the MDA decreased35%which was the lowest among four different light.;(2) blue and yellow light conditions could increase dry matter content and secondary metabolism content effectively, the highest flavonoids specific yield in Astragalus was found in leafs under blue light condition which increased49.2%compared to control. And economic yield under blue light condition was increased56%compared to control. Both highest economic yield and specific yield of polysaccharide or saponin were found under blue light condition, the specific yield of polysaccharide was increased23.9%compared to control, and the economic yield was increased29.4%; the specific yield of saponin was increased94.4%compared to control while the economic yield was increased101%. It was hard to accumulated dry matter under red light condition;(3) the sections of Astragalus revealed that the polysaccharide of Astragalus were main storage in xylem and phloem parenchyma cells, and the polysaccharide could hardly be found in periderm parts, little polysaccharide were found in cambium, lower polysaccharide of Astragalus were found in the place closer to cambium, little polysaccharide of Astragalus were found in central pontine too. The overall analysis revealed that polysaccharide of Astragalus main storage in root phloem of parenchyma cells, it provide science-based for increasing polysaccharide of Astragalus, studying molecular mechanism and controlling the formation of the root structure.