Water And Salt Handling The Impact On The Quality Of Licorice Herbs

The cultivated herbs were greatly affected by the environmental conditions. How to stabilize and improve the quality of herbs had becoming a hot topic. The researches took Glycyrrhiza uralensis Fisch as material, some aspects were compared, including the growth condition, yield, biological and chemical effects, and chemical constituents within varied water and salty conditions.The influence of water stress on the quality of Radix Glycyrrhizae were revealed, and references for guiding cultivated technique of Glycyrrhiza uralensis Fisch, stabilizing and improving the quality of Glycyrrhiza uralensis Fisch was offered. The main research results were stated as follows:1 water and salty stress had an obvious effect on growth, yield and quality of Glycyrrhiza uralensis. It showed that indexes of the height, diameter, numbers of leafs and biomass was decreased at 40% soil moisture content and 0.3% Salinity. The yield of Glycyrrhiza uralensis had no significant effect at 60~70% Soil moisture content and 0.3% Salinity. The content of glycyrrhizic acid and liquiritin was accumulated at 60~70% soil moisture content and 0.3% salinity.2. The content of glycyrrhizic acid, liquiritin, isoliquiritigenin, total flavone and total saponin were accumulated and the content of Polysaccharide was inhibited at moderate water and salt stress. The contents of glycyrrhizic acid, liquiritin, isoliquiritigenin, total flavone and total saponin in the plant in 40~50% (or 60~70%) water or 0.3% (or 0.6%) salt were obviously higher than those of plant in other treatments. But the content of Polysaccharide was decreased.3. The material composition of the ingredients and the contents of glycyrrhizic acid and liquiritin were changed with water and salt stress. The amount of total sugar was decreased while the amount of crude fiber, crude protein was increased under stress condition. The correlation between the content of glycyrrhizic acid and liquiritin and content of total sugar and ash was negative. The correlation between the content of glycyrrhizic acid and liquiritin and the content of crude fiber was positive.4. The following results were summarized that the content of glycyrrhizic acid and liquiritin was affected under water and salt stress, by regulating glycyrrhizae physiological characteristics for helping Radix Glycyrrhizae adapt to adverse circumstances.①Glycyrrhizae uralensis Fisch could adapt to adverse circumstances by adjusting the content of regulating materials of pervasion (praline, solvable sugar) and increasing the activities of protective enzyme (SOD, POD, CAT, GR)under water and salt stress. The positive correlation between the index of stress tolerance and the contents of glycyrrhizic acid and liquiritin was observed not significantly under water stress, but significantly under salt stress.②Water and salt stress altered indexes of characteristics of photosynthesis change in day. Pn, Tr and Gs all decreased along with the increase of water and salt stress degree. WUE increased along with the decrease of water. The significant positive correlation of Pn and biomass was observed. The improvement of leaf photosynthesis may induce the increase of the contents of glycyrrhizic acid and liquiritin, when the content of water was 20-70%. But a significant correlation between the leaf photosynthesis and the contents of glycyrrhizic acid and liquiritin was not observed under salt stress.③The correlation between the contents of glycyrrhizic acid,liquiritin and N ,P,Ca in organs above ground was positive under water stress and with K,Ca under salty stress.5. Substrates of metabolism and prosoma of glycyrrhizic acid were decreased while the amount of glycyrrhizic acid and liquiritin were increased by enhancing two kinds of key enzymes in synthesis of glycyrrhizic acid under water stress and salt stress, therefore the content of glycyrrhizic acid and liquiritin were increased. This conclusion can be obtained by analyzing that soluble sugar, amylum and the content ofβ- amyrenol has a negative correlation with glycyrrhizic acid under both water stress and salt stress, however , the expression ofβ- amyrenol synthetase and squqlene cyclase were more significant than other treatments .