The Research Of Allelopathic Activity And Environmental Behavior Of Organic Acid Of Ginseng Rhizosphere

The bottleneckproblem of Ginseng planting industry development was continued cropping obstacle. The new starting point of researched causes and mechanism is the viewof allelopathic effectscurrently.Phenolic acids in root secretion was a significant allelopathic activity of the material. According to the result of this topic research,the amount and type of organic acids of ginseng continuous cropping soil were dramatic changed. Therefore, the context was to explore the allelopathicactivity,interaction and environmentalbehavior of root exudates of ginseng.The main research results were showed as follow:1. Allelopathy of 11 kinds of organic acid found in soil was analyzed to determine the main allelochemicals. The result showed that the inhabitation and promotion activity of benzoic acid and adipic acid, lactic acid was strongest. With the RI value-0.73、0.61.2.The interaction effect of lactic acid with the rest of the allelochemicals was mainly antagonism,named after the mixure of the two, the original activity was reduced,with the lactic acid and oleic acid for the proportion of 1:100, showing the strongest antagonistic activity.3.By comparing the influence of different soil on the migration of benzoic acid,Rf value were 0.50, 0.67, respectivelyIn addition to ginseng in the center area, its strong allelopathic activity influence area for 6-8 cm from ginseng root(new forest soil), 8 to 10 cm(old and). Forest soilis stronger adsorption capacity, weaker desorption capacity and smaller bearing capacity then the ginseng-grown land soil of benzoic acidWhen the content of benzoic acid over 1.07 mu g/g in the soil, biomonitoringindicated lettuce can be showed remarkable allelopathic inhibition effect.4.The adsorption and desorption behavior of benzoic acid in the cropped soil was studied. The results showed that the saturation adsorption time of the soil to benzoic acid was 16-36 h, the adsorption rate was 84.67%-91.18%; The diffusion model of benzoic acid in the adsorption kinetics of soil was simulated well.(r>0.7); The thermodynamic process was accorded with the equation of Fruendlich isothermal adsorption. The adsorption of benzoic acid in soil was belonged to physical adsorption, and the high concentrations of benzoic acid molecules in the soil particles were dominated by the bound state.5.TheGC- MS analysisof ginseng callus metabolites under aseptic condition collected, the results showed that: The secondary metabolites of ginseng callus secretion were detected 26, mainly for sugar, acid, alcohols, ketones, aldehydes, including sugar as main ingredients, a total of 12 species, followed by 7kinds oacid. There is considerable difference of ginseng root secretion between collecting with aseptic conditions and collecting in field. We should pay great attention to the transformation of environmentin analysis of ginseng allelopathy.