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Ginseng (Panax) is a perennial herb Araliaceae, with qi and yin, the effect of heat fluid is precious tonic herbs, ginseng cropping obstacles but more prominent, showing old ginseng growers participants happen again participate Root burning beard, sickly and difficult seedling plants and other phenomena, resulting in low yields, poor quality, affecting its economic benefits. Ginseng has been a continuous cropping of attention problems, many researchers on old ginseng microbial community changes and changes in soil properties were studied, and ginseng own chemicals on the growth of the important factors have been overlooked. In order to reveal the mechanism of ginseng cropping obstacles and find with allelopathy from toxic chemicals, the authors followed by the use of methanol, ethyl acetate, n-hexane three different polar organic solvent extraction agent, extracted from ginseng Houtu organic ingredients of different polarity, wherein the extract from the 20% methanol solution 23 substances were identified, belonging alkanes, aromatics, alcohols, aldehydes, acids, esters, such as different classes. The comparison with the literature most of these substances are allelochemicals, where three kinds of aldehydes, which is 2 - methylpentanal 2 - methyl - hexenal 7 - sixteen enal in the past have not been reported in the literature, There may be specific reference soil substances. In methanol as the extraction agent in the sample, a total of seven kinds of active substances identified (matching the index of 800 or more). In addition to PCNB as pesticide residues, the other ingredients belong esters three kinds, the total content of about 10.9%, organic acids 1 species, accounting for 78.8%, ketones 1 species, accounting for about 3.1%, amines 1 species, accounting for about 1.0%. Wherein the total content of bitter substances in 78.8% of the methanol content of ginseng extract soil has an absolute advantage, indicating bitterness of ginseng produced important component of the allelopathic. According to Rice allelochemicals classification theory determine parameters Houtu methanol extract of the other two substances or 8 - fifteen and thirteen carbonic acid methyl ketone should be allelopathic substances, but in other plant allelochemicals study did not reported that there may be unique to ginseng allelochemicals. The ethyl acetate extracts from ginseng Houtu CCP identified 43 kinds of ingredients. These ingredients are fat alkanes were 10 species, nine kinds of aromatic hydrocarbons, ketones three kinds, three kinds of alcohols, acids six kinds, esters 12 kinds, each substance ingredients scattered distribution, by comparison with the literature, most are based allelochemicals species. Participation Houtu hexane extract most of the organic ingredients are alkanes, and polar weak. This is related to the selected solvent. Also shows a lot of reference soil organic ingredients are weakly polar substances, can be weakly polar solvent extracted. The analysis shows that in the n-hexane extract of soil parameters, there are 15 kinds of alkanes, esters three kinds, five kinds of other substances. Matter more. But the species is relatively small. Content distribution is scattered, effective identification of the substance in its content of 1% or less. As can be seen from the experimental results of different polarity solvent extracted material composition vary greatly, so that only can be achieved with the use of a more comprehensive extraction. If you ignore them which will lose some valuable substances. The study also collected using the sand culture method hawthorn ginseng root exudates of organic ingredients, linked by GC-MS method combined with biometrics chemical composition of the samples were analyzed and identified. The results from various solvent extraction samples isolated and identified a variety of organic compounds, the literature, the majority of these organic ingredients are allelochemicals Another innovation of this paper is the first decomposing residues in ginseng liquid ingredients for effective analysis, the results confirmed the participation in the decomposing body of the existence of a variety of allelochemicals, which was the highest percentage of bitterness, which participate in the methanol extract of soil bitterness highest concentrations formed a causal explanation bitterness of ginseng allelochemicals produced by one of the major components, and most accumulation and rhizosphere soil of. Participation also found decomposing body fluid in the n-hexanoic acid, n-heptanoic acid, 2 - methyl - hexanoic acid allelopathic in previous studies have not been reported in the literature, so there may be unique to ginseng allelochemicals.
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