The Study On Content Of Main Organic Acid On Seedling Of Malus Hupehensis Rehd. Under Continuous Cropping Conditions

To study the effect of the content of main oraganic acids on seedling of Malus hupehensis Rhed. The experiment was conduct from January2012to April2014in College of Horticulture science and Engineering of Shandong Agricultural University and State Key Laboratory of Crop Biology. The soil samples were take from DaoLang Town and CiYao Town, Tai’an City, Shandong Province in April2013. In pot Laboratory experiment, Malus hupehensis Rhed. was used as material to study the impact of organic acid and alkaloid on photo synthetic indexes, biomass, protective enzyme in leaf and root, root activity, root morphology index (root length, root volume, root superficial area, tip number) and soil microbial environment (bacteria, fungi, actinomycetes), available nutrient in soil (nitrogen, phosphorus and potassium). The main results are as follows:1、The study put forward a new method to extract orange acid in soil. The optimum conditions is that:pressure,10.3MPa(=1493.5Psi); temperature,60℃; dwell time,6minutes; purge volume,60%; purge time,200s; the static cyclic, twice; extraction solvent,0.2%phosphoric acid solution; Filter membrane, glass fibre.2、The main organic acid in replant soil is oxalic acid, tartaric acid, citric acid, malic acid. The concentration of the above four kinds of acids are that, oxalic acid,0.0394～0.2393mg/g; tartaric acid,4.163-37.2612mg/g, citric acid,0.1763～0.8167mg/g, malic acid,0.2989～0.95mg/g. The largest proportion among them is tartaric acid up to70.88%-97.98%. The content of different kind of organic acid in replant garden and old garden, the result show that the content of oxalic acid in replant garden is more than that in old garden significantly in DaoLang;the content of oxalic in the two kind of soil mentioned above is almost the same.The same principle also in tartaric acid.3、Different kind of organic acids show different effect on Physisoloqical property on seedlings of Malus hupehensis Rehd.. Compared to the control, the treatment of oxalic acid improve the Net photosynthesis rate, Intercellular CO2concentration, Stomatal conductance, Transpiration rate remarkably, separately by32.27%、28.17%、76.58%、41.13%, the dry weight, fresh weight, separately by24.12%、35.72%. And contrary to the results of the treatment of oxalic acid, the treatment of tartaric acid reduced the above indexes. The treatment of tartaric respectively reduced Net photosynthesis rate, Stomatal conductance, Transpiration rate by8.00%、12.69%、10.27%、dry weight, fresh weight by2.21%、3.38%.Treatment of citric acid and treatment of malic acid have effect on the above indexes, but there is no regularity.4、In pot experiment, we determated the content of the four kinds of organic acids in soil samples for twice. In the control group, with the passage of the exerimental, we can find out that the content of tartaric acid is more stable than the content of other three kinds of organic acid. However, the content of oxalic and tartaric acid showed a downward trend. On the other hand, the content of crtric acid showed a upward trend.After the treatment of oxalic acid, tartaric acid, citric acid, malic acid and the mixture of the above four kinds of organic acids, the soil environment changed greatly. The treatment of oxalic acid improves the bacterial fungal ratio by160.07%compare to the control. And contrary to the results of the treatment of oxalic acid, the treatment of tartaric acid reduces the bacterial fungal ratio by36.40%.5、The determination of the concentration of alkaloids. This experiment uses three different solvents by methyl alcohol,20%hydrochloric acid solution, acetone with the method of sonic oscillation and Accelerated Solvent Extraction to extract alkaloids in the soil. Through the contrast experiment, we find out that extract alkaloids in the soil’ by20%hydrochloric acid solution with the method of SPE-RRLC-Q-TOF show the best effect. In this study, we separated and detection3kinds of alkaloids, they are Harmaline, Cinchonine and Galanthamine.