Releasing Mode And Isolated And Identified Of Main Allelochemicals From Osytropis Ochrocephala.L

Oxytropis Ochrocephala was a hebaceous and poisonous plant which had been called Ma Chang Cao. The plant mainly distribute in the northwest natural grass field of China, amd also in north and southwest China. If animals eat it, this plant will not only make chronic poisoning and addition, but also can cause severe loss in animal husbandry. Prior study had confirmed that Oxytropis Ochrocephala has strong allelopathy activity. In order to use Oxytropis Ochrocephala to develops new and provide basis theories of no harm herbicide, this paper inquiry preliminary on Oxytropis Ochrocephala releasing mode , demonstrate the relationship between root path and root soil microorganism, isolate and identify the main components of Oxytropis ochrocephala. Main result of this paper list were as follows:The 4 kinds of releasing modes of Oxytropis Ochrocephala were test on Avenasa tivaoats.L, Brassica campestris.L, Elymus nutans.L and Chenopodium album.L as receptor plants by by indoor bioassay.The result showed that overground part aqueous extract,volatile matter, root exudates and residues of Oxytropis Ochrocephala have allelopathy activity to 4 Receptor plants inordinately.Through the comprehensive comparison of allelopathy. The SE value of 4 kinds of releasing modes to 4 kinds of receptor plants are -1.1467, -0.4290, -0.0268 and -0.3071 respectively. This means that allelocohemicals of Oxytropis Ochrocephala existed in the underground part, and mainly release allelocohemicals to the surrounding environment by root exudates ,the following were overground part aqueous extract ,residues. Allelopathy activity of volatile mode was weak.2. Through the allelopathy activity test of different density root exudates of Oxytropis Ochrocephala to receptor plants ,the result showed that : The differrence between density processing and receptor plants processing are significant differences. The allelopathy activity of different density root exudates to receptor plants are opposite with the density of Oxytropis Ochrocephala. The inhibiting effect of Chenopodium album is strong enough under the same density. The value of M is -0.4682 when the density is 0.1g/ml and the influence to root is stronger than seedings. Through the comparately analysis of root exudates and root soil microorganisms, we find that root exudates not only relase allelocohemicals to surrounding by Oxytropis Ochrocephala , but also relevant with the existence of root soil microorganism.3.Through isolated and purified the extract of Oxytropis Ochrocephala by hexane(N),dichloromethane(A) and methanol(F),we had got 3 extractions from the root of Oxytropis Ochrocephala and the allelopathy activity of the extractions were test with Brassica campestris L. The results showed that: the extractions have allelopathy activity but the weak-polar extraction's and the intensive polar's extraction were stronger.The value of M is 0.5771,-0.4107.Through identified by GC-MS, the components in hexane(N) were alkanes and the concentration of allelocohemicals was low. The major components in methylene dichloride(A) were fatty acids and the serise methanol components, there are 70% substances showed actived. They were 9,12-Octadecadienoic acid, methyl ester,(Z,Z) (C19H34O2), 9,12,15Octadecatrienoic acid, methyl ester,(Z,Z,Z)–a(C19H32O2), Stigmasterol,22.23-dihydro (C29H50O). The major components in methanol components(F)mainly were basking Tetradecanoic acid, methyl ester (C15H30O2) pentadecanoic acid and methyl ester (C16H32O2) have strong allelopathy activity.