Investigation On Main Poisonous Plants In Tian Zhu Natural Meadow And Study On Allelochemicals Of Oxytropis Ochrocephala Bunge

Poisonous plants are an important part of the grass in natural grassland ecosystem diversity, maintain the balance of ecological environment. But some poisonous plants can release a lot of allelochemicals into environment and inhibit the growth of forage and cause grass degradation and so on. Surveyed the poisonous plants in natural meadow. Based on Brassica campestris,Avena sativa,Amaranthus retroflexus and Setaria viridis for receptors, studied allelopathy on their main poisonous plants, the allelochemicals form the parts of overground and underground Oxytropis ochrocephala were separated and identificatied,Allelopathic mechanism of Oxytropis ochrocephala was studied in this paper. Inder to make full use of natural grassland poisonous plants, exploit the natural herbicide, utilize natural resources more effectively and sensibly to develop theory. Main results as follows:1. The experiment of toxic plant resources to natural grassland, poisonous plant research totaled 18 families and total of 61 kinds, and 20 specimens of poisonous plant were made .2. By means of bioassay in laboratory and pot-culture method, the results showed that aqueous extracts of the Oxytropis ochrocephala,Artemisia hediniiand Hypecoum leptocarpum had the strongest alleopathy to the four receptor plants,and their synthetic inhibitory effect(M) were -0.7815,-0.6859 and -0.6670,respestively. The synthetic inhibitory effect(M) of Aconitum gymnandium,Elsholtzia densa,Achnatherum inebrians ,Saussurea lappa ,Pedicularis kansuensis ,Sphallerocarpus gracilisand Dracoccephalum heterophyllum were -0.6432,-0.5706,-0.4751,-0.4401,-0.4275,-0.4131 and -0.4129,respestively.While Anaphalis lactea (M -0.3439) and Aconitum szechenyianum (M -0.2625) had a weaker allwlopathy. The living body of Oxytropis ochrocephala had the strongest allelopathy to the four receptors. Their synthetic inhibitory effect(M) were -0.5296,-0.3562,-0.5201 and -0.5884 respestively. Oxytropis ochrocephala had the strongest alleopathy.3. With three different polarity solvents to flower of chrysanthemum spinous Oxytropis ochrocephala were extracted, studied the allelopathy of four receptors. Results showed that the extract of methanol to four receptors on the inhibition was the strongest, the RI values of Brassica campestris was 0.5382; the RI values of Avena sativawas -0.5402; the RI values of Amaranthus retroflexus was -0.7619, the RI values of Setaria viridis also reached -0.4228. Through the overground and underground parts of different concentrations of methanol extracts from Oxytropis ochrocephala on four kinds of receptors, both of them had the strongest impaction.They had an inhibitory effect to the germination and growth of the four receptors.As the same time as reducing the concentration,the impaction had gradually diminished,showed a strong concentration effect.4. The extract of Oxytropis ochrocephala was isolated and purified .Used methanol extraction from the overground and underground part of Oxytropis ochrocephala,then isolated ,purified and identficated by GC/MS. The results showed :the overground part of the components of methylene dichloride (A) identified major sense active substances for fatty acids compounds, methanol series components (F) detection of active substances were fatty acids compounds, most were the series of the relative content hexadecanoic acid methyl ester, for 38.214%, followed by alpha linolenic acid methyl ester and the relative content of stearic acid were 12.392% and 10.826%, Underground part by components (N) identified mainly for tricyclic diterpane and pentacyclic triterpane and showed strong activity, methylene chloride components (A) identification results showed that the main allelochemicals were dicyclohexylmethyl, steroid compound, the content of total cholesterol compounds was 84.183%. Methanol components (F) mainly identified the validity of allelochemicals basking Jiao ketone - 2, and hexadecanoic acid methyl ester, propyl - benzene nonane fatty acid methyl ester compounds tubes chain series. The report about the allelopathic effect ofγ-sitosterol, Ortho-propyl-Methyl nonyl benzene, hentriacontone-16, triacontone-16,Dihydro-N-phenl-ylethylBenzamidesFuranone,Stigmast-diene(2,22)-ketone-6,Stigmast-diene(3,5)-7–ketone,N-phenylethyl–Benzamides,N-B-phenyl–Benzamides,Methyl-C16-Isoprenoid-based–furanone,Basking sharks down-2–ketone, Ferulic acid isooctyl were the initial time in Oxytropis ochrocephala.5. Under extracted liquid pamiricus water of Oxytropis ochrocephala on Avena sativaThe results showed that, with the increase of processing, the content of soluble protein increased, the content of MDA increased significantly, with the increase of the concentration of Oxytropis ochrocephala, the activity of peroxidase (POD) and catalase (CAT) and superoxide dismutase (SOD) were increased.