Effects Of Root Extracts From Artemisia Frigida Willd On Seeds Germination And Seedlings Growth Of Several Pasture Plants

The reports confirmed that the shoot extracts and VOCs from Artemisia frigida willd have allelopathy and provided the basic theory for the mechanism of easy to form a single community in the process of grassland degradation. In order to find out the allelopathy of the roots of A .frigida, the study analyzed the aqueous extract and methanol extract from fresh roots and dried roots of A .frigida using GC/MS and investigated seed germination and seedling growth of Agropyron mongolicum, Elymus dahuricus, Elymus sibiricus and Melilotus officinalis under the aqueous extract and 50% methanol extract from roots of A . frigida using bioassay. The results were as follows:1. Analyzed by GC/MS, the aqueous extract from fresh roots of A .frigida mainly contained Azulen-2-ol,1,4-dim-ethyl-7-methylethyl-,Cantharidin,Tridecanoic acid,Undecylenic Acid,Danthron,Menadione,Eucalyptol,1-Undecanol,Chloroxylenol,Vanillin,Phenol,p-tert-butyl-,Eugenol,n-Hexadecanoic acid,Octadecanoic acid and Testosterone etc eleven kinds of substances, they contented 77.42 percent of total; the aqueous extract from dried roots of A .frigida mainly contained Azulen-2-ol,1,4-dimethyl- -7- methylethyl-,Tetradecanoic acid,Testosterone,Menadione and Testosterone etc five kinds of substances, they contented 94.99 percent of total; the methanol extract from fresh roots of A .frigida mainly contained Azulen-2-ol,1,4-dim-ethyl-7-methylethyl-,Eucalyptol,Cantharidin,Undecylenic Acid,1-Undecanol,Azelaic Acid,Vanillin,Mequinol,Tridecanoic acid and Hydroquinone etc ten kinds of substances, they contented 73.86 percent of total; the methanol extract from dried roots of A .frigida mainly contained Azulen-2-ol,1,4-dimethyl-7- methylethyl-,Tridecanoic acid,Oleyl Alcohol,Cantharidin,Chloroxylenol,Menadione,Danthron,Undecylenic Acid,Mequinol and Eucalyptol etc ten kinds of substances, they contented 86.51 percent of total.2. With the concentration increasing of the extracts from roots of A . frigida, the germination of four kinds of plants gradually reduced. Under the action of the 50 mg·mL-1 aqueous extract of A. frigida, so that the inhibition rate of seed germination of A.mongolicum,E. dahuricus,E. sibiricus and M. officinalis was 65.09%,44.59%,34.23% and 52.45%, the bud length decreased by 57.12%, 34.61%, 26.90% and 39.53%, respectively, the root length reduced 58.55%, 57.91%, 69.65% and 48.26%, In biomass allocation the root was more inhibited than the bud; At the same concentration, the inhibition of germination and growth of four kinds of plants increased significantly under the methanol extract from roots of A . frigida.3. The content of chlorophyll was reduced, and photosynthesis was changed by the extracts from roots of A. frigida. The activity of SOD was increased firstly then decreased; the activity of POD, the activity of CAT, The content of MDA and the activity of root were increased. These reflected the regulation of tested plants and the inhibition to the tested plants.The results of this study proved that the roots of A. frigida could produce allelopaticals, the allelopaticals effected on other grass and provided another basic theory for the mechanism of to form a single community easily in the process of grassland degradation.