Allelopathic Effects of Artemisia ordosica on Its Seed Germination and Seedling Growth

The allelopathic effects of the ultrasonic aqueous extracts of Artemisia ordosica leaf and litter on its seed germination and seedling growth were investigated using bioassay methods.Sensitivity indices were calculated as well to assess the allelopathic potential of the donor.Results showed that the leaf aqueous extract of A.ordosica inhibited its seed germination and seedling growth,and the inhibitory effects were more obvious at germination stage compared to other tested stages.Germination index was more sensitive to the leaf aqueous extract than germination percentage.The relative conductivity,MDA content,height and root dry weight of seedling were inhibited at seedling stage.The inhibitory effects increased with the concentration of the leaf aqueous extracts.The aqueous extracts of A.ordosica litter inhibited its seed germination slightly,but promoted its seedling growth and the effects increased along with the concentration of litter aqueous extracts.Root dry weight,root length and seedling dry weight were more sensitive to the aqueous extracts at seedling stage.