Abstract: Oxytropis glabra is a poisonous perennial herbaceous plant,it can become the dominant weeds on degenerated pastures. Melilotoides ruthenica,Astragalus Melilotoides and Agropyron mongolicum are the common high-quality forage grasses in grasslands. In this paper,O.glabra was taken as the donor plant to study the effects of aqueous extracts from roots,stems and leaves with different concentrations on seed germination of 3 receiver plants. The results show that there was an allelopathy of aqueous extracts from the stems,leaves and roots of O.glabra on the seed germination rate,germination index,plumule length and radicle length of the plants. The allelopathy of the two kinds of aqueous extracts on the germination index was higher than on the seed germination rate,and that on the radicle length was higher than on the plumule length. Allelopathy of different donor parts to the different receiver plants was significantly different,and that of the aqueous extracts from stems and leaves was higher than that from roots. Results showed that the allelopathic sensitivity of the three receiver plants to the two kinds of aqueous extracts was in an order of A.mongolicum>A.melilotoides>M.ruthenicus. The effects of two kinds of aqueous extracts with different mass concentrations on the receiver plants revealed that the higher the concentration was,the stronger the allelopathy would be. The inhibition of aqueous extract with high mass concentration (≥10 mg·mL^-1) was significant,but that with low mass concentration (≤5 mg·mL^-1) was not significant.

Key words: Oxytropis glabra, aqueous extract, allelopathy, seed germination