Allelopathic Effects Of Ajuga Lupulina And Aconitum Pendulum Of 'Black Soil Patch' Degraded Alpine Meadow On Herding Grasses

Aerba lupulin and Aconitum pendulum were the dominant weed of degraded alpine meadow'black soil patch'in Qinghai-Tibet plateau. In order to explain the formation and spreading mechanism of'black soil patch'dominant weed, and provide academic base for vegetation choice of regeneration of'black soil patch',this paper studied the allelopathy of aqueous extracts of Aerba lupulin and Aconitum pendulum on seed germination and seedling growth of four fitting growth herding grass species. The main results are as follows:The allelopathy of Aerba lupulin on seed germination and seedling growth of four herding grass species was stronger than Aconitum pendulum. The aqueous extracts of Aerba lupulin and Aconitum pendulum had allelopathy inhibition to four herding grasses(Poa crymophila, Festuca sinensis, Elymus sibiricus, Elymus nutans), and the concentration was more high ,the inhibition was more obvious, when the aqueous extracts concentration reached 40g/L, they had very distinct allelopathy inhibition to seed germination.The aqueous extracts of Aerba lupulin and Aconitum pendulum both had different allelopathy inhibition to four herding grasses, the allelopathic sensitivity to Aerba lupulin was in the order of Elymus nutans.> Elymus sibiricus > Poa annua > Festuca sinensis, the allelopathic sensitivity to Aconitum pendulum was in the order of Poa annua.> Festuca sinensis > Elymus.sibiricus > Elymus nutans. So during vegetation recovery course of degraded alpine meadow'black soil patch', Festuca sinensis could be used as preference at Aerba lupulin'black soil patch'type, Elymus nutans could be used as preference at Aconitum pendulum'black soil patch'type.The allelopathy of aboveground aqueous extracts was more stronger than belowground, different organic allelopathy sensitivity of Aconitum pendulum was in the order of leaf aqueous extract > stem aqueous extract > root aqueous extract, which showed there were differences in different organic of one plant., it was may caused by aboveground of Aerba lupulin and leaf of Aconitum pendulum had much more and stronger allelopathy material.Comparing the two growing periods, the sensitivity of seedling growth was weaker than seed germination, and germination index was most obvious to be affected by the allelopathy inhibition. The aqueous extracts of Aerba lupulin and Aconitum pendulum both had inhibition to root length and seedling height, and root length was more obvious to be affected than seedling height, which showed root length was more sensitivity to allelopathy.The aqueous extracts of Aerba lupulin aboveground and Aconitum pendulum leaf both had very distinct or distinct inhibition to chlorophyll content of herding grasses leaf .With the allelopathy intimidation of Aerba lupulin and Aconitum pendulum, the concentration of aqueous extracts was more high ,the MDA content was also more high. It indicated herding grasses occurred membrane lipid peroxidation under allelopathy intimidation, which caused MDA content of plant increase.The aqueous extracts of Aerba lupulin and Aconitum pendulum had distinct allelopathy inhibition to the local graminaceious herding grasses. Therefore eluvation and plant dissolution may were the important ways for bringing allelopathy inhibition. The releasing of allelopathy inhibition material was the important factor of poisonous weed growing, good herding grasses decaying, and'black soil patch'coming into being ultimately. So suggest in the measure of regeneration of"black soil patch"should notice the disposal of poisonous weed.