Abstract:

It is known that the allelopathy plays an important role in the successful invasion of crofton weed Ageratina adenophora Sprengel. But, we knew little about the relationship between A. adenophora’s allelochemicals and native plants in the medium of soil. In this study, the effects of aqueous leaf extract of A. adenophora on germination rate (GR) and germination time (GT) of Dactlis gloerata L. were determined with different concentrations of the extract by using the modified filter paper – Petri dish method. Besides, the changes in seedling growth and the activities of anti-oxidative enzymes were measured in early growth stages. The results showed that the GR was significantly affected by the high concentration of the extract. Seedling height and biomass decreased significantly with the increased concentration of the extract in the early stages. However, they were not significant in the late stages. The activities of anti-oxidative enzymes varied significantly among different treatments. At the lower concentrations, the activity of POD did not vary very much among different treatment periods, but the activity of CAT varied remarkably. In contrast, at the higher concentrations, the activity of POD varied obviously, but the activity of CAT did not vary significantly. At the beginning of the treatment, the activity of SOD varied significantly, but such difference decreased with the increase of treatment time. The results of this study have provided some theoretical guidance for replacement control of A. adenophora.