摘要

Allelopathy may play an important role in the invasion success of alien plant species. In this study, we examined the effects of aqueous extracts from the leaves and roots of the invasive plant species Chromolaena odorata (L.) King and Robinson at different concentrations (control, 1%, 5%, and 10%) on the seed germination and seedling growth (root and shoot length) of 10 herbaceous species using the Petri dish bioassay. The 10 herbaceous species comprised five native and five non-native invasive species all common in most habitats in southern China. C. odorata leaf and root extracts inhibited the seed germination, root length, and shoot length of most target species at different concentration levels. This inhibitory effect generally increased with increased extract concentration, and was more pronounced with the leaf extract than the root extract. There were more obvious inhibitory effects on the five native species than the non-native ones, suggesting that the latter had co-evolved with C. odorata in their native range (South America) and were relatively less susceptible to allelopathic compounds released by C. odorata. These results suggested that allelopathy may contribute to the ability of C. odorata to become dominant in invaded plant communities in southern China.