Allelopathic Effects of Aquatic Extracts from Solidago canadensis's Roots and Rhizospheric Soil on the Seed Germination and Early Seedling Growth of Chinese Cabbage and Radish

The allelopathic effects of aquatic extract from S.canadensiss roots and rhizospheric soil on the seed germination,root extension and elongation of seedlings of Chinese Cabbage and Radish were studied in this paper.Results showed that aquatic extract from roots and rhizospheric soil generally inhibited selected seed germination.Aquatic extract from rhizospheric soil stimulated elongation of seedlings of Chinese Cabbage and Radish,and had significant allelopathic effects on elongation of radicle extension of both species.Aquatic extract from roots stimulated radicle extension of Radish seedlings at 0.05 g/mL,but had no effect on both species at other selected concentrations.Results obtained in this study also showed the trend that the aquatic extract inhibited the root dehydrogenase activity and nitrate reductase activity of early seedlings of Chinese Cabbage and Radish at high concentrations.