Abstract: The allelopathy of aqueous extracts of Magnolia denudate，Pterocarla stenoptera，Prunus cerasifera，Viburnum macrocephalum，Syringa oblata，Bischofia polycarpa on seed germination and seedling growth of Triticum aestivum，Raphanus sativus and Brassica chinensis were studied indoors using a biological monitoring method. Results indicated that the six garden trees all exhibited strong allelopathic inhibition on crops. And， the allelopathic inhibition on seedling growth was greater than on seed germination. The six garden tree species significantly inhibited root length and seedling height of the three crops under the treatment of 00125 g·mL-1 extracts，and the root length and seedling height were fully inhibited under 01 g·mL-1 extracts. Synthesize effects of the six garden tree species were between 30%～80%. Overall allelopathy of the six garden tree species decreased in the order of Syringa oblata>Viburnum macrocephalum>Bischofia polycarpa>Magnolia denudate> Pterocarla stenoptera > Prunus cerasifera. These results indicated great development potential of the six garden tree species.

Key words: garden tree species, crops, allelopathy, seed germination, seedling growth