Allelopathic effects of extracts from Solidago canadensis L.against seed germination and seedling growth of some plants

To investigate the potential role of allelopathy in plant interference and in the successful invasion of alien species Solidago canadensis, aqueous and ethanolic extracts from rhizomes, stems and leaves of S. canadensis were prepared and used as treatment solutions to assess their effects on seed germination and seedling growth in four target species, mulberry （Morus alba）; morning glory （Pharbitis nil）, wheat （Triticum aestivum） and rape （Brassiea campestris）. Reduction and/or growth in germination and growth of the target plant species in the presence of both aqueous and ethanolic extracts at different concentrations indicated that the responses were species-specific and concentration-dependent. Generally, ethanolic extracts （especially from leaves） imposed stronger effects on both seed germination and seedling growth. Extracts with lower concentration at 0.001 g/ml dw could stimulate the seedling growth of rape and morning glory, whereas extracts at any given concentrations have inhibitory effects on wheat and mulberry. It is suggested that the aqueous and ethanolic extracts of all the three parts of S. canadensis have significant allelopathic effects. Although both inhibition and stimulation occurred in the germination and growth of the target species, extracts with higher concentrations definitely inhibit seed germination and seedling growth of all target plants. We suggest that allelopathy plays a more important role than other mechanisms do in the out-competition ofS. canadensis over other plants, and make it invasive in new habitats.

Allelopathic effects of extracts from Solidago canadensis L.against seed germination and seedling growth of some plants

To investigate the potential role of allelopathy in plant interference and in the successful invasion of alien species Solidago canadensis, aqueous an d ethanolic extracts from rhizomes, stems and leaves of S. canadensis were prepa red and used as treatment solutions to assess their effects on seed germination and seedling growth in four target species, mulberry (Morus alba); morning glory (Pharbitis nil), wheat(Triticum aestivum) and rape(Brassica campestris). Reducti on and/or growth in germination and growth of the target plant species in the pr esence of both aqueous and ethanolic extracts at different concentrations indica ted that the responses were species-specific and concentration-dependent. Genera lly, ethanolic extracts(especially from leaves) imposed stronger effects on both seed germination and seedling growth. Extracts with lower concentration at 0.00 1 g/ml dw could stimulate the seedling growth of rape and morning glory, whereas extracts at any given concentrations have inhibitory effects on wheat and mulbe rry. It is suggested that the aqueous and ethanolic extracts of all the three pa rts of S. canadensis have significant allelopathic effects. Although both inhibi tion and stimulation occurred in the germination and growth of the target specie s, extracts with higher concentrations definitely inhibit seed germination and s eedling growth of all target plants. We suggest that allelopathy plays a more im portant role than other mechanisms do in the out-competition of S. canadensis ov er other plants, and make it invasive in new habitats.