Study on the Allelopathy of Ipomoea purpurea on Cabbage Seed

Ipomoea purpurea was an invasive alien plant.The allelopathy played an important role in alien plant invasion.By means of laboratory bioassay,the allelopathic effect of water extract from Ipomoea purpure on seed germination and seedling growth was investigated using four cabbage varieties.The results showed that the germination seeds of cabbage were affected by different concentration of the water extract.Lower concentrations could increase the germination percentage of Fengkang 78 and Jinlu 75 and the inhibitive rates were-12.4%——1.1%.With the water extract concentration increasing,the effect became inhibition which showed enhanced trends with the inhibitive rates 9.7%-27.2%.The water extract decreased the germination percentage of Xiyou 78 and Zaoshu 5.Most water extract could restrain the growth of roots and the inhibitive rates were 12.5%-77.4%.Lower and middle concentrations could increased the height of seedling and the inhibitive rates were-47.5%——5.3%.Wtih the water extract concentration increasing,the promtion effect was weakened and even became a inhibition effect,with the inhibitive rates of 9.10%-31.60%.Zaoshu 5 showed relatively stronger resistance.