The allelopathic Effects of the Aqueous Extracts from Alternanthera philoxeroides.on the Root Border Cells of Sorghumsu danense(Piper)Stapf.

The air culture method was introduced here to investigate the allelopathic effect of the aqueous extracts from different organs of Alternanthera philoxeroides Griseb,the invasive plant,on the growth of the root,the activity of the root border cells and root cap pectin methyl esterase(PME)of Sorghumsu danense(Piper)Stapf.The results showed that the water-soluble components extracted from Alternanthera philoxeroides had an obvious inhibition and damage effect on the development of root tip of Sorghumsu danense(Piper)Stapf,and the inhibition effect significantly enhanced with the components concentration increased.The survival rate of the root border cells of the Sorghumsu danense(Piper)Stapf decreased with the aqueous extract concentration increased;the activity of PME had a close relationship with the aqueous extract concentration.With the exception of treated with stems extraction,the activity of PME showed a tendency of first increased and then downward,while the opposite trend was showed when treated with stem extraction.The allelopathic effects of aqueous extracts from different organs of Alternanthera philoxeroides Griseb differed significantly,and the allelopathic effects were: leafroot and rhizomestem.The allelopathic effect was the basic mechanism of Alternanthera philoxeroides to perform interference competition,and one of the main reasons to exclude and strangle native species in order to occupy ecological niche quickly.