Allelopathic interactions between invasive plant Solidago canadensis and native plant Phragmites australis

Taking the seeds of invasive plant Solidago canadensis and native plant Phramites australis from their mono-and co-dominant communities as allelopathic acceptors,this paper analyzed the differences in the seed germination rate and sprout length after treated with five level(12.5,25,50,100,and 200 mg·mL-1) S.canadensis and P.australis extracts,aimed to understand the allelopathic interactions between the two species.The 1000-grain weight and seed germination rate under distilled water treatment of the two species in co-dominated community were greater than those in mono-dominant community.Low level(12.5 and 25 mg·mL-1) S.canadensi extracts slightly promoted the seed germination rates of S.canadensis in both mono-and co-dominant communities,but high level(50,100,and 200 mg·mL-1) S.canadensi extracts had strong inhibition effect,especially for the S.canadensis in co-dominated community.No significant patterns were observed about the effects of P.australis extract on S.canadensis seed germination.The sprout length of S.canadensis seeds in both mono-and co-dominant communities decreased with increasing level of S.canadensis extract,but decreased in a fluctuation way with increasing level of P.australis extract.After treated with the extracts of P.australis or S.canadensis,the seed germination rate of P.australis in mono-dominant community was significantly greater than that in co-dominant community(P 0.05),but there was no significant difference between these two extracts.