In the study,Conyza bonariensis that collected from natural agricultural plant communities is taken as the donor,and typical dicotyledonous Vicia faba and typical monocotyledonous Zea mays seedlings as receptors.Micronucleus test and chromosome aberration test are used to investigate the genetic toxicity of aqueous extracts of different organs of C.bonariensis on the receptors.The results show that:(1)In the aqueous extracts of C.bonariensis,both root tip cells of V.faba and Z.mays in each phase of mitosis are significantly affected,which appear micronucleus,chromosome bridge,chromosome fragments,chromosome rings,lagging chromosomes,chromosome adhesions and other chromosomal aberrations;(2)The division inhibition effect of aqueous extracts from different organs of C.bonariensis on seedling root tip cells of V.faba is significantly greater than that of Z.mays;(3)Chromosome aberrations of V.faba and Z.mays root tips induced by aqueous extracts of C.bonariensis present a significant concentration-dependent effect:the higher the concentration of the aqueous extracts,the higher the receptor micronucleus rate and distortion rate,and the lower the corresponding mitotic index,which show that the mutagenic effects of the aqueous extracts and concentration is positive correlation,but not a simple additive effect;(4)All the aqueous extracts from C.bonariensis have strong genetic toxicity,however,the whole performance of the allelopathic effects from the organs is leaf>fruitlet>stem>root.We suppose that the reason C.bonariensis successfully invade new habitats is that its secreted allelochemicals impact on mitosis and cell morphology of the growing point of receptors,resulting in a variety of chromosome aberrations and irreversible genetic damage.