中文摘要：

探讨外来速生红树植物拉关木（Laguncularia rncPmosa）扩张过程中潜在的化感作用，为其入侵风险评估提供参考．通过室内栽培实验测定拉关木根、枝、叶、果的水浸液在不同质量浓度（0．1，0．2，0．3，0．4，0．5 g／mL）下对木榄（Bru-guiera gymnorhiza）幼苗生长的化感作用．结果表明，各器官水浸液对木榄幼苗生长的影响表现为“低促高抑”，质量浓度为0．5 g／mL时，抑制作用最强．各器官水浸液对木榄幼苗生长的抑制作用强弱顺序为：枝〉果〉根〉叶．各器官水浸液对木榄幼苗叶绿素含量均表现为“低促高抑”；木榄幼苗根系活力随拉关木根、叶、果的水浸液浓度的升高呈先升后降的变化趋势，而随枝水浸液浓度的升高，木榄幼苗的根系活力呈下降的变化趋势；丙二醛含量、游离脯氨酸含量和相对电导率大小均随各器官水浸液浓度的升高呈先降后升的变化趋势．

英文摘要：

In order to provide reference for the assessment of invasion risk of fast-growing alien mangrove species of Lagunculariaracemosa ,the aqueous extracts from L. racemosa was used to study the allelopathic effects on growth of Bruguiera gyrnnorhizaseedlings.The seedlings of B. gymnorhiza were investigated in a cultivation with five concentrations （0.1,0.2,0.3,0.4,0.5 g/mL）of aqueous extracts from different organs of L. racemosa.Results showed that the aqueous extracts from L. racemosa had significantallelopathic effects on B. gymnorhiza.The extracts promoted the growth of B. gymnorhiza seedlings at lower concentrations whileinhibited the growth at higher concentrations.The most intensive inhibition was in treatment with 0.5 g/mL of the aqueous extracts.The order of inhibitory effects of different organs of L, racemosa was..stem~ fruit~ root~leaf.The extracts also increased the chlo-rophyll contents of B. gymnorhiza at lower concentrations, while decreased the contents at higher concentrations.With the increasein the concentration of aqueous extracts of root,leaf and fruit of L. racemosa ,the root activity of B. gymnorhiza showed a trend offirst rising and then decreasing.However, with the increase in the concentration of aqueous extracts of stem of L. racernosa, the rootactivity of 13. gymnorhiza showed a trend of decreasing.Moreover, with the increase in the concentration of aqueous extracts of L.racemosa, the MDA contents, the free proline contents in leaf and the leaf relative conductivity of B. gymnorhiza showed a trend offirst decreasing and then rising.