入侵植物喜旱莲子草预培养土壤对自身及同属本地植物生长的影响及机制

植物-土壤反馈可以在一定程度上阐明入侵植物入侵及维持的机制.通过比较入侵植物喜旱莲子草（Alternanthera philoxeroides）预培养的土壤与本地植物莲子草（Alternanthera sessilis）预培养的土壤对入侵植物喜旱莲子草与本地植物莲子草生长的影响，从土壤肥力、微生物群落及化感物质等角度阐明喜旱莲子草入侵过程中的植物 土壤反馈作用及可能机制，为入侵植物入侵机理的阐明提供理论依据.喜旱莲子草预培养土壤与莲子草预培养土壤对自身及彼此的叶生物量、茎生物量、根生物量和总生物量均无显著影响.喜旱莲子草预培养土壤的碱解氮显著高于莲子草预培养土壤，但是2种土壤肥力对喜旱莲子草以及莲子草的生物量均不存在显著相关.喜旱莲子草预培养土壤经灭菌处理后可以显著地促进莲子草的根生物量、茎生物量及总生物量，显著地抑制莲子草的叶生物量，但对喜旱莲子草的生长无显著影响，表明喜旱莲子草预培养土壤中的微生物群落对莲子草的生长具有一定的抑制作用.喜旱莲子草预培养土壤经添加活性碳处理后对喜旱莲子草与莲子草的生物量均无显著影响，表明喜旱莲子草预培养土壤中的化感物质对莲子草的生长不具有显著作用.

Effect of Alternanthera philoxeroides-primed soil on the growth of itself and congeneric native Alternanthera sessilis and the possible mechanisms

Plant-soil feedback plays an important role in the invasion success and maintaining of the invaded commu- nity. Here, we compare the effects of invasive A. philoxeroides-primed soil and congeneric native A. sessilis- primed soil on the growth of invasive A. philoxeroides and native A. sessilis and analyze the roles of soil fertility, soil microbes and allelopathic chemicals in the effects of A. philoxeroides-primed soil on the growth of both A. phi- loxeroides and A. sessilis. We aim to find out the plant-soil feedback mechanism during the invasion of Alternan- thera philoxeroides. There is no significant effect of A. philoxeroides-primed soil on the leaves, stems, roots and total biomass of both A. philoxeroides and A. sessilis. The available nitrogen content in A. philoxeroides-primed soil is significantly higher than that in A. sessilis-primed soil. But there is no significant relationship between the plant biomass and soil fertility. Sterilization of A. philoxeroides-primed soil could significantly increase the roots, stems and total biomass of A. sessilis and decrease the leaves biomass of A. sessilis, while has no significant effect on the growth of A. philoxeroides. This indicates that the soil microbes in invasive A. philoxeroides-primed soil might have inhibitory effects on the growth of native species. Addition of activated carbon A. philoxeroides-primed soil has no significant effects on the growth of native A. sessilis, indicating that the allelopathic chemicals in invasive A. philoxeroides-primed soil might have no significant effect on the growth of native species.