近年的研究己经揭示出表型可塑性可以通过营养世代遗传.从这个意义上讲,环境诱导的基因调控变化(例如DNA甲基化,即表观遗传变异)会导致可逆的塑性反应传递给后代.这种跨世代的可塑性在克隆植物中尤其重要,因为有性繁殖减少会降低通过遗传变异进行适应的可能性.许多最具侵略性的植物入侵者都具有克隆性,而且克隆性被认为是植物入侵性的关键.本研究中,我们的目标是确定在克隆入侵者喜旱莲子草(Alternanthiera philoxeroides)中是否发生了跨代效应,以及这种效应在本地和非本地群落之间是否存在差异.在同质园实验中,我们将采自巴西(原产地)和伊比利亚半岛(非原产地)的喜旱莲子草种群分别种植在养分高和低的土壤中,后代植株被移植到高养分条件下作为对照.为了检验DNA甲基化对跨代可塑性的潜在作用,一半的母株用去甲基化剂5-氮杂胞苷处理.在来自原产地和非原产地的种群中均观察到了跨代效应.有趣的是,在原产地种群的生长变量(分株数、茎生物量、根生物量和总生物量)中发现了跨代效应,而在非原产地种群中发现了生物量分配具有跨代效应.在原产地种群中出现的跨代效应可以用“银勺”效应来解释,而非原产地种群的跨代效应可以归因于DNA甲基化引起的表观遗传传递.本研究强调了跨代效应对克隆植物生长的重要性,这有助于理解众多克隆植物能够成功繁殖扩张的机制.“,”Aims Recent studies have revealed heritable phenotypic plasticity through vegetative generations.In this sense,changes in gene regulation induced by the environment,such as DNA methylation(i.e.epigenetic changes),can result in reversible plastic responses being transferred to the offspring generations.This trans-generational plasticity is expected to be especially relevant in clonal plants,since reduction of sexual reproduction can decrease the potential for adaptation through genetic variation.Many of the most aggressive plant invaders are clonal,and clonality has been suggested as key to explain plant invasiveness.Here we aim to determine whether trans-generational effects occur in the clonal invader Alternanthera philoxeroides,and whether such effects differ between populations from native and non-native ranges.Methods In a common garden experiment,parent plants of A.philoxeroides from populations collected in Brazil(native range)and Iberian Peninsula(non-native range)were grown in high and low soil nutrient conditions,and offspring plants were transplanted to control conditions with high nutrients.To test the potential role of DNA methylation on trans-generational plasticity,half of the parent plants were treated with the demethylating agent,5-azacytidine.Important Findings Trans-generational effects were observed both in populations from the native and the non-native ranges.Interestingly,trans-generational effects occurred on growth variables(number of ramets,stem mass,root mass and total mass)in the population from the native range,but on biomass partitioning in the population from the non-native range.Trans-generational effects of the population from the native range may be explained by a\'silver-spoon\'effect,whereas those of the population from the non-native range could be explained by epigenetic transmission due to DNA methylation.Our study highlights the importance of trans-generational effects on the growth of a clonal plant,which could help to understand the mechanisms underlying expansion success of many clonal plants.