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野外和同质生物园比较经常用于研究入侵植物快速进化.当原产地或引入地的种群地理分布范围较广时,表型性状的纬度渐变可能会影响这种比较分析.我们检验了纬度渐变是否会影响欧洲千里光(Senecio vulgaris)引入地和原产地种群间的比较.欧洲千里光原产于欧洲,现已引入到中国东北和西南地区.我们对欧洲原产地和中国引入地的野外种群进行了调查,同时在瑞士开展了同质生物园实验,比较了中国引入地种群与欧洲原产地种群的株高、分枝数和花序数,以此衡量两地欧洲千里光种群在生长和繁殖方面的差异.野外调查表明,中国引入地种群的株高和花序数量显著大于欧洲原产地种群,这一结果与增强竞争力进化假说的预测一致.在同质生物园比较中,当考虑纬度渐变的作用时,中国种群的花序数量显著大于欧洲种群.分别将中国东北部、中国西南部两个地区的种群与欧洲种群进行比较,无论在野外还是同质生物园,与欧洲种群处于相似纬度的中国东北部种群表现出更高的株高和更多的花序.但位于更低纬度的中国西南部种群的繁殖表现并不强于原产地种群.因此我们的结果表明,当引入地种群地理分布较广时,无论野外还是同质生物园的比较都应该考虑表型性状纬度渐变的影响.“,”Aims Field and common garden comparisons are commonly performed to test the rapid evolution of increased vigor in introduced plant populations.Latitudinal clines in phenotypic traits can obscure such evolutionary inferences,particularly when native or introduced populations are distributed across large geographic ranges.We tested whether the latitudinal clines influence comparisons between introduced and native populations of Senecio vulgaris.Methods Senecio vulgaris is native to Europe but has been introduced in northeastern and southwestern China.To evaluate the performance in terms of growth and reproduction between native European populations and introduced Chinese populations,we compared plant height,number of branches and number of capitula in field populations in native and introduced ranges and in a common garden in Switzerland.Important Findings The introduced Chinese populations performed better than the native European populations in the field in terms of plant height and number of capitula,which was consistent with the prediction of the evolution of the increased competitive ability (EICA) hypothesis.The Chinese populations produced more capitula than the European populations when the latitudinal cline was considered in the common garden comparison.When we compared the traits of the northeastern Chinese,southwestern Chinese and European populations in both the field and common garden,the northeastern Chinese populations,at latitudes similar to those of the European populations,exhibited greater plant size and more capitula than the European populations in both the field and common garden.However,the southwestern Chinese populations,at latitudes much lower than those of the European populations,did not perform better than the native populations in terms of reproduction.In conclusion,our results suggest that latitudinal clines in phenotypic traits should be considered in field and common garden comparisons when introduced populations are geographically structured.