生物多样性 ›› 2020, Vol. 28 ›› Issue (6): 651-657.DOI: 10.17520/biods.2020044

• 研究报告:植物多样性 •    下一篇

喜旱莲子草对同基因型邻体根系的表型可塑性: 入侵地和原产地的比较

于良瑞1,2,朱政财4,潘晓云1,2,3,*()   

  1. 1 复旦大学生物多样性与生态工程教育部重点实验室, 上海 200438
    2 西藏大学-复旦大学生物多样性与全球变化联合实验室, 拉萨 850000
    3 西藏大学生命科学系与生物多样性研究所, 拉萨 850000
    4 广州市增城区林业和园林科学研究所, 广州 511300
  • 收稿日期:2020-02-16 接受日期:2020-04-03 出版日期:2020-06-20 发布日期:2020-08-19
  • 通讯作者: 潘晓云
  • 基金资助:
    国家自然科学基金(41771053)

Phenotypic plasticity of Alternanthera philoxeroides in response to root neighbors of kin: Introduced vs. native genotypes

Liangrui Yu1,2,Zhengcai Zhu4,Xiaoyun Pan1,2,3,*()   

  1. 1 Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Fudan University, Shanghai 200438
    2 Tibet University-Fudan University Joint Laboratory for Biodiversity and Global Change, Lhasa 850000
    3 Institute of Biodiversity, Department of Biology, Tibet University, Lhasa 850000
    4 Guangzhou Zengcheng Institute of Forestry and Landscape Architecture, Guangzhou 511300
  • Received:2020-02-16 Accepted:2020-04-03 Online:2020-06-20 Published:2020-08-19
  • Contact: Xiaoyun Pan

摘要:

植物对邻体根系的表型可塑性是指与无邻体对照相比, 即使个体平均可获取土壤资源相同, 在有邻体根系存在时植物也会改变根系生物量分配, 并影响其他功能性状和适合度。表型可塑性进化假说(evolution of plasticity hypothesis)认为外来植物在入侵地进化出了更强的表型可塑性。对该假说的验证多集中于外来植物对光照、水分、养分以及天敌等的可塑性进化, 但对邻体根系的可塑性在入侵植物中是否发生进化尚未见报道。我们采用同质园实验比较了喜旱莲子草(Alternanthera philoxeroides)入侵地(美国)和原产地(阿根廷)各5个基因型的适合度与功能性状对同基因型邻体根系的可塑性。结果表明: 喜旱莲子草的根冠比(P = 0.088)和比叶面积(P = 0.007)对同基因型邻体根系的可塑性在入侵地和原产地基因型间存在差异: 入侵地基因型在有邻体根系时根冠比和比叶面积增加, 而原产地基因型则相反。但是, 总生物量、贮藏根生物量、比茎长和分枝强度对邻体根系的可塑性在入侵地和原产地间没有显著差异。此外, 与分隔邻体根系相比, 同基因型邻体根系存在时总生物量(+9.9%)和贮藏根生物量(+13.9%)显著增加, 比茎长(-9.5%)显著降低。最后, 与原产地基因型相比, 总体上入侵地基因型的总生物量(+62.0%)和贮藏根生物量(+58.9%)增加, 比茎长(-28.5%)和分枝强度(-42.8%)降低。这些结果表明喜旱莲子草入侵地基因型与资源利用相关功能性状(如根冠比和比叶面积)对邻体根系的可塑性方向与原产地基因型相反; 但适合度和株型相关性状(如比茎长和分枝强度)对同基因型邻体根系的可塑性与原产地没有差异。

关键词: 邻体效应, 同基因型间互作, 表型可塑性, 植物入侵, 进化

Abstract:

Plant root neighbors can induce plastic responses, thereby altering root biomass allocation and other functional traits even while available resources remain constant. The evolution of plasticity hypothesis demonstrates that populations in the introduced range of an invasive species have evolved greater plasticity than populations in the native range. Most studies focus on plastic responses of alien plants to light, water, nutrition and nature enemies. However, plastic responses to root neighbors in alien plants has not been studied. We conducted a common garden experiment using five introduced (the United States of America, USA) and five native (Argentina) genotypes of Alternanthera philoxeroides (alligator weed) to compare fitness and functional traits responses to root neighbors of the same genotype plants (kin). We found that introduced genotypes had an increased root to shoot ratio (RSR) and specific leaf area (SLA) when root neighbors were present while the native genotypes showed the opposite responses. However, introduced and native genotypes showed no difference in total biomass, storage root biomass, specific stem length (SSL) and branching intensity (BI). In addition, when root neighbors were present, A. philoxeroides increased in total biomass (+9.9%) and storage root biomass (+13.9%) and decreased in SSL (-9.5%) than when grown without root neighbors. Introduced genotypes showed an increase in total biomass (+62.0%), storage root biomass (+58.9%), and reduction of SSL (-28.5%) and BI (-42.8%) than native genotypes. Our results suggest that functional trait plasticity responses related to resource utilization (i.e. RSR and SLA) showed opposite patterns between introduced and native genotypes, but fitness and functional trait plasticity responses related to plant type (i.e. SSL and BI) showed no difference among introduced and native genotypes.

Key words: neighbor effect, intra-genotypic interaction, phenotypic plasticity, plant invasion, evolution