Transgenerational plasticity provides ecological diversity for a seed heteromorphic species in response to environmental heterogeneity

Yang Fan, Yang Xuejun, Jerry M. Baskin, Carol C. Baskin, Cao Dechang, Huang Zhenying (通讯作者)


代间可塑性为异型植物应对环境提供了生态多样性
所有的生物都生长在异质的环境中。由于受到传播距离的限制,植物所生存的环境往往与其母代相近,因此,植物在世代间对环境资源的选择能力相对较弱(相对于动物)。最新的研究表明,植物母代能够将所经历的环境信息传递到下一代,对后代植株的表型产生影响,这种现象称为植物的代间效应(transgenerational effect)。代间效应被认为是联系母代环境与后代适应性的桥梁,在物种适应和进化方面起着重要的作用。但是,目前相关研究案例甚少。 本研究以在我国北方广布的一年生盐生植物角果碱蓬为研究对象,在毛乌素沙地自然气候环境条件下,通过连续两年的控制实验证实了角果碱蓬子代植株的繁殖分配、结实比例和种子萌发率等特征受到母代环境的影响。母代植株所经历的胁迫环境能够使子代植株的适合度增大,从而产生具有适应性的代间效应,提高了子代对区域环境的适应能力。因此,角果碱蓬的代间效应为种群提供了生态多样性,有利于种群在异质的环境中的维持和更新。


Abstract
An important but largely overlooked point in studies on annual plant species with heteromorphic diaspores is that the phenotypes can be affected by the maternal environmental conditions. We performed a 2-year pot experiment to evaluate transgenerational plasticity in response to heterogeneity of environmental conditions in the seed-dimorphic species Suaeda corniculata subsp. mongolica. We grew plants from dimorphic seeds (brown and black) of Suaeda corniculata in controlled favourable vs. stressful conditions (early vs. late germination timing or low vs. high soil salinity) for two generations, producing replicate individuals with all permutations of maternal (F0) and progeny (F1) conditions and seed morphs. We then measured the effects of two-generational conditions and seed morph histories on traits of plants (F1) and their offspring (F2). F1 progeny plants from late-germinating mothers allocated more biomass to seeds and produced fewer brown seeds than those from early-germinating mothers. F1 progeny plants that grew under the same salinity as their mothers had higher reproductive allocation than those that grew in the contrasting conditions. When progeny plants were grown in favourable conditions (early germination or low salinity), the stressful maternal conditions (late germination or high salinity) increased germination of black seeds. Moreover, the transgenerational effects of seed heteromorphism interacted with experimental conditions in determining performance of progeny generations. Thus, transgenerational plasticity provided ecological diversity in the regenerative strategy for a seed heteromorphic species, and it may contribute to population maintenance via benefiting offspring responses to temporal and spatial variations.
  • paper link