Environmental and genetic effects on phenotypic differences between Elaeocarpus photiniifolia (Elaeocarpaceae) ecotypes in dry and mesic habitats on a Japanese oceanic island
Environmental and genetic effects on phenotypic differences between Elaeocarpus photiniifolia (Elaeocarpaceae) ecotypes in dry and mesic habitats on a Japanese oceanic island
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DOI：
10.1111/1442-1984.12397
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发表时间：
2022-12-23
影响因子：
1.4
通讯作者：
Yoshimaru，Hiroshi
中科院分区：
文献类型：
--
作者：
Sugai，Kyoko;Setsuko，Suzuki;Yoshimaru，Hiroshi
生态物种形成是表型和遗传分化的结果，这是由不同环境之间的分化选择和生殖隔离所驱动的。在博宁群岛特有植物elaeocarpus photiniifolia中，Chichijima岛群发生了干燥生境灌木生态型和mesic生境乔木生态型的遗传分化，两种生态型之间存在着基因的流动和迁移。为了阐明环境和遗传因素对不同生态型植物性状差异的影响，本研究对Chichijima岛两个地区干旱和湿润生境的土壤含水量、核微卫星基因型、株高和开花物候进行了研究。6 ~ 7月，两区土壤含水量均呈下降趋势，7月干燥生境土壤含水量低于湿润生境。遗传结构不仅表现出生态型间的遗传分化，还表现出生态型间的混合和生境间的迁移。在植物高度和开花物候方面，环境和遗传因素均有显著影响：在干旱生境中，灌木生态型的植物高度较低，开花时间较早，表明其在干旱条件下具有表型可塑性，且两种性状在生态型之间存在遗传变异。这些结果表明，不同环境下的表型可塑性导致了不同的开花物候，从而促进了生殖隔离和遗传分化，从而导致了与环境相关的适应性状的遗传变异。
Ecological speciation is a consequence of phenotypic and genetic differentiation, which is driven by divergent selection and reproductive isolation between different environments. InElaeocarpus photiniifolia, a plant species endemic to the Bonin Islands, genetic differentiation between a shrub ecotype in dry habitats and a tree ecotype in mesic habitats occurs in the Chichijima Island Group, while gene flow between the ecotypes and migration between the habitats are feasible. To clarify environmental and genetic effects on traits different between the ecotypes, we examined the soil moisture content, nuclear microsatellite genotypes, plant height, and flowering phenology in dry and mesic habitats in two areas on Chichijima Island. The soil moisture content decreased from June to July in both areas and tended to be lower in dry habitats than in mesic habitats in July. Genetic structure indicated not only genetic differentiation between the ecotypes but also admixture between them and migration between the habitats. Both environmental and genetic effects were detected in plant height and flowering phenology: lower height and earlier flowering of the shrub ecotype in the dry habitats, indicating phenotypic plasticity in response to drought, and genetic variation between ecotypes in both traits. These findings indicate that phenotypic plasticity in response to different environments results in different flowering phenology, which facilitates reproductive isolation and genetic differentiation, leading to genetic variation in adaptive traits associated with the environments.