Variation in the intensity of inbreeding depression among successive life‐cycle stages and generations in gynodioecious Silene vulgaris (Caryophyllaceae)
Variation in the intensity of inbreeding depression among successive life‐cycle stages and generations in gynodioecious Silene vulgaris (Caryophyllaceae)
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雌雄异株的 Silene vulgaris（石竹科）连续生命周期阶段和世代之间近交衰退强度的变化
DOI：
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发表时间：
2006
影响因子：
2.1
通讯作者：
J. Goudet
中科院分区：
文献类型：
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作者：
M. Glaettli;J. Goudet
近交衰退是解释雌株异株植物种群中雌株维持的假说之一。然而，在自交和异交后代中的适合度分量的测量取决于生命周期阶段和近交的历史。比较数据表明，强烈的近交衰退更有可能发生在生命周期的后期阶段。我们使用了来自瑞士阿尔卑斯山不同山谷的三个种群的两性个体，研究了两代自花受精和异花受精对温室实验中生命周期连续阶段中健身成分的影响。我们在大多数生命周期阶段检测到显著的近交衰退，包括：每个果实的存活和败育种子数量，发芽概率，地上生物量，开花概率，每株植物的花数，花大小和花粉活力。总体而言，近交衰退的强度在生活史的连续阶段中增加，并且第一代的累积近交衰退（δ = 0.5）显著强于第二代（δ = 0.35）。 我们在实验中没有发现协同上位性的证据。我们发现在生活史的后期阶段更强烈的近亲繁殖衰退可能有助于解释雌性在雌性雌雄异株种群中的维持。因为基因负荷的清除不太可能发生。
Inbreeding depression is one of the hypotheses explaining the maintenance of females within gynodioecious plant populations. However, the measurement of fitness components in selfed and outcrossed progeny depends on life‐cycle stage and the history of inbreeding. Comparative data indicate that strong inbreeding depression is more likely to occur at later life‐cycle stages. We used hermaphrodite individuals of Silene vulgaris originating from three populations located in different valleys in the Swiss Alps to investigate the effect of two generations of self‐ and cross‐fertilization on fitness components among successive stages of the life cycle in a glasshouse experiment. We detected significant inbreeding depression for most life‐cycle stages including: the number of viable and aborted seeds per fruit, probability of germination, above ground biomass, probability of flowering, number of flowers per plant, flower size and pollen viability. Overall, the intensity of inbreeding depression increased among successive stages of the life cycle and cumulative inbreeding depression was significantly stronger in the first generation (δ ≈ 0.5) compared with the second generation (δ ≈ 0.35). We found no evidence for synergistic epistasis in our experiment. Our finding of more intense inbreeding depression during later stages of the life cycle may help to explain the maintenance of females in gynodioecious populations of S. vulgaris because purging of genetic load is less likely to occur.