Natural epigenetic variation contributes to heritable flowering divergence in a widespread asexual dandelion lineage

Epigenetic variation has been proposed to contribute to the success of asexual plants, either as a contributor to phenotypic plasticity or by enabling transient adaptation via selection on transgenerationally stable, but reversible, epialleles. While recent studies in experimental plant populations have shown the potential for epigenetic mechanisms to contribute to adaptive phenotypes, it remains unknown whether heritable variation in ecologically relevant traits is at least partially epigenetically determined in natural populations. Here, we tested the hypothesis that DNA methylation variation contributes to heritable differences in flowering time within a single widespread apomictic clonal lineage of the common dandelion (Taraxacum officinale s. lat.). Apomictic clone members of the same apomictic lineage collected from different field sites showed heritable differences in flowering time, which was correlated with inherited differences in methylation-sensitive AFLP marker profiles. Di...表观遗传变异（epigenetic variation）已被提出可助力无性繁殖植物的适应性演化：既可作为表型可塑性（phenotypic plasticity）的驱动因素，亦可通过作用于跨代稳定但可逆的表观等位基因（epialleles），经选择介导实现瞬时适应性进化。尽管近期针对实验植物种群的研究已证实，表观遗传机制有望参与适应性表型的形成，但在自然种群中，生态相关性状的可遗传变异是否至少部分由表观遗传决定，目前仍不明确。本研究针对这一假说展开验证：即DNA甲基化变异（DNA methylation variation）可导致单一广布无融合生殖克隆谱系的普通蒲公英（Taraxacum officinale s. lat.）内，开花时间（flowering time）存在可遗传差异。研究发现，从不同野外生境采集的同一无融合生殖克隆谱系的克隆个体，其开花时间存在可遗传差异，且该差异与甲基化敏感AFLP（methylation-sensitive Amplified Fragment Length Polymorphism）标记谱的遗传差异呈显著相关。Di...