Clone configuration and spatial genetic structure of two Halophila ovalis populations with contrasting internode lengths

Fine-scale spatial genetic structure (SGS) is predominantly determined by gene flow. While sexually reproducing plants can disperse their genes through pollen and seed grains, clonal plants can additionally disperse genes through clonal growth. Plants’ clonal reproduction strategy, however, often varies within and between species. Still, the effect of differential clonal reproduction strategy on fine-scale SGS remains somewhat unclear. Halophila ovalis is a fast-growing clonal seagrass, whose internode length (which defines a species’ clonal reproduction strategy) varies among populations. Using eight polymorphic microsatellites, here we compare the genetic diversity, clonal structure and fine-scale SGS of two H. ovalis populations with contrasting internode lengths (Yingluo versus Xialongwei populations). We found moderate to high genotypic and allelic richness and heterozygosities in both populations. Compared to Xialongwei population, genetic and genotypic diversity was significantly...

精细尺度空间遗传结构（Fine-scale spatial genetic structure, SGS）主要由基因流决定。有性繁殖植物可通过花粉与种子传播自身基因，而克隆繁殖植物还可额外通过克隆生长实现基因扩散。不过，植物的克隆繁殖策略往往在种群内部及物种间存在差异。但差异化克隆繁殖策略对精细尺度空间遗传结构的影响目前仍不甚明确。卵叶喜盐草（Halophila ovalis）是一种生长迅速的克隆海草，其节间长度（该指标决定物种的克隆繁殖策略）在不同种群间存在变异。本研究采用8个多态性微卫星（microsatellites）标记，对比了两个节间长度特征迥异的卵叶喜盐草种群——英罗（Yingluo）种群与下龙尾（Xialongwei）种群的遗传多样性、克隆结构及精细尺度空间遗传结构。研究结果显示，两个种群均具备中等至高水平的基因型丰富度、等位基因丰富度与杂合度。与下龙尾种群相比，英罗种群的遗传与基因型多样性显著……