Habitat fragmentation influences genetic diversity and differentiation: Fine-scale population structure of Cercis canadensis (eastern redbud)

Forest fragmentation may negatively affect plants through reduced genetic diversity and increased population structure due to habitat isolation, decreased population size, and disturbance of pollen-seed dispersal mechanisms. However, in the case of tree species, effective pollen-seed dispersal, mating system, and ecological dynamics may help the species overcome the negative effect of forest fragmentation. A fine-scale population genetics study can shed light on the postfragmentation genetic diversity and structure of a species. Here, we present the genetic diversity and population structure of Cercis canadensis L. (eastern redbud) wild populations on a fine scale within fragmented areas entered around the borders of Georgia–Tennessee, USA. We hypothesized high genetic diversity among the collections of C. canadensis distributed across smaller geographical ranges. Fifteen microsatellite loci were used to genotype 172 individuals from 18 unmanaged and naturally occurring collection sites...

森林破碎化可通过生境隔离、种群规模缩减以及花粉-种子传播机制受干扰等途径，降低植物遗传多样性并加剧种群遗传结构分化，从而对植物产生负面影响。然而对于树木类群而言，高效的花粉-种子传播能力、交配系统以及生态动态过程或可帮助其抵消森林破碎化带来的负面影响。精细尺度种群遗传学研究可阐明物种在经历森林破碎化后的遗传多样性与种群结构特征。本研究针对美国佐治亚州与田纳西州边境周边破碎化生境中的野生加拿大紫荆（Cercis canadensis L.，Eastern Redbud）种群开展精细尺度分析，对其遗传多样性与种群结构进行了报道。我们提出研究假设：尽管采样得到的加拿大紫荆种群分布于较小的地理范围之内，但其仍具备较高的遗传多样性。本研究采用15个微卫星位点（microsatellite loci），对来自18个未受人为干扰的自然采样点的172个个体进行了基因分型……