Department of Biological Sciences, University of Illinois Chicago, M/C 066, Chicago IL 60607, USA.
Ann Bot. 2009 Dec;104(7):1413-9. doi: 10.1093/aob/mcp239. Epub 2009 Oct 1.
Many plants reproduce both clonally and sexually, and the balance between the two modes of reproduction will vary among populations. Clonal reproduction was characterized in three populations of the wild strawberry, Fragaria virginiana, to determine the extent that reproductive mode varied locally between sites. The study sites were fragmented woodlands in Cook County, Illinois, USA.
A total of 95 strawberry ramets were sampled from the three sites via transects. Ramets were mapped and genotyped at five variable microsatellite loci. The variability at these five loci was sufficient to assign plants to clones with high confidence, and the spatial pattern of genets was mapped at each site.
A total of 27 distinct multilocus genotypes were identified. Of these, 18 genotypes were detected only once, with the remaining nine detected in multiple ramets. The largest clone was identified in 16 ramets. No genets were shared between sites, and each site exhibited markedly different clonal and sexual recruitment patterns, ranging from two non-overlapping and widespread genets to 19 distinct genets. Only one flowering genet was female; the remainder were hermaphrodites.
Local population history or fine-scale ecological differences can result in dramatically different reproductive patterns at small spatial scales. This finding may be fairly widespread among clonal plant species, and studies that aim to characterize reproductive modes in species capable of asexual reproduction need to evaluate reproductive modes in multiple populations and sites.
许多植物既进行无性繁殖又进行有性繁殖，两种繁殖方式的平衡在种群之间会有所不同。本研究以三个野生草莓种群（弗吉尼亚草莓， Fragaria virginiana）为对象，对其克隆繁殖特征进行了研究，以确定局部繁殖方式在各地点之间的差异程度。研究地点位于美国伊利诺伊州库克县的 fragmented woodlands。
通过样线在三个地点共采集了 95 株草莓匐匍茎。对匐匍茎进行了绘图和 5 个可变微卫星位点的基因型分析。这 5 个位点的变异性足以高度置信地将植物分配到克隆体中，并在每个地点绘制了遗传体的空间模式。
共鉴定出 27 个不同的多基因座基因型。其中，18 个基因型仅出现过一次，其余 9 个基因型在多个匐匍茎中出现。最大的克隆体在 16 个匐匍茎中被发现。没有遗传体在各地点之间共享，每个地点的克隆和有性繁殖模式都明显不同，范围从两个不重叠且广泛分布的遗传体到 19 个不同的遗传体。只有一个有花遗传体是雌性，其余的都是雌雄同体。
局部种群历史或小尺度生态差异可导致小空间尺度上的繁殖模式显著不同。这种发现可能在许多克隆植物物种中相当普遍，旨在对具有无性繁殖能力的物种的繁殖模式进行特征描述的研究需要在多个种群和地点评估繁殖模式。
