Data from: Capturing genetic variation in crop wild relatives: an evolutionary approach

Crop wild relatives (CWRs) offer novel genetic resources for crop improvement. To assist in the urgent need to collect and conserve CWR germplasm, we advance here the concept of an ‘evolutionary’ approach. Central to this approach is the predictive use of spatial proxies of evolutionary processes (natural selection, gene flow, and genetic drift) to locate and capture genetic variation. As a means to help validate this concept, we screened wild-collected genotypes of woodland strawberry (Fragaria vesca) in a common garden. A quantitative genetics approach was then used to test the ability of two such proxies – mesoclimatic variation (a proxy of natural selection) and landscape isolation and geographic distance between populations (proxies of gene flow potential) – to predict spatial genetic variation in three quantitative traits (plant size, early season flower number, and flower frost tolerance). Our results indicated a significant but variable effect of mesoclimatic conditions in structuring genetic variation in the wild, in addition to other undetermined regional scale processes. As a proxy of gene flow potential, landscape isolation was also a likely determinant of observed patterns – as opposed to and regardless of geographic distance between populations. We conclude that harnessing proxies of adaptive and non-adaptive evolutionary processes could provide a robust and valuable means to identify genetic variation in CWRs. We thus advocate wider use of this approach amongst researchers, breeders, and practitioners, to expedite the capture and in situ conservation of genetic resources provided by crop wild relatives.

作物野生近缘种（Crop wild relatives, CWRs）可为作物遗传改良提供新颖的遗传资源。为应对当前收集与保育CWR种质资源的迫切需求，本文提出了一种「进化研究范式」。该范式的核心在于，通过预测性地利用进化过程（自然选择、基因流与遗传漂变）的空间代理指标，定位并捕获遗传变异。为验证这一概念，研究团队在同质种植园中对野生采集的森林草莓（Fragaria vesca）基因型进行了筛选。随后采用数量遗传学方法，以两类代理指标——中气候变异（自然选择的代理指标）以及种群间的景观隔离度与地理距离（基因流潜力的代理指标）——检验其对3个数量性状（植株大小、早期开花数、花霜冻抗性）空间遗传变异的预测能力。研究结果表明，除其他未明确的区域尺度过程外，中气候条件对野生群体的遗传变异格局构建具有显著但存在差异的影响。作为基因流潜力的代理指标，景观隔离度同样是观测到的遗传变异格局的潜在决定因素——其作用与种群间地理距离无关，且地理距离并未表现出类似效应。本研究结论认为，利用适应性与非适应性进化过程的代理指标，可为识别CWRs的遗传变异提供稳健且极具价值的途径。因此，我们倡导研究人员、育种者与实践者广泛采用该方法，以加快对作物野生近缘种所提供的遗传资源的收集与原位保育。