Data from: Anthropogenic and natural drivers of gene flow in a temperate wild fruit tree: a basis for conservation and breeding programs in apples

Gene flow is an essential component of population adaptation and species evolution. Understanding of the natural and anthropogenic factors affecting gene flow is also critical for the development of appropriate management, breeding and conservation programs. Here, we explored the natural and anthropogenic factors impacting crop-to-wild and within wild gene flow in apples in Europe using an unprecedented dense sampling of 1,889 wild apple (Malus sylvestris) from European forests and 339 apple cultivars (Malus domestica). We made use of genetic, environmental and ecological data (microsatellite markers, apple production across landscapes and records of apple flower visitors respectively). We provide the first evidence that both human activities, through apple production, and human disturbance, through modifications of apple flower visitor diversity, have had a significant impact on crop-to-wild interspecific introgression rates. Our analysis also revealed the impact of previous natural climate change on historical gene flow in the non-introgressed wild apple M. sylvestris, by identifying five distinct genetic groups in Europe and a north-south gradient of genetic diversity. These findings identify human activities and climate as key drivers of gene flow in a wild temperate fruit tree, and provide a practical basis for conservation, agroforestry and breeding programs for apples in Europe.

基因流（gene flow）是种群适应与物种演化的核心组成部分。明晰影响基因流的自然与人为因素，同样对制定合理的管理、育种与保护方案至关重要。本研究针对欧洲苹果的作物-野生种间以及野生种群内部的基因流影响因素展开探究：我们从欧洲森林中采集了1889份欧洲野苹果（Malus sylvestris）样本与339份栽培苹果（Malus domestica）样本，采样密度空前。本研究分别利用了遗传、环境与生态学三类数据：微卫星标记（microsatellite markers）、区域苹果生产数据以及苹果访花昆虫记录。本研究首次证实：通过苹果生产产生的人类活动，以及通过改变苹果访花昆虫多样性引发的人为干扰，均对作物-野生种间的种间渐渗（interspecific introgression）速率产生了显著影响。分析同时揭示了既往自然气候变化对未发生渐渗的野生苹果M. sylvestris历史基因流的影响：我们在欧洲境内鉴定出5个独立的遗传类群，且遗传多样性呈现南北梯度分布。本研究结果明确了人类活动与气候是温带野生果树基因流的关键驱动因子，并为欧洲苹果的保护、农林业复合经营与育种项目提供了实用依据。