Data from: Cultivation shapes genetic novelty in a globally important invader

Acacia saligna is a species complex that has become invasive in a number of countries worldwide where it has caused substantial environmental and economic impacts. Understanding genetic and other factors contributing to its success may allow managers to limit future invasions of closely related species. We used three molecular markers to compare the introduced range (South Africa) to the native range (Western Australia). Nuclear markers showed that invasive populations are divergent from native populations and most closely related to a cultivated population in Western Australia. We also found incongruence between nuclear and chloroplast data that, together with the long history of cultivation of the species, suggest that introgressive hybridization (coupled with chloroplast capture) may have occurred within A. saligna. While we could not definitively prove introgression, the genetic distance between cultivated and native A. saligna populations was comparable to known interspecific divergences among other Acacia species. Therefore, cultivation, multiple large-scale introductions and possibly introgressive hybridization have rapidly given rise to the divergent genetic entity present in South Africa. This may explain the known global variation in invasiveness and inaccuracy of native bioclimatic models in predicting potential distributions.银叶金合欢（Acacia saligna）是一个物种复合群（species complex），现已在全球多个国家沦为入侵物种，造成了严重的生态与经济损失。明确其成功入侵的遗传与其他相关驱动因素，可为管理者限制近缘物种的未来入侵态势提供理论依据。本研究采用三类分子标记（molecular markers），将该物种的入侵分布区（introduced range，南非）与原生分布区（native range，西澳大利亚）进行比对分析。核分子标记（nuclear markers）分析结果显示，入侵种群与原生种群存在显著遗传分化，且与西澳大利亚的栽培种群亲缘关系最为密切。研究同时发现核基因组与叶绿体基因组数据（chloroplast data）存在不一致性，结合该物种悠久的栽培历史，提示银叶金合欢内可能发生了渐渗杂交（introgressive hybridization）并伴随叶绿体捕获（chloroplast capture）事件。尽管本研究无法确凿证实渐渗杂交的发生，但栽培种群与原生银叶金合欢种群之间的遗传距离，与其他金合欢属（Acacia）物种间已知的种间分化水平相当。综上，栽培活动、多次大规模引种，以及可能存在的渐渗杂交，共同快速塑造了南非境内出现的分化遗传类群。这一结果或可解释全球范围内已观测到的入侵性差异，以及基于原生分布区的生物气候模型（native bioclimatic models）在预测物种潜在分布时所存在的预测精度不足问题。