Data from: Population history provides foundational knowledge for utilizing and developing native plant restoration materials

A species’ population structure and history are critical pieces of information that can help guide the use of available native plant materials in restoration treatments and decide what new native plant materials should be developed to meet future restoration needs. In the western United States, Pseudoroegneria spicata (bluebunch wheatgrass; Poaceae) is an important component of grassland and shrubland plant communities and commonly used for restoration due to its drought resistance and competitiveness with exotic weeds. We used next-generation sequencing data to investigate the processes that shaped P. spicata’s geographic pattern of genetic variation across the Intermountain West. Pseudoroegneria spicata’s genetic diversity is partitioned into populations that likely differentiated since the Last Glacial Maximum. Adjacent populations display varying magnitudes of historical gene flow, with migration rates ranging from multiple migrants per generation to multiple generations per migrant. When considering the commercial germplasm sources available for restoration, genetic identities remain representative of the wildland localities from which germplasm sources were originally developed, and they maintain high levels of heterozygosity and nucleotide diversity. However, the commercial germplasm sources represent a small fraction of the overall genetic diversity of P. spicata in the Intermountain West. Given the low migration rates and long divergence times between some pairs of P. spicata populations, using commercial germplasm sources could facilitate undesirable restoration outcomes when used in certain geographic areas, even if the environment in which the commercial materials thrive is similar to that of the restoration site. As such, population structure and history can be used to provide guidance on what geographic areas may need additional native plant materials so that restoration efforts support species and community resilience and improve outcomes.

物种种群结构及其演化历史是指导生态修复的关键信息，既能为现有本土植物材料的修复应用提供决策依据，也可助力确定需研发的新型本土植物材料，以满足未来生态修复的需求。在美国西部，Pseudoroegneria spicata（蓝丛冰草；禾本科Poaceae）是草原与灌丛植物群落的核心组成部分，因其耐旱性与对外来杂草的竞争优势，常被应用于生态修复项目。本研究利用下一代测序（next-generation sequencing）数据，解析了美国西部山间地带（Intermountain West）蓝丛冰草遗传变异的地理分布格局及其形成过程。蓝丛冰草的遗传多样性被划分为多个种群，这些种群大概率自末次盛冰期（Last Glacial Maximum）以来便产生了遗传分化。相邻种群间的历史基因交流强度各异，迁移速率跨度广泛，从每代存在多个迁移个体，到单个迁移个体需历经多代才能完成传播。针对生态修复可用的商业种质资源而言，其遗传特征仍能代表最初选育该种质的原生野外种群，且保留了较高水平的杂合度与核苷酸多样性。但此类商业种质资源仅占美国西部山间地带蓝丛冰草整体遗传多样性的极小一部分。鉴于部分蓝丛冰草种群对间的基因流速率较低且分化时间较长，即便商业种质的适宜生长环境与修复位点的环境相似，在部分地理区域使用该类商业种质仍可能引发不理想的修复结果。据此，种群结构及其演化历史可用于指导确定哪些地理区域需要补充本土植物材料，从而使生态修复工作助力物种与群落的抗逆性提升，并优化修复效果。