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.

一个物种种群的结构与演化历史，是指导生态修复中现有本土植物材料应用、以及规划未来修复需求所需新型本土植物材料研发的关键依据。美国西部的蓝丛冰草（*Pseudoroegneria spicata*，禾本科Poaceae）是草原与灌丛植物群落的重要组成组分，因其耐旱性与对外来杂草的竞争优势，常被用于生态修复工程。本研究利用高通量测序（next-generation sequencing, NGS）数据，解析了美国山间西地区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冰盛期（Last Glacial Maximum）以来发生了遗传分化。相邻种群间的历史基因流强度存在差异，迁移速率范围覆盖每代多个迁移个体至每迁移个体历经多代。针对当前可用于生态修复的商用种质资源，其遗传特征仍能代表其最初采集的野生原生境，且保持了较高水平的杂合度与核苷酸多样性。但此类商用种质资源仅占山间西地区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间迁移速率较低且分化时间较长，即便商用植物材料的适宜生境与修复位点环境相似，在部分地理区域使用该类商用种质资源仍可能引发不理想的修复结果。因此，种群结构与演化历史可用于指导确定需要补充本土植物材料的地理区域，从而使生态修复工作助力物种种群与群落的恢复力提升，并改善修复成效。