Data from: Regional genetic structure and environmental variables influence our conservation approach for feather heads (Ptilotus macrocephalus)

Continued alterations to the Australian environment compromise the long-term viability of many plant species. We investigate the population genetics of Ptilotus macrocephalus a perennial herb that occurs in two nationally endangered communities on the Victorian Volcanic Plain Bioregion (VVP), Australia, to answer key questions regarding regional differentiation and to guide conservation strategies. We evaluate genetic structure and diversity within and among 17 P. macrocephalus populations from 3 regions of southeastern Australia using 17 microsatellite markers developed de novo. Genetic structure was present in P. macrocephalus between the three regions but not at the population level. Environmental factors, namely temperature and precipitation, significantly explained differentiation between the North region and the other two regions indicating isolation by environment. Within regions, genetic structure currently shows a high level of gene flow and genetic variation. Our results suggest that within-region gene flow does not reflect current habitat fragmentation in southeastern Australia whereas temperature and precipitation are likely to be responsible for the differentiation detected among regions. Climate change may severely impact P. macrocephalus on the VVP and test its evolutionary resilience. We suggest taking a proactive conservation approach to improve long-term viability by sourcing material for restoration to assist gene flow to the VVP region to promote an increased adaptive capacity.

澳大利亚生态环境的持续改变，正危及诸多植物物种的长期存续能力。本研究以澳大利亚维多利亚火山平原生物区（Victorian Volcanic Plain Bioregion，简称VVP）内两处国家级濒危群落中的多年生草本植物头花银锤草（Ptilotus macrocephalus）为研究对象，开展种群遗传学研究，旨在解答区域分化相关的核心科学问题，并为针对性保护策略的制定提供理论指导。本研究利用17个从头开发的微卫星（microsatellite）标记，对澳大利亚东南部3个区域内的17个头花银锤草种群的种群内及种群间遗传结构与遗传多样性进行了系统评估。结果显示，头花银锤草的遗传结构在三个区域间存在显著分化，但在种群水平上未呈现明显的遗传结构。环境因子（即温度与降水量）可显著解释北部区域与另外两个区域间的遗传分化，表明存在环境隔离效应。在区域内部，当前的遗传结构表现出高水平的基因流与遗传变异。研究结果表明，区域内的基因流并未与澳大利亚东南部当前的生境破碎化状况相匹配，而温度与降水量或是区域间检测到的遗传分化的主要驱动因素。气候变化可能会严重威胁维多利亚火山平原生物区内头花银锤草的生存，并对其进化适应性构成严峻考验。我们建议采取积极主动的保护策略：通过为生态修复工程采集适配种质资源，辅助基因流向维多利亚火山平原生物区流动，以提升该区域物种的自适应能力，从而改善其长期存续能力。