Retrospective genetic monitoring of the threatened Yellow marsh saxifrage ( Saxifraga hirculus) reveals genetic erosion but provides valuable insights for conservation strategies

• Published in: Diversity and Distributions
• Main Authors: Beatty, Gemma E., Reid, Neil, Provan, Jim
• Other Authors: Lowe, Andrew
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2013
• Subjects: Yellow Marsh; Marsh Saxifrage; Saxifraga hirculus
• Online Access: http://dx.doi.org/10.1111/ddi.12158; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fddi.12158; https://onlinelibrary.wiley.com/doi/pdf/10.1111/ddi.12158

Abstract Aim Retrospective genetic monitoring, comparing genetic diversity of extant populations with historical samples, can provide valuable and often unique insights into evolutionary processes informing conservation strategies. The Yellow marsh saxifrage ( S axifraga hirculus ) is listed as ‘critically endangered’ in Ireland with only two extant populations. We quantified genetic changes over time and identified genotypes in extant populations that could be used as founders for reintroductions to sites where the species is extinct. Location Ireland. Methods Samples were obtained from both locations where the species is currently found, including the most threatened site at the G arron P lateau, C o. A ntrim, which held only 13 individuals during 2011. Herbarium samples covering the period from 1886 to 1957 were obtained including plants from the same area as the most threatened population, as well as three extinct populations. In total, 422 individuals (319 present‐day and 103 historical) were genotyped at six microsatellite loci. Species distribution modelling was used to identify areas of potentially suitable habitat for reintroductions. Results Level of phenotypic diversity within the most threatened population was significantly lower in the present‐day compared with historical samples but levels of observed heterozygosity and number of alleles, whilst reduced, did not differ significantly. However, B ayesian clustering analysis suggested gradual lineage replacement over time. All three measures of genetic diversity were generally lower at the most threatened population compared with the more substantial extant populations in C o. Mayo. Species distribution modelling suggested that habitat at one site where the species is extinct may be suitable for reintroduction. Main conclusions The dominant genetic lineage in the most threatened population is rare elsewhere; thus, care needs to be taken when formulating any potential reintroduction programme. Our findings highlight both the need for genetic monitoring ...