Conservation Implications for the Iberian Narrow Endemic Androsace cantabrica (Primulaceae) Using Population Genomics With Target Capture Sequence Data

Abstract

Androsace cantabrica (Losa & P. Monts.) Kress is a narrow endemic alpine plant restricted to a few high-elevation localities in the Cantabrian Mountains of northern Spain. Although currently accepted as a distinct species, its close morphological and phylogenetic affinity to related taxa such as Androsace adfinis and Androsace halleri has led to historical uncertainty about its taxonomic status and evolutionary origin. Here, we use the universal Angiosperms353 target capture kit to generate nuclear and plastid data from A. cantabrica and closely related species in section Aretia. We employ phylogenomic analyses to clarify species boundaries and population genomic analyses to inform conservation management, as well as flow cytometry and sequence-based analysis using allelic frequencies to estimate its ploidy level. Phylogenetic analyses based on nuclear loci support A. cantabrica as a monophyletic clade, distinct from both A. adfinis and the A. halleri and Androsace laggeri clades, although topological incongruence with plastid data suggests historical hybridization. Flow cytometry and allelic frequency-based analysis indicate that A. cantabrica is tetraploid, differentiating it from A. halleri and A. laggeri, which are diploid. Population structure analyses reveal a shallow genetic split between eastern and western groups (F _ST = 0.04485), with higher genetic diversity observed in the east. We estimated the species' distribution, population sizes, and threats, and classified it as Vulnerable under IUCN criteria B1ab(ii,iii) + 2ab(ii,iii). We recommend targeted in situ management, ex situ seed conservation, and the establishment of a micro-reserve. This study illustrates the utility of Angiosperms353 data for resolving both taxonomic questions and conservation strategies in polyploid, range-restricted species.

Keywords: Angiosperms353; alpine ecosystem; conservation genetics; global warming; phylogenomics; population genomics; threatened species.