Unveiling the Genetic Diversity and Population Structure of the Endangered Fern Angiopteris fokiensis Through Genome Survey and Genomic SSR Markers

<i>Angiopteris fokiensis</i> is an endangered fern with ecological and medicinal value, yet genetic studies to support its conservation have been scarce. We performed a genome survey using high-throughput sequencing, developed genomic SSR markers from a draft assembly, and genotyped 96 individuals from 10 populations in Guangdong Province. The genome size was ~4.44 Gb (1.89% heterozygosity). From a 3.58 Gb contig assembly, 4,327,181 SSR loci were identified, with 15 highly polymorphic SSR markers being developed. Genotyping showed high within-population genetic diversity, low inter-population differentiation, and 98.55% of variation within populations. Bayesian structure, principal coordinates analysis, and neighbor-joining tree analyses consistently indicated admixed genetic clusters without clear geographical division. Additionally, the analysis revealed no significant correlation between genetic and geographic distances. Conservation should prioritize intra-population diversity via in situ/ex situ strategies. This study provides the first genomic SSR resources for <i>A. fokiensis</i> and underscores the importance of conserving within-population genetic diversity through integrated in situ and ex situ strategies.