2025-04-282025-04-282024-12-06Valle García, J.C.d., Arista Palmero, M., Benítez Benítez, C., Ortiz Ballesteros, P.L., Jiménez López, F.J., Terrab Benjelloun, A. y Balao Robles, F.J. (2024). Genomic-Guided Conservation Actions to Restore the Most Endangered Conifer in the Mediterranean Basin.. Molecular Ecology, 1-12. https://doi.org/10.1111/mec.17605.0962-10831365-294Xhttps://hdl.handle.net/11441/172204Species with extremely small population sizes are critically endangered because of reduced genetic diversity, increased inbreed-ing and hybridisation threats. Genomic tools significantly advance conservation by revealing genetic insights into endangeredspecies, notably in monitoring frameworks. Sicilian fir (Abies nebrodensis) is the most endangered conifer in Europe with only30 adult trees in an 84-ha area. Using 20,824 SNPs from RAD-seq, employing genome assembly and a custom 120 SNP-array,we evaluated genetic diversity, mating patterns, and effective population size in adult trees, 118 natural seedlings, and 2064nursery seedlings from past conservation actions. We assessed introgression from neighbouring non-native fir plantations (~6%)and established an intra-population assisted gene flow (AGF) program selecting the most genetically dissimilar individuals andinvestigating the outcome through simulations. Genomic analysis unveiled significant genetic diversity among adult Sicilianfirs, comparable to non-endangered Mediterranean firs with larger populations. However, the genetic diversity of the forthcom-ing generation declined due to high self-fertilisation, leading to marked inbreeding (F IS = 0.38) and an alarmingly low effectivepopulation size (Ne = 6). Nursery seedling monitoring revealed similar selfing rates and introgression (~2%) from non-native firs.Although intra-population AGF could help to mitigate genetic loss, it may not alleviate the species vulnerability to imminentenvironmental challenges, perpetuating the risk of an extinction vortex. Hence, investigating the impact of Sicilian fir populationdecline and selfing on inbreeding depression, along with exploring the potential of hybrids for genetic load alleviation and futureadaptation, is crucial for effective conservation strategiesapplication/pdf12 p.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Abies nebrodensis | Conservation genomics | Hybridisation | Inbreeding | Reforestation | Small populations | Within-population assisted gene flowinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.1111/mec.17605