Founder events and subsequent genetic bottlenecks underlie karyotype evolution in the Ibero-North African endemic Carex helodes.

Autor:	Escudero M; Department of Plant Biology and Ecology, University of Seville, 41012 Seville, Spain.; Department of Integrative Ecology, Doñana Biological Station, CSIC, 41092 Seville, Spain., Arroyo JM; Department of Integrative Ecology, Doñana Biological Station, CSIC, 41092 Seville, Spain., Sánchez-Ramírez S; Department of Ecology and Evolutionary Biology, University of Toronto, M5S 3B2 Toronto, Ontario, Canada., Jordano P; Department of Plant Biology and Ecology, University of Seville, 41012 Seville, Spain.; Department of Integrative Ecology, Doñana Biological Station, CSIC, 41092 Seville, Spain.
Jazyk:	angličtina
Zdroj:	Annals of botany [Ann Bot] 2024 May 10; Vol. 133 (5-6), pp. 871-882.
DOI:	10.1093/aob/mcad087
Abstrakt:	Background and Aims: Despite chromosomal evolution being one of the major drivers of diversification in plants, we do not yet have a clear view of how new chromosome rearrangements become fixed within populations, which is a crucial step forward for understanding chromosomal speciation. Methods: In this study, we test the role of genetic drift in the establishment of new chromosomal variants in the context of hybrid dysfunction models of chromosomal speciation. We genotyped 178 individuals from seven populations (plus 25 seeds from one population) across the geographical range of Carex helodes (Cyperaceae). We also characterized karyotype geographical patterns of the species across its distribution range. For one of the populations, we performed a detailed study of the fine-scale, local spatial distribution of its individuals and their genotypes and karyotypes. Key Results: Synergistically, phylogeographical and karyotypic evidence revealed two main genetic groups: southwestern Iberian Peninsula vs. northwestern African populations; and within Europe our results suggest a west-to-east expansion with signals of genetic bottlenecks. Additionally, we inferred a pattern of descending dysploidy, plausibly as a result of a west-to-east process of post-glacial colonization in Europe. Conclusions: Our results give experimental support to the role of geographical isolation, drift and inbreeding in the establishment of new karyotypes, which is key in the speciation models of hybrid dysfunction. (© The Author(s) 2023. Published by Oxford University Press on behalf of the Annals of Botany Company.)
Databáze:	MEDLINE
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