Hybridization and Polyploidy Shaped the Evolutionary History of a Complex of Cryptic Species in European Woodrushes ( Luzula sect. Luzula )

作者：Valentin Heimer, Pau Carnicero, Carolina Carrizo García, Andreas Hilpold, Jasna Dolenc Koce, Jocelyne Leal, Mingai Li, Claudio Varotto, Peter Schönswetter, Božo Frajman · 发表于：Systematic Biology · 年份：2025 · DOI：10.1093/sysbio/syaf065 · 被引用次数：1 · 研究领域：Genetic diversity and population structure、Plant Taxonomy and Phylogenetics、Chromosomal and Genetic Variations

Polyploidization has played a central role in the evolutionary history of most plant lineages, yet it poses significant challenges for phylogenetic inference, particularly in allopolyploid complexes with reticulate species relationships. Luzula sect. Luzula (Juncaceae) is a taxonomically intricate group characterized by widespread polyploidy, agmatoploidy, and high morphological uniformity. Focusing on the Eastern Alps, a key center of its diversity, we collected 1002 samples of nine species and applied an integrative framework combining ddRADseq, plastid sequencing, relative genome size estimation, and chromosome counting to disentangle its evolutionary history. We extended previously inferred phylogenetic relationships and assessed gene flow among diploids, establishing a baseline for investigating the origin of polyploids. By analyzing patterns of genotype frequencies and genetic affinities to diploids, we inferred the most likely parental species of polyploids and identified key hybridization events shaping the current taxonomic and karyotypic diversity within this group. Our results reveal weak genetic differentiation among some diploid lineages, likely reflecting gene flow and incomplete lineage sorting. We propose a common allopolyploid origin of two tetraploids, which subsequently gave rise to a third tetraploid and a hexaploid species through interploidy hybridization. Although the parental species of some polyploids remain obscure, our genomic data highlight polyplo...