Genomic, karyological, and morphological changes of South American garlics (Ipheion) provide insights into mechanisms of speciation in the Pampean region

Speciation proceeds through mechanisms that promote reproductive isolation and shape the extent of genetic variation in natural populations, and thus, its study is essential to understand the evolutionary processes leading to increased biodiversity. Chromosomal rearrangements are known to facilitate reproductive isolation by hybrid sterility and favor speciation events. The genus Ipheion (Amaryllidaceae, Allioideae) is unique as its species exhibits a remarkable karyological variability but lack population-level genetic data. To unveil diversification processes acting upon the formation of new lineages within Ipheion in the Pampas of South America, we combined morphology and karyology approaches with genotyping-by-sequencing. Our phylogenomic and population genomics results supported the taxonomic division of Ipheion into three morphological and genetically well-differentiated groups. The origin of I. uniflorum was traced back to its current southern distribution area in the southern Pa...