The sweet tabaiba or there and back again: phylogeographical history of the Macaronesian Euphorbia balsamifera

作者：Mario Rincón Barrado, Tamara Villaverde, Manolo F. Perez, Isabel Sanmartín, Ricarda Riina · 发表于：Annals of Botany · 年份：2024 · DOI：10.1093/aob/mcae001 · 被引用次数：16 · 研究领域：Genetic diversity and population structure、Genomics and Phylogenetic Studies、Plant Diversity and Evolution

BACKGROUND AND AIMS: Biogeographical relationships between the Canary Islands and north-west Africa are often explained by oceanic dispersal and geographical proximity. Sister-group relationships between Canarian and eastern African/Arabian taxa, the 'Rand Flora' pattern, are rare among plants and have been attributed to the extinction of north-western African populations. Euphorbia balsamifera is the only representative species of this pattern that is distributed in the Canary Islands and north-west Africa; it is also one of few species present in all seven islands. Previous studies placed African populations of E. balsamifera as sister to the Canarian populations, but this relationship was based on herbarium samples with highly degraded DNA. Here, we test the extinction hypothesis by sampling new continental populations; we also expand the Canarian sampling to examine the dynamics of island colonization and diversification. METHODS: Using target enrichment with genome skimming, we reconstructed phylogenetic relationships within E. balsamifera and between this species and its disjunct relatives. A single nucleotide polymorphism dataset obtained from the target sequences was used to infer population genetic diversity patterns. We used convolutional neural networks to discriminate among alternative Canary Islands colonization scenarios. KEY RESULTS: The results confirmed the Rand Flora sister-group relationship between western E. balsamifera and Euphorbia adenensis in the Erit...