Standardized genetic diversity-life history correlates for improved genetic resource management of Neotropical trees. Diversity and Distributions, 24 (6). 730-741, which has been published in final form at
Gilliesieae are a South American tribe of Amaryllidaceae characterized by high floral diversity. Given different taxonomic interpretations and proposals for generic and specific relationships, a representative phylogenetic analysis is required to clarify the systematics of this group. The present study provides a framework for understanding phylogenetic relationships and contributing to the development of an appropriate taxonomic treatment of Gilliesieae. Molecular analyses, based on nuclear (ITS) and plastid DNA sequences (trnL-F and rbcL), resolve with strong support the monophyly of the tribe and the differentiation of two major clades. Clade I comprises the genera Gilliesia, Gethyum and Solaria and Clade II includes Miersia and Speea. These well-supported clades are mostly congruent with vegetative and karyotype characters rather than, e.g., floral symmetry. At the generic level, all molecular analyses reveal the paraphyly of Gilliesia and Miersia. Gethyum was found to be paraphyletic, resulting in the confirmation of Ancrumia as a distinct genus. Several instances of incongruent phylogenetic signals were found among data sets. The calibrated tree suggests a recent diversification of the tribe (Pliocene–Pleistocene), a contemporary process of speciation in which instances of hybridization and incomplete lineage sorting could explain patterns of paraphyly and incongruence of floral morphology.
Unraveling the processes involved in the origin of a substantial fraction of biodiversity can be a particularly difficult task in groups of similar, and often convergent, morphologies. The genus Eriosyce (Cactaceae) might present a greater specific diversity since much of its species richness might be hidden in morphological species complexes. The aim of this study was to investigate species delimitation using the molecular data of the globose cacti “E. curvispina”, which harbor several populations of unclear evolutionary relationships. We ran phylogenetic inferences on 87 taxa of Eriosyce, including nine E. curvispina populations, and by analyzing three plastid noncoding introns, one plastid and one nuclear gene. Additionally, we developed 12 new pairs of nuclear microsatellites to evaluate the population-level genetic structure. We identified four groups that originated in independent cladogenetic events occurring at different temporal depths; these groups presented high genetic diversity, and their populations were genetically structured. These results suggest a complex evolutionary history in the origin of globular cacti, with independent speciation events occurring at different time spans. This cryptic richness is underestimated in the Mediterranean flora of central Chile, and thus unique evolutionary diversity could be overlooked in conservation and management actions.
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