Independent Evolutionary Lineages in a Globular Cactus Species Complex Reveals Hidden Diversity in a Central Chile Biodiversity Hotspot

Abstract

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.

Taxonomic dissection based on molecular evidence of the Eriosyce curvispina complex (Cactaceae): identifying nine endemic species from Central Chile

“…We incorporated 22 new samples, each sequenced for five markers, thereby contributing with 110 new sequences. This complements sequences previously published by our team in Guerrero et al (2019b) and Villalobos-Barrantes et al (2022) . We collected plant fresh tissue from roots or flowers mainly and kept them in CTAB-NaCl buffer (2%:22%) to transport to the laboratory and store at -80 °C until the extraction.…”

“… Kattermann (1994) merged Backeberg’s genera Horridocactus and Neochilenia into his Eriosyce section Neoporteria , subsection Horridocactus , which includes 14 species from south-central to northern Chile. Conversely, the findings of Villalobos-Barrantes et al (2022) supported the monophyly of the Eriosyce section Horridocactus , which is circumscribed to include the following nine species: E. armata (F.Ritter) P.C.Guerrero & Helmut Walter, E. aspillagae (Söhrens) Katt., E. cuvispina (Bertero ex Colla) Katt., E. duripulpa (F.Ritter) P.C.Guerrero & Helmut Walter, E. engleri (F.Ritter) Katt., E. garaventae (F.Ritter) Katt., E. jussieui (Monv. ex Salm-Dyck) P.C.Guerrero & Helmut Walter, E. limariensis (F.Ritter) Katt.…”

“…A recent study by Villalobos-Barrantes et al (2022) included the nine species of Horridocactus provided new evidence by incorporating new locations and a new population scale molecular dataset (12 new pairs of nuclear microsatellites, SSR). This significantly enhanced our understanding of the evolutionary relationships among the species of the Eriosyce section Horridocactus .…”

Towards a unified taxonomic catalogue for the Chilean cacti: assembling molecular systematics and classical taxonomy

“…were not supported by the results of Guerrero et al (2019b) (see Table 2). In addition, the taxonomic delimitation of E. curvispina Bertero ex Colla including several infraspecies did not resist standing upright much longer, by not complying with the principle of monophyly as reported by Guerrero et al (2019b), and by new molecular data of several putative members of the E. curvispina complex (Villalobos- Barrantes et al 2022).…”

Revisiting phylogeny, systematics, and biogeography of a Pleistocene radiation

“…Multilocus approaches under the multi‐species coalescent (MSC) model are recommended to resolve phylogenies in the context of rapid diversification because they accommodate gene tree heterogeneity due to incomplete lineage sorting, commonly observed in such scenarios (Whitfield and Lockhart, 2007; Edwards et al, 2016). This approach is particularly critical in phylogenetic studies within the Cactaceae family, which has undergone pulses of rapid diversification since the Miocene to Pleistocene epochs (Arakaki et al, 2011; Bonatelli et al, 2014; Hernández‐Hernández et al, 2014; Magallón et al, 2015; Amaral et al, 2021; Majure et al, 2021; Merklinger et al, 2021; Villalobos‐Barrantes et al, 2022).…”