An integrative approach for species delimitation in a species complex of Eryngium (Apiaceae) endemic to Chile

PADIN A. L.; CALVIÑO, C. I.

Congreso; II Virtual Meeting of Systematics, Biogeography and Evolution; 2021

Species delimitation impacts on most elds of biology, including biogeography, phylogenetics, ecology and conservation. Species complexes include phylogenetically closely related species whose boundaries are unclear, posing enormous challenges for species delimitation. The Eryngium anomalum species complex comprises a group of annual herbs that are found along coastal areas of central-northern Chile. Based on current taxonomy this complex includes two species that are morphologically very similar. Recent phylogenetic studies estimated that the species complex is monophyletic, however, the species that comprise it probably are not, casting doubts on their limits. Moreover, based on qualitative characteristics of the fruits, we recognized dierent morphotypes, suggesting the presence of an additional new species within the complex. In this study, we tested the hypothesis that the Eryngium anomalum complex comprises three species (not two) through an integrative taxonomic approach using morphological, geographic distribution, climatic, and molecular data. For that, we analyzed quantitative morphological characters and climatic variables using uni- and multivariate statistics on 181 individuals from herbarium specimens of the Eryngium anomalum species complex. We also analyzed their geographic and altitudinal distributions using georeferenced localities indicated on the specimen labels. In addition, we tested hypothesis of species delimitation based on chloroplast and nuclear DNA sequence data from eight regions using two Bayesian coalescent-based methods: Bayes factors (BF) and Bayesian phylogenetics and phylogeography (BPP) estimation. The dierent lines of evidence examined, i.e. morphology, climatic niche, altitudinal and geographical distribution, and genetic, support the recognition of three dierent species within the Eryngium anomalum complex. The integrative approach followed in this study allowed robust hypotheses of species limits within a species complex. In turn, this grants solid grounds for future studies or policies on conservation, biogeography, ecology, and many others.