Abstract Detail

Phylogenomics

Phylogenomics of Spanish irises, Iris subgenus Xiphium.

The Spanish irises, Iris subgenus Xiphium, are a relatively small clade of about nine bulbous species that are distributed in southwestern Europe and northern Africa with their center of diversity on the Iberian Peninsula. In general, they occur in rocky soils within Mediterranean habitats that are mesic in spring but dry out by summer, although one species is found in alpine meadows of the Pyrenees. The subgenus has been resolved as monophyletic in studies focusing on the genus, but no study has comprehensively sampled the subgenus or included nuclear as well as plastid data. In this study, phylogenetic relationships among subgenus Xiphium taxa were reconstructed based on sequence data from 110 nuclear markers and whole plastomes using Bayesian inference and maximum likelihood. Plastomes and combined datasets resolved subgenus Xiphium and I. xiphium as not monophyletic while nuclear data resolved the subgenus as monophyletic but I. xiphium as not monophyletic. Topology tests indicated that the alternative hypothesis of a monophyletic subgenus cannot be rejected while a monophyletic I. xiphium can be rejected. It is hypothesized that the subgenus is monophyletic based on these analyses, morphology, and biogeography. Uneven patterns of missing data is considered a likely reason for topological incongruence among datasets. A previously suggested informal group based on cytology and one plastid marker was supported. Patterns of relationships among species suggest multiple exchanges between the African and European continents but also the importance of the Strait of Gibraltar as a barrier to genetic exchange.

1 - University Of California, Berkeley, UC & Jepson Herbaria, 1001 Valley Life Sciences #2465, Berkeley, CA, 94720, United States

Keywords:
biodiversity hotspot
Constraint trees
Iris
Iridaceae
mediterranean basin
missing data
nuclear genes
phylogenomics
plastomes
Strait of Gibraltar
targeted enrichment.

Presentation Type: Oral Paper
Number: PHYLO II013
Abstract ID:773
Candidate for Awards:None