Calceolariaceae809: A bait set for targeted sequencing of nuclear loci

Premise

The genus Calceolaria (Calceolariaceae) is emblematic of the Andes, is hypothesized to have originated as a recent, rapid radiation, and has important taxonomic needs. Additionally, the genus is a model for the study of specialized pollination systems, as its flowers are nectarless and many offer floral oils as a pollination reward collected by specialist bees. Despite their evolutionary and ecological significance, obtaining a resolved phylogeny for the group has proved difficult. To address this challenge, we present a new bait set for targeted sequencing of nuclear loci in Calceolariaceae and close relatives.

Methods

We developed a bioinformatic workflow to use incomplete, low-coverage genomes of 10 Calceolaria species to identify single-copy loci suitable for phylogenetic studies and design baits for targeted sequencing.

Results

Our approach resulted in the identification of 809 single-copy loci (733 noncoding and 76 coding regions) and the development of 39,937 baits, which we validated in silico (10 specimens) and in vitro (29 Calceolariaceae and six outgroups). In both cases, the data allowed us to recover robust phylogenetic estimates.

Discussion

Our results demonstrate the appropriateness of the bait set for sequencing recent and historic specimens of Calceolariaceae and close relatives, and open new doors for further investigation of the evolutionary history of this hyperdiverse genus.