Introduction
The Mexican Tiger Irises (genus Tigridia Juss.) are monocots endemic to Mexico that have diversified along the Mexican Transition Zone, a key geographic region of overlap between the Nearctic and Neotropical biotas. Tigridia exhibits striking diversity in floral color, patterning, and morphology that results in the attraction of a wide array of pollinators including hummingbirds, bees, and flies. These floral features also contribute to many Tigridia species being highly coveted in the ornamental trade. Phylogenetic relationships within Tigridia and among its sister lineages are contentious, obfuscating our understanding of the evolutionary history of this charismatic group of monocots. Here we present 38 high-quality genomes for Tigridia and closely related taxa (Figure 1), including species currently placed in the genera Ainea, Alophia, Cardiostigma, Cipura, Cobana, Colima, Eleutherine, Herbertia, Larentia, Nemastylis, and Sessilanthera; with Trimezia selected as an outgroup for evolutionary analyses. These resources will establish a foundation for future phylogenomic and comparative studies to explore the evolution of floral traits within the group, ultimately contributing to our understanding the diversification and endemism of flora that inhabit the Mexican Transition Zone.
Methods
DNA was extracted from leaves that were collected from living material and subsequently dried and stored in silica, with approximately 10-15 mg of leaf tissue used per extraction. Voucher specimens for each species are indicated in Table 1; most vouchers were deposited in the herbarium of the Instituto de Botánica of the Universidad de Guadalajara (IBUG) with Trimezia candida collected from the Liberty Hyde Bailey Conservatory at Cornell and deposited in the L. H. Bailey Hortorium Herbarium (BH). Each DNA extraction was performed using the Qiagen DNEasy genomic extraction kit using the manufacturer’s protocol. Paired-end sequencing libraries were constructed using the Illumina TruSeq kit according to the manufacturer’s instructions. Libraries were sequenced on an Illumina Hi-Seq platform in paired-end, 2 × 150 bp format. The resulting fastq files were trimmed of adapter/primer sequences and low-quality regions with Trimmomatic v0.33 (Bolger et al. 2014). The trimmed sequences were assembled by SPAdes v3.15.4 (Bankevich et al. 2012), screened for foreign contaminants with FCS (Astashyn et al. 2024), followed by a finishing step using Zanfona (Kieras et al. 2021) to scaffold newly generated assemblies based on available genomes from related species. Raw sequencing reads were uploaded to the Sequence Read Archive.
Results and Data Availability
Sequencing files and scaffolded genome assemblies are available on NCBI with the accession numbers listed in Table 1.
Funding
Funding was provided by Iridian Genomes, grant# IRGEN_RG_2021-1345 Genomic Studies of Eukaryotic Taxa.