Introduction
Mountain Avens (Dryas spp. Rosaceae) is a circumpolar genus of about fifteen species of wind-dispersed, self-incompatible dwarf shrubs that are distributed throughout the Arctic and Alpine regions of the northern hemisphere (Springer and Parfitt 2015; http://www.itis.gov). Dryas is primarly referenced as a classic palynological indicator of past climate (i.e. Younger Dryas stadial). As an abundant and charismatic floristic element of arctic ecosystems, species of Dryas are the official plants of the Northwest Territories, Canada and Iceland.
Here we present the first genome assemblies for three species of Dryas occurring in interior Alaska. The taxonomy of Dryas is in desperate need of taxonomic revision. The nomenclature we use here follows the Flora of North America (Springer and Parfitt 2015).
Dryas alaskensis Porsild (DAL) grows in Alaska and the Yukon Territories and D. ajanensis ssp. beringensis Jurtzev (DAJ) occurs from the Northwest Territories into Chukotka Autonomous Okrug, Russia. The ecology of DAL and D. ajanensis ssp. beringensis (DAJ) has been carefully studied to understand how they have persisted in sympatry. The two species are readily distinguished by differences in leaf size and leaf pubescence as well as microhabitat, with DAL occupying moist, ‘snowbed’ sites and DAJ occupying dry, rocky, exposed, ‘fellfield’ sites (McGraw and Antonovics 1983). The species have distinct flowering times and significant genetic differentiation as interpreted from allozyme (Max, Mouchaty, and Schwaegerle 1999) and genotyping by sequencing data (Stasinski et al. 2021). The third species, D. integrifolia Vahl., is widely distributed in Alaska, Canada, and the Russian far-east.
A genome for the other North American species, Dryas drummondii was published in 2018 as part of an investigation into the biology of nitrogen fixation in root nodules (Griesmann et al. 2018). These genome assemblies will add to the growing resources available to study this phenomenon as well as the taxonomy, ecology, evolution, and conservation of Dryas plants.
Methods
Leaf tissue from wild plants was extracted using the Qiagen Plant DNAeasy kit according to the manufacturer’s instructions. A paired-end sequencing library was constructed using the Illumina TruSeq kit according to the manufacturer’s instructions. The library was sequenced on an Illumina Hi-Seq platform in paired-end, 2 × 150 bp format. The resulting fastq files were trimmed of adapter/primer sequence and low-quality regions with Trimmomatic v0.33 (Bolger, Lohse, and Usadel 2014). The trimmed sequence was assembled by SPAdes v2.5 (Bankevich et al. 2012) followed by a finishing step using Zanfona (Kieras, O’Neill, and Pirro 2021).
Results and Data Availability
Raw sequence reads and assembled genomes were deposited to Genbank’s SRA and Genomes submission pipelines.
Funding
Funding was provided by Iridian Genomes, grant# IRGEN_RG_2021-1345 Genomic Studies of Eukaryotic Taxa.
Dawson White is supported by the Grainger Bioinformatics Center at the Field Museum and an NSF Postdoctoral Fellowship in Biology, award 2010821.