Development of genomic resources for cattails (Typha), a globally important macrophyte genus

1. A critical knowledge gap in freshwater plant research is the lack of genetic tools necessary to answer fundamental questions about their demographic histories, adaptation and phylogenetic relationships. One example of this is Typha, a global genus of freshwater plants foundational to wetlands that also is becoming an increasingly problematic biological invader in numerous regions worldwide; although important insights have been discovered for this genus, existing markers are insufficient to answer fundamental questions about their demographic histories, adaptation and phylogenetic relationships; to identify introduced and hybrid lineages; and to examine patterns of hybridisation and introgression. 2. We optimised a library preparation and data processing protocol to develop genome-wide nuclear and plastid resources for studying the evolutionary history, genetic structure and diversity, hybridisation, local adaptation, invasiveness, and geographical expansion dynamics of Typha. 3. We sequenced 140 Typha samples and identified similar to 120 K nuclear single nucleotide polymorphisms (SNPs) that differentiate T. angustifolia, T. domingensis and T. latifolia, and retrieved their plastome sequences. We observed genetic introgression among the three species. 4. Following a fast, straightforward and cost-efficient genomic library preparation protocol, we produced a suite of genome-wide resources to facilitate investigations into the taxonomy and population genetics of Typha and to advance the genomic understanding of wetland plants. 5. The protocol described, the updated chromosome-level genome assembly of T. latifolia, the catalogue of species-specific SNPs, and the chloroplast sequences produced in this study comprise permanent resources that can be applied to study the genetic composition of multiple populations and hybrid zones, and will be incorporated into future studies of Typha, an ecologically important and globally invasive macrophyte.