Morphological and genetic data for Phragmites australis along the Colorado River and in tributaries from southern Utah to west-central Arizona

These data were compiled to provide land-management relevant information on the native and nonnative subspecies (subsp.) of Phragmites australis (subsp. americanus and subsp. australis, respectively) in Glen Canyon National Recreation Area (NRA), Grand Canyon National Park (NP), Arches National Park, and Bill Williams National Wildlife Refuge. Specifically, the goals of this work were to determine the extent and distribution of Phragmites australis subspecies in the Glen and Grand Canyon regions, evaluate if P.a. subsp. americanus can be reliably distinguished from P.a. subsp. australis using morphological characters in this region, and determine if P.a. subsp. americanus exhibits genetic structure in the study area. The objectives of our study were to determine how prevalent the nonnative Phragmites is in the study area and support native plant material development for restoration activities in Glen Canyon NRA and Grand Canyon NP. These data represent real-time PCR cycle threshold values (Ct scores) for two target regions, nuclear microsatellite data for seven loci, and morphological data. These data were collected for 84 sites including five nonnative Phragmites locations and 79 native Phragmites locations. Tissue samples were mostly collected along the Colorado River between Glen Canyon Dam and Lake Mead, around Lake Powell, and in tributaries to the Colorado River from 2021 through 2024. Tissue samples and herbarium collections were collected from one to fifteen ramets across each stand, where multiple samples from one stand were spread across its full area. Reference samples for both the native and nonnative Phragmites, Phragmites australis subsp. berlandieri, and a hybrid of P.a. australis and P.a. americanus were acquired and included in analyses. Samples were dried and total genomic DNA was extracted using Qiagen DNeasy Plant MiniKits. Real-time polymerase chain reactions (PCR) with two target regions, AMER and AMAU, were used to identify nonnative Phragmites individuals (Lindsay et al, 2023). We then amplified 7 microsatellite loci (Saltonstall, 2003; Meyerson and others, 2010) using PCR and analyzed the fragments on an ABI 3730XL Genetic Analyzer with GeneScan LIZ500 internal size standard. Although P. australis is polyploid, these loci all had no more than two alleles, so were treated as diploid data. We then collected field and lab data on morphological characters for the stands we genetically tested, following previously described diagnostic characters (Swearington and Saltonstall, 2012; McTavish et al, 2023) These data can be used to evaluate if a stand of Phragmites is nonnative, native, or a hybrid of the two. It can also be used to determine genetic diversity and structure across the sampled stands. Finally, they can be used to assess morphological variability in native Phragmites stands across the region.