The native vs. exotic status of reed canarygrass (RCG), a major invasive species of Minnesota wetlands, is unknown. The aim of this study was to investigate this native vs. exotic status to enhance its management. Genetic comparison of wild RCG populations from six Minnesota and six Czech Republic rivers was performed. A total of 2521 polymorphic SNP markers (single nucleotide polymorphisms) were used to evaluate 478 RCG samples across all collections. In the PCoA, all (n = 256) tested extant wild, riparian RCG genotypes from six Minnesota Rivers and six Czech Republic Rivers were genetically distinct, although some SNPs were common in both populations since they are the same species. DAPC analysis also resulted in the formation of two primary clusters separating the Minnesota Rivers and Czech Republic Rivers riparian samples, with little overlap; STRUCTURE analysis also supported this clustering with k = 4 groups as it separated the Czech Republic Rivers populations into three groups, along with Minnesota Rivers. The uniformity of PCoA, DAPC, STRUCTURE, and Evanno results indicates the distinct separation of Minnesota Rivers and Czech Republic Rivers populations. Portions of the genome (specific SNPs) are preserved or in common across continents, as indicated by STRUCTURE similarities. Nonetheless, overall significant SNP differences between the continents indicate that the Minnesota riparian populations are distinct enough from the European (Czech) collections to be delineated as native N. American RCG. PCoA of all the Minnesota RCG collections clustered Minnesota Rivers, Herbarium, Extant Herbarium, Research Field and Native Field collections together. STRUCTURE analysis (k = 2; Evanno) divided these Minnesota collections from the Commercial Field and Cultivars collections. There are two genetically distinct groups of RCG in Minnesota and since the Minnesota Rivers, the Research Field, the Native Field and pre-1930 herbaria collections clustered together, they are most likely native N. American types. Analysis of molecular variance (AMOVA) indicated that the genetic variation was more significant within, rather than among, the RCG populations. Native, historic herbaria types cluster together with all wild RCG river populations in Minnesota, all of which were distinct from those in Central Europe, suggesting native RCG type persistence in N. America. Also, cultivated forage types of RCG are distinct from wild RCG Minnesota river populations. The SNP genetic data shows that riparian Minnesota RCG populations are native. These data will facilitate future management strategies to control RCG as a native, but invasive, species.
Bibliographical noteFunding Information:
This research was supported by grants from the: Minnesota Invasive Terrestrial Plants and Pests Center (MITPPC; 2017–2020); Czech-US American Science Information Center (AMVIS), Ministry of Education, Czech Republic, Program KONTAKT II, project LH11039; Grant Agency of the University of South Bohemia in Českě Budějovice (GAJU 063/2013/Z); project Postdoc USB (Reg. No. CZ.1.07/2.3.00/30.0006) realized through the European Union Education for Competitiveness Operational Programme; United States, Department of State, Bureau of Educational and Cultural Affairs, J. William Fulbright Scholar Program and an Undergraduate Research Opportunities Program grant (UROP, 2019). Collection of samples along Minnesota rivers were under the auspices of a 2012 State of Minnesota, Department of Natural Resources, Division of Ecological & Water Resources, Scientific and Natural Areas Program Collection Permit. We would also like to thank the Bell Museum (University of Minnesota) for allowing destructive sampling and providing historic RCG samples; special thanks to Drs. Michael D. Casler and Andrew Jakubowski for their consultations regarding published research using historic herbaria samples. Additional thanks are extended to Alli Graper, Kaylie Niedźwiecki, and Sarah Gardner for their help in laboratory work.
© 2021, The Author(s).
- Genotyping by sequencing methods
- Herbaria specimens
- Native species
- Population structure
- Single nucleotide polymorphisms (SNPs)