Riparian populations of minnesota reed canarygrass (Phalaris arundinacea) are most likely native, based on SNPs (DArTseqLD)

Andrzej K Noyszewski,Barbora Kubátová,Anne Timm,Daša Bastlová,Vojtěch Januš,Jan Květ,Holly Pellerin,Andrzej Kilian,Alan G Smith,Emi Ito,Neil O Anderson,Vladislav Čurn,Diana Dalbotten,Keith R Edwards,Tereza Kávová

doi:10.1007/s11273-021-09795-8

Abstract

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.

Highlights

The challenges of establishing reed canarygrass (RCG; Phalaris arundinacea L.) as a native vs. exotic in North America are paramount as management priorities would change once the status were known (Anderson et al 2021)
The PCoA of 2,521 DArTseqLD Single nucleotide polymorphisms (SNPs) markers shows that all (n = 256) tested extant wild, riparian RCG genotypes from six Minnesota Rivers and six Czech Republic Rivers are genetically distinct (Fig. 3A). Since both PCoA-1 and PCoA-2 axes explain a relatively small percent of SNP genetic variation observed in both populations, 2.9% and 1.5%, respectively, neither a single nor or a few SNPs could be identified that differentiated RCG on the two continents
The additional discriminant analysis of principal components (DAPC) analysis resulted in the formation of two primary clusters separating the Minnesota Rivers and Czech Republic Rivers riparian samples, with almost no overlap (Fig. 3b)

Summary

Introduction

The challenges of establishing reed canarygrass (RCG; Phalaris arundinacea L.) as a native vs. exotic in North America are paramount as management priorities would change once the status were known (Anderson et al 2021). Differential shifts in land management would vary, depending on where the Wetlands Ecol Manage (2021) 29:467–494 species occurs, e.g. Tribal Land Managers would be interested in controlling exotic genotypes while preserving natives (if this is economically feasible), whereas State or Provincial Departments of Natural Resources and private agencies may choose to control aggressive, invasive populations regardless of their native/exotic status (Anderson et al 2021). America in some instances (Piper 1914; Schoth 1929) while others postulate that it is an exotic, invasive varietas from Eurasia (Lavergne and Molofsky 2004). American populations are considered to be a mixture of native N. American and European types or varietas (Lavergne and Molofsky 2007) or the products of recent RCG breeding programs, with cultivars outcompeting native populations (Merigliano and Lesica 1998). RCG’s exotic origin is considered to be a cause of its invasiveness in the State of Minnesota (USA) and wetlands elsewhere (Lavergne and Molofsky 2004)

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