Variation in the Festuca brachyphylla (Poaceae) complex in Svalbard, elucidated by chromosome numbers and isozymes

Abstract

Contrasting with former taxonomic treatments, chromosome numbers and isozyme data support the delimitation of the seminiferous representatives of the Festuca brachyphylla complex in Svalbard into four species: R baffinensis, E brachyphylla, E hyperborea and E edlundiae. Unique enzyme markers were found for all species. Festuca brachyphylla proved hexaploid, and the others, tetraploid. The chromosome numbers of R hyperborea and E brachyphylla (as circumscribed at present) are new to Svalbard. Festuca buffinensis is the most distinct species within the complex, probably representing a separate evolutionary lineage. The three other species seem closely related, showing mutually equidistant relationships. Some deviating plants found on disturbed ground might represent hybrid derivatives or an introduced foreign strain of the elsewhere variable E brachyphylla. Materials of diploid R ovina from northern Fennoscandia was enzymatically closely related to the E brachyphylla complex in Svalbard. Festuca brachyphylla, R edlundiae, and E hyperborea all had a stronger affinity to R ovina than to R baffinensis, indicating that the R brachyphylla complex is an artificial taxonomic group. There are reasons t o believe that the origin of the polyploid taxa of the R brachyphylla complex can be traced to diploid species of the E brachyphylla and R ovina complexes.

DNA Barcoding the Canadian Arctic Flora: Core Plastid Barcodes (rbcL + matK) for 490 Vascular Plant Species

“…Festuca baffinensis , F. brachyphylla , F. hyperborea , and F. edlundiae have been called the F. brachyphylla complex [ 122 ]. Festuca baffinensis is distinguished from the remainder of the complex by the barcode loci ( Figure S52 ), a finding consistent with other morphological and molecular research [ 246 , 247 ]. Barcode variation among the remaining taxa is represented by a few haplotypes shared among species ( Figure S52 ).…”

“…Barcode variation among the remaining taxa is represented by a few haplotypes shared among species ( Figure S52 ). Hybridization and/or introgression among the morphologically similar and closely related F. brachyphylla , F. edlundiae , and F. hyperborea [ 122 , 247 ] has been documented in Svalbard [ 246 , 247 ], and hybridization and introgression is also likely among these species in the North American Arctic, which may be the cause of their shared plastid barcode haplotypes. Festuca brevissima , a Beringian taxon that is distinct from other taxa in the North American F. ovina complex based on isozyme data [ 242 ], is not distinguished by the barcode data.…”

The Saxifraga rivularis complex in Svalbard: Molecules, ploidy and morphology

“…Combination of detailed molecular and morphological analyses can be a powerful tool for unravelling complex low-level taxonomy (e.g., Fjellheim et al, 2001;Guldahl et al, 2001;Hansen et al, 2000;Marhold et al, 2002;Scheen et al, 2002). In this paper, we analyzed variation in chromosome number and DNA content (using flow cytometry), two types of molecular markers (RAPDs and isozymes), and 59 morphological characters along transects in two large, mixed Svalbard populations of tentative S. rivularis and S. hyperborea.…”

The flora of Cunningham Inlet, Somerset Island, Nunavut: history, analysis, and new collections of vascular plants, mosses, lichens, and algae

“…Dwarf plants with a heavily marcescent habit, Festuca edlundiae, were first differentiated from the phenotypically variable Festuca hyperborea Holmen ex Frederiksen (High Arctic Fescue) based on isozymes (Aiken et al 1995). Hybridization and introgression between Festuca edlundiae and the other high Arctic Festuca species have been documented (Saarela et al 2013), but taxonomic boundaries between the various species are well understood and various keys exist separating the species using consistent morphologic characters (Fjellheim et al 2001;Guldahl et al 2001). using these keys, it may yet be found that Festuca edlundiae has been collected on Somerset Island before its recognition as a distinct taxon; nonetheless Sokoloff 128 is the first known report of this grass species on the island.…”