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.

Isoenzyme variation and genetic affinities among five Festuca species of section Aulaxyper Dumort.

“…and Festuca within type subgenus Festuca. There are many studies on species belonging to section Festuca, including chemosystematic ones [1][2][3]15] but the species of section Aulaxyper are rather neglected. For this reason we choose species belonging to section Aulaxyper (type F. rubra) which is among the most primitive sections of thin-leaves fescues.…”

“…Electrophoretic methods for isoenzyme analysis testified their value to resolving systematic and evolutionary problems on species and subspecies level [6,14]. In the last two decades several isoenzyme studies of subarctic/arctic [1][2][3]15] and temperate zone fescues [19] were conducted in attempt to investigate species delimitation based on isoenzyme markers.…”

Genetic Structure and Affinity among Xerophyte Taxa of Festuca pseudovina Group (Poaceae)

“…In older taxonomic treatments, they have been considered as forms of F. Isoenzymes are reliable genetic markers as the specificity in their electrophoretic patterns provides a useful tool for evaluating genetic differences and systematic relationships within taxonomically complicated plant groups. In the last two decades, several isoenzyme studies of sub/arctic [ 6,7 ] and temperate zone fescues [ 8,9 ] were conducted in attempt to investigate species delimitation in genus Festuca by means of isoenzyme markers.…”