Genetic relationship of Elymus alaskanus, E. caninus, E. fibrosus, and E. mutabilis revealed by chloroplast DNA sequences

Abstract

The genetic diversity of a species measures its genetic variation, or population diversity, which determines evolutionary relationships; high genetic diversity is linked to survival, adaptation and evolution. In this study, nucleotide diversities of chloroplast genes of four Elymus species were determined. Phylogenetic relationship of these four species was obtained using PAUP computer software. The phylogenetic tree, using the rps16 primer pair, produced two distinct clades, one containing Agropyron and Eremopyrum while the other contained many more genera from the Triticeae tribe, including all four Elymus species being studied. The species formed distinct clades with the same populations of that species for most cases. Furthermore, results indicated that, with the rps16 cpDNA gene, an E. caninus population yielded the highest nucleotide diversity while two E. alaskanus populations yielded lowest diversity. Samples tested using the intergenic region trn-tw primer sequences found that a sample from the same E. caninus population as above produced the highest nucleotide diversity. The lowest nucleotide diversity was also detected in an E. caninus population. E. caninus populations demonstrate considerable genetic variability due to their genetic diversity.