Chromosome evolution in marginal populations of Aegilops speltoides: causes and consequences

Abstract

Considerable genomic variation at the chromosomal level was found in the marginal populations of Ae. speltoides. It is likely that a specific combination of gene mutations and chromosomal repatterning has produced the evolutionary trend in each specific case, i.e. for a particular species or group of related species in a given period of time and in a certain habitat. The appearance of a new chromosomal pattern is considered an important factor in promoting the emergence of interbreeding barriers.

Reticulate Evolution of the Rye Genome

“…In the sedge species Carex curvula, it has been postulated that interspecies hybrid formation could have provided an advantage under changing environmental conditions (Choler et al, 2004). Furthermore, chromosomal aberrations and spontaneous aneuploidy were observed to occur at higher frequency in Aegilops speltoides populations in marginal environments (Belyayev and Raskina, 2013).…”

Genotype- and Cell-Specific Dynamics of Tandem Repeat Patterns in <b><i>Aegilops speltoides</i></b> Tausch (Poaceae, Triticeae)

“…Thus, the artificial population of parental and F 1 and F 2 plants uncovers the ongoing processes in the wild, where under the influence of the changing environment, high recombination frequency in distal/terminal heterochromatic regions accompanies intraspecific diversification in Ae. speltoides , particularly in the case of allopatry, which prevents gene flow [Raskina et al, 2011;Belyayev and Raskina, 2013].…”

“…1 ) [Sears, 1941;Zohary and Imber, 1963;Kimber and Feldman, 1987], which coexist in mixed panmictic populations with different ratios, likely reflecting the environmental conditions. Plants with intermediate ligustica/aucheri phenotypes have been observed as well [Belyayev and Raskina, 2013], suggesting genetic changes within the linked group of genes.…”

Central-marginal population dynamics in species invasions

“…There are more studies that have specifically focused on marginal than central populations (i.e., effects of marginality; e.g., Grant and Antonovics, 1978;Furlow, 1995;Mandak et al, 2005;Kawecki, 2008;Belyayev and Raskina, 2013). Several reasons make studies on species' borders intriguing: (1) marginal populations are more sensitive to environmental changes, (2) marginal populations can indicate that a species' ecological requirements are in equilibrium with properties of the environment (Hengeveld, 1990), (3) species borders discriminate best between conditions favorable for the species and those that are not, (4) marginal habitats provide ideal sites to study species interactions (competition, hybridization, predation; e.g., Whitham et al, 1999), and finally (5) marginal conditions can indicate potential ranges for species invasion and species transplantation.…”

“…Traditionally, most central-marginal (C-M) comparisons have been conducted on native species, especially for conservation purposes (e.g., Channell and Lomolino, 2000;Angert, 2006;Yakimowski and Eckert, 2007;Angert et al, 2008;Eckert et al, 2008;Doak and Morris, 2010;Hardie and Hutchings, 2010;Belyayev and Raskina, 2013; but see Mandak et al, 2005;Leger et al, 2009). Earlier findings from such comparisons include that central populations are larger, more primitive, and more stable than marginal ones (e.g., Williams et al, 2003).…”