Microevolution and invasiveness of Oenothera L. species (subsect. Oenothera, Onagraceae) in Europe

Abstract

A comparative analysis of Oenothera's hybrid species was carried out. The genus Oenothera L. (subsect. Oenothera, Onagraceae) is one of the most widespread American genera in Europe. These species possess a special breeding system (permanent translocation heterozygosity) which promotes the hybridiza tion (also introgressive one) among any species resulting in formation of a hybrid with a constant complex of morphological characteristics. The analysis of hybrid species distribution in Europe using published and original data proved the existence of groups with different degrees of invasiveness. A positive correlation between the degree of invasiveness of the parental species and the invasiveness of hybrid ones was shown. As a rule, the aggressive hybrids originated from aggressive parents. The most aggressive hybrids were formed after a crossing of North American with European species; perhaps such hybridization leads to the heterosis effect among normally isolated genes. The invasiveness of morphologically similar hybrids correlates both with their genetic features and with the abundance of the parental species. The new evolution branch of ring forming species of Evening primroses is distinguished by high invasiveness in comparison with bivalent species. The invasiveness of the model species depends on plant cytotypes.

Plant Invasion Research in Russia: Basic Projects and Scientific Fields

“…Oenothera have a special breeding system (constant translocation heterozygosity) [189], which promotes hybridization (including introgressive hybridization) between any species, leading to the formation of hybrids with a constant combination of morphological characteristics. An analysis of hybrid species distribution in Europe proves the existence of species with different degrees of invasiveness [190]. A positive correlation has been found between the degree of invasiveness displayed by parental species and the invasiveness of their hybrids.…”

“…The invasiveness of morphologically similar hybrids correlates both with their genetic traits and the abundance of parental species. The species invasiveness also depends on the plant cytotype [190]: species with chromosome rings display a higher invasiveness compared with those with bivalent chromosomes.…”

Invasive plant species in the Swedish flora: developing criteria and definitions, and assessing the invasiveness of individual taxa

“…Still, the introduction history of the above Rubus species has been thoroughly discussed by Oredsson (, ) and Tragopogon crocifolius was treated as a recent introduction already by Hylander (). On the other hand, the present list includes a couple of species of Amelanchier and Oenothera which undoubtedly have their closest relatives in North America, but which appear to have evolved in Europe after the introduction of their progenitors to the European continent (Kuklina , Tokhtar et al ). Thus, although these species are usually regarded as alien, they may as well be regarded as endemic to Europe.…”

Hybridogenic Activity of Invasive Species of Asteraceae

“…Interspecific hybridization may also facilitate the naturalization of rare genotypes and cause an increase in their proportion by inverse crossbreeding with alien parent taxa or hybridization between the hybrids themselves. Greater selection advantages for alien alleles should lead to faster replacement of natural alleles through hybridization and slower replacement without hybridization [10]. The period of displacement (substitution) decreases significantly with increasing immigration flow and selective differentiation.…”