Eupolyploidy as a Modeinplant Speciation

Abstract

When discussing phenomena of the whole genome duplication (WGD), the terms neopolyploid, mesopolyploid, and paleopolyploid are used in their modern “post-genomic” interpretation. In our opinion, in the flow of changing genome states between neopolyploids and paleopolyploids, it makes sense to single out the eupolyploid stage – a state of a polyploid, when its polyploid nature is beyond doubt, but the genome (karyotype) of the eupolyploid, unlike the neopolyploid, is already relatively stable. Most of so-called polyploid plant species are actually eupolyplids, the polyploid nature of the karyotype of which is beyond doubt among researchers – geneticists, karyologists, and florists. Optionally, eupolyploids can enter new rounds of interspecific hybridization with the hybrid maintaining the level of ploidy of the parents or with the emergence of an allopolyploid of a higher level of ploidy. Eupolyploidization of the genome is a radical and rapid method of speciation and genus formation in plants. In this way, tens of thousands of species of modern plants arose. Successful combinations of alleles of eupolyploid subgenomes, large sizes characteristic of high polyploids, frequent transition to asexual reproduction can contribute to the successful development of new areas by eupolyploids, adaptation to extreme conditions of existence at the edge of areas, but not to the acquisition of new aromorphoses – this is speciation, but speciation on already mastered level of evolutionary complexity, a step that does not in itself lead to progressive evolution.