TAXON 66 (5) • October 2017: 1017–1040 Majeský & al. • Apomictic taxa in current taxonomy REVIEW How apomictic taxa are treated in current taxonomy: A review Ľuboš Majeský,1 František Krahulec2 & Radim J. Vašut1 1 Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic 2 Institute of Botany, Academy of Science of the Czech Republic, 252 43 Průhonice, Czech Republic Author for correspondence: Ľuboš Majeský,
[email protected] ORCID FK, http://orcid.org/0000-0001-7706-1723; RJV, http://orcid.org/0000-0001-6882-5509 DOI https://doi.org/10.12705/665.3 Abstract Gametophytic apomixis (asexual seed formation without syngamy of female and male gametes) is a highly interesting mechanism for researchers in plant biotechnology, genetics, evolutionary biology, and taxonomy. Apomixis evolved repeatedly and independently in the evolution of multiple genera. It is an effective reproduction barrier and, consequently, conserved apomictic genotypes may become overrepresented in nature. Apomictic plants may easily colonize free niches with only one or a few individuals and outcompete outcrossing plants. In spite of the indisputable pros of asexual reproduction, apomixis also has several cons. One of the most commonly mentioned is the accumulation of deleterious mutations in asexual lineages and decreased genetic variation. However, apomicts in general can be genetically highly diverse. The most common sources of this variation are the accumulation of mutations, hybridization with sexual plants, and facultative apomixis. Facultative apomicts are highly variable in their level of residual sexuality, which increases their genotypic and phenotypic variation. Even in the case of obligate apomicts, gene flow is possible due to functional male meiosis and the production of viable pollen grains by apomicts.