Geographical parthenogenesis: evolutionary and ecological significance of apomictic reproduction in vascular plants
Geografická parthenogeneze: evoluční a ekologický význam apomiktického rozmnožování u cévnatých rostlin
dissertation thesis (DEFENDED)
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Permanent link
http://hdl.handle.net/20.500.11956/102898Identifiers
Study Information System: 155762
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- Kvalifikační práce [19113]
Author
Advisor
Referee
Dobeš, Christoph
Krahulec, František
Faculty / Institute
Faculty of Science
Discipline
-
Department
Department of Botany
Date of defense
24. 9. 2018
Publisher
Univerzita Karlova, Přírodovědecká fakultaLanguage
English
Grade
Pass
Keywords (English)
asexual reproduction, Baker rule, colonization, distributional success, plasticity, vascular plantsIt has been suggested that polyploidization affects the ecological niche of a species, possibly ultimately leading to a shift in the distribution of the species, such as in geographical parthenogenesis. The phenomenon describes the wider distribution and shift of asexuals towards higher altitudes, northern latitudes and more extreme habitats when compared with their closely related sexual relatives. Several hypotheses have been proposed to explain such patterns with lacking empirical evidence because investigations rather focused on single hypotheses, which were rather tested several times independently on multiple organisms than vice versa. Therefore, the present study aimed to tackle the phenomenon of geographical parthenogenesis from multiple angles, i.e. testing several hypotheses simultaneously using Hieracium alpinum as a model system. In the arcto-alpine Asteraceae H. alpinum sexually reproducing diploid individuals occur in a small isolated area in the Eastern and Southern Carpathians, while apomictically reproducing, i.e. asexual reproduction via seeds, triploid plants occupy the remaining and much larger part of the range from the Balkans to the arctic parts of Europe. This implies that asexual triploids have had some fitness / colonization advantage(s), leading to a replacement of sexual diploids...
It has been suggested that polyploidization affects the ecological niche of a species, possibly ultimately leading to a shift in the distribution of the species, such as in geographical parthenogenesis. The phenomenon describes the wider distribution and shift of asexuals towards higher altitudes, northern latitudes and more extreme habitats when compared with their closely related sexual relatives. Several hypotheses have been proposed to explain such patterns with lacking empirical evidence because investigations rather focused on single hypotheses, which were rather tested several times independently on multiple organisms than vice versa. Therefore, the present study aimed to tackle the phenomenon of geographical parthenogenesis from multiple angles, i.e. testing several hypotheses simultaneously using Hieracium alpinum as a model system. In the arcto-alpine Asteraceae H. alpinum sexually reproducing diploid individuals occur in a small isolated area in the Eastern and Southern Carpathians, while apomictically reproducing, i.e. asexual reproduction via seeds, triploid plants occupy the remaining and much larger part of the range from the Balkans to the arctic parts of Europe. This implies that asexual triploids have had some fitness / colonization advantage(s), leading to a replacement of sexual diploids...