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Variation and interspecific hybridization of Elymus repens and E. hispidus
Bartošová, Romana ; Urfus, Tomáš (advisor) ; Chrtek, Jindřich (referee)
Family Poaceae is one of the most derived groups of monocots. Major mechanisms of grasses evolution and particularly of tribe Triticeae and genus Elymus are polyploidisation and hybridisation. Presented diploma thesis assessed frequency and direction of hybridisation between Elymus hispidus and E. repens in Central Europe. Thesis also evaluated evolutionary importance (significantly higher ratio of hybridisation and polyploidisation) of hybrid swarm in Nature Reserve Čertoryje (Bílé Karpaty Mountains/the White Carpathians, the Czech Republic). Putative hybridizing populations were 14,4 % of sampled localities, i.e. direct presence hybrids (7,9 %) or both parental species (8,4 %). Aneuploids and higher polyploids were found exclusively in Čertoryje hybrid swarm, except one putative DNA nonaploid plant. The genome in situ hybridisation confirmed and improved knowledge of particular species/cytotypes chromosome counts and further specified their genome composition. GISH newly characterized genome composition of interspecific hybrids and higher allopolyploids and revealed their heterogeneous origin. Flow cytometry revealed continuum of absolute genome sizes among parental species and their hybrid. The continuum was rather asymmetric in direction towards E. hispidus. Model hybrid swarm Čertoryje produce...
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Variation and interspecific hybridization of Elymus repens and E. hispidus
Bartošová, Romana ; Urfus, Tomáš (advisor) ; Chrtek, Jindřich (referee)
Family Poaceae is one of the most derived groups of monocots. Major mechanisms of grasses evolution and particularly of tribe Triticeae and genus Elymus are polyploidisation and hybridisation. Presented diploma thesis assessed frequency and direction of hybridisation between Elymus hispidus and E. repens in Central Europe. Thesis also evaluated evolutionary importance (significantly higher ratio of hybridisation and polyploidisation) of hybrid swarm in Nature Reserve Čertoryje (Bílé Karpaty Mountains/the White Carpathians, the Czech Republic). Putative hybridizing populations were 14,4 % of sampled localities, i.e. direct presence hybrids (7,9 %) or both parental species (8,4 %). Aneuploids and higher polyploids were found exclusively in Čertoryje hybrid swarm, except one putative DNA nonaploid plant. The genome in situ hybridisation confirmed and improved knowledge of particular species/cytotypes chromosome counts and further specified their genome composition. GISH newly characterized genome composition of interspecific hybrids and higher allopolyploids and revealed their heterogeneous origin. Flow cytometry revealed continuum of absolute genome sizes among parental species and their hybrid. The continuum was rather asymmetric in direction towards E. hispidus. Model hybrid swarm Čertoryje produce...
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Generic classification in the tribe Triticeae focused on couches (Elymus L.) in Central Europe
Bartošová, Romana ; Krahulec, František (advisor) ; Chrtek, Jindřich (referee)
Tribe Triticeae is a polyphyletic taxon in the Poaceae family which contains both perrenial and annual species, cultivated cereal crops (Triticum, Secale, Hordeum) and weeds (Elymus, Elytrigia, Aegilops). The tribe was first recognized and described at the beginning of 19th century and its genera composition have been changed many times since. As the tribe's genera are not monophyletic, its interpretation is problematic and it is also difficult to clarify evolutionary relationships among genera and species mainly in genus Elymus. Historical classification of species Elymus repens and Elymus hispidus is difficult due to morfological similarities and genomic divergence. These species are classified into many genera. Species' genome analyses were first performed in the 30's of 20th century mainly within the research of plant breeding and hybridization among cultivated cereal crops and species of distinct genera. The most important and complete papers with species and genera genome combinations were published by Löve and Dewey. Other plant scientists continued in their footsteps. Genome constitutions of all allopolyploids of Triticeae are not yet known. There is no satisfactory classification of the tribe which would well characterize their fylogenetic relationships.
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