The evolution in the genus Carex (Cyperaceae) - the use of flow cytometry
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Rok publikování | 2011 |
Druh | Konferenční abstrakty |
Fakulta / Pracoviště MU | |
Citace | |
Popis | The genus Carex, sedges, is one of the largest angiosperm genera with worldwide distribution. The sedges have some unique characteristics that make them an interesting model for studying evolution of genomic features such as genome size, AT/GC content and in broader meaning the karyotype. They posses holokinetic chromosomes (they lack centromere) and they show higher rates of chromosomal rearrangments, leading to agmatoploidy and symploidy, then is usual in the most angiosperms. With help of flow cytometric measurments, that became routinely applied in plant taxonomy, it is possible to adress new questions and shed new light on evolution of this genus. We used flow cytometry to measure genome size and AT/GC genomic ratio for 159 species of the genus Carex, chromosome numbers were counted for 96 species (Rotreklova et al., 2011), the rest was adopted from literature (Roalson, 2008). Method of independent contrasts was employed to test relationships in phylogenetic frame based on phylogenetic tree inferred from ITS sequences for 108 species from the NCBI Gen Bank database (Benson et al., 2009). The knowledge of genome sizes and AT/GC contents together with previously known chomosome numbers and phylogenetic relations shed new light on the patterns of chromosomal evolution in related groups of species (e.g. agmatoploidy as a prevalent mode of evolution in section Phacocystis), on the evolution of genome constitution (e.g. massive proliferation of transposable elements in section Aulocystis) and on the taxonomic positions of species (e. g. presumable polyphyly of section Acrocystis, differencies in heterogeneity of two subgenera, subg. Carex and subg. Vignea). |
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