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Morphological variability of birch genus (Betula L.) in chosen regions of the Czech Republic with a focus on tetraploid taxa
Linda, Rostislav ; Kuneš, Ivan (advisor) ; Jana, Jana (referee)
The aim of this work is to propose reliable method for distinguishing between diploid (2n) and tetraploid (4n) taxa of the genus Betula L., based on leaf measurements. These measurements are realized by common tools, such as ruler or protractor. Main advantage of these methods is that they can be applied even in the field. The further aim of work is to describe and evaluate genetic variability within tetraploid taxa, whose taxonomic relationships are still unclear and under discussions.
For statistical analysis, 97 individuals from 6 localities within Šumava region were selected and 4 leaves from every individual were analysed. In total, 20 parameters were measured on every leaf (16 quantitative and 4 qualitative). Each individual was also analysed by flow cytometry method to determine real genome size (ploidy).
Differences in selected parameters between individuals with different ploidy were statistically tested. Significant results were observed in 12 of 16 quantitative and 2 of 4 qualitative parameters. For real ploidy prediction, the classification function was designed, whose reliability was 96 % for the primary data.
The reliability of classification function was verified on samples from three different regions within the Czech Republic and compared with functions suggested by other authors. Function designed in this work was able to correctly determine real ploidy in 89 %, which is the most of all compared functions.
Genetic variability, especially within tetraploid taxa is mentioned in relation to other author's previous studies. Distinguishing between B. pubescens and B. carpatica was not possible using selected genetic markers. Genetic conformity of these taxa is also mentioned in publications of foreign authors, as contrasted to Czech literature, which generally distinguishes B. pubescens and B. carpatica as separated species.
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