Morphological variability between diploid and tetraploid taxa of the genus Betula L. in the Czech Republic

Abstract

The aim of this work was to suggest a reliable method for distinguishing between diploid and tetraploid taxa of the genus Betula Linnaeus, based on leaf measurements. In total, 97 individuals from 6 locations within the Bohemian Forest region (Czech Republic) were selected. Four leaves from each individual were evaluated. On each leaf, twenty parameters were measured. Each sample was analysed by flow cytometry to determine its actual ploidy. Measured parameters were analysed by principal component analysis and tested for differences between diploid and tetraploid taxa. For actual ploidy prediction, a classification function was designed. The reliability of the classification function was verified on samples from three different regions of the Czech Republic and compared with functions as suggested by other authors. The classification function designed in this work (based on 3 parameters - blade width in the upper 1/4 of blade length, first vein angle and number of leaf teeth between 3rd and 4th vein) correctly determined actual ploidy in 89% of all tested samples.

Keywords

• silver birch
• downy birch
• ploidy
• flow cytometry
• classification function