). The content of polysaccharides in plants of the genus Dahlia Cav. introduced in the M. M. Gryshko National Botanical Garden

Abstract

Purpose. To investigate the polysaccharide content of different plant organs from varieties and hybrids of the Dahlia genus introduced to the M. M. Gryshko National Botanical Garden during the growing season. Methods. The quantitative content of polysaccharides was determined by the weight method, while glucose, fructose and sucrose were determined by the chromatographic method. Results. The maximum polysaccharide content in root tubers at the end of the growing season was recorded in ‘Osin v Sofiivtsi’ (101.00 ± 0.1%); the others had values ranging from 67.90 ± 0.1% in ‘Canby Centennial’ to 90.0 ± 0.2% in ‘Kiki Karon’. During storage, these values decreased by almost half for ‘Osin v Sofiivtsi’, ‘Kiki Caron’ and Hybrid No. 150, while remaining at a similar level for ‘Canby Centennial’. The main soluble sugars in the Dahlia cultivars’ roots are glucose, fructose and sucrose. Their total content at the end of the growing season in autumn ranged from 8.0% (‘Canby Centennial’) to 11.5% (Hybrid No. 150). Storing the root tubers for four months in a cool room at a temperature of 5–8 °C and humidity of 50–60% had a positive effect on the soluble sugar content, which increased by 1.3–1.8 times [from 14.72% (‘Canby Centennial’) to 21.86% (Hybrid No. 150)]. The total amount of polysaccharides in the leaves of Hybrid No. 150 did not exceed 6 ± 0.02%, and was even lower in the other varieties: ‘Kiki Canon’ – 2.9 ± 0.01%, ‘Osin v Sofiivtsi’ – 1.8 ± 0.01%, ‘Canby Centennial’ – 1.6 ± 0.01%. Conclusions. Based on the results of the study, it can be concluded that the roots of Dahlia plants, which can retain polysaccharides even in winter, are a potential non-traditional source of these biologically active compounds.