Page 148 - Book of Abstracts

5 International Scientific Online Conference DOI: https://doi.org/10.15414/2021.9788055224015

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PHYTOCHEMISTRY AND FLOWER'S MORPHOLOGY OF INVASIVE SOLIDAGO L. SPECIES –
VALUABLE LATE AUTUMN MELLIFERS
Yulia Vinogradova, Olga Shelepova
N.V. Tsitsin Main Botanical Garden of Russian Academy of Sciences, Moscow, Russian Federation;
E-mail.: gbsad@mail.ru
In Europe, two alien North American species of Solidago L. have been detected: S.
canadensis L. and S. gigantea Ait. Both species provide a stable late harvest and are valued by
beekeepers for their ability to produce pollen and nectar in late fall. This honey is rarely
pumped because all of the nectar and pollen goes to support the bee colonies and prepare them
for wintering. Goldenrod honey yields up to 150 kg per hectare. Germacren D, which has not
been identified in other monofloral kinds of honey, is present in goldenrod honey. Although
there is no complete similarity between the chemical components of Solidago flowers and
goldenrod honey, there is a significant correlation. Honey absorbs the medicinal qualities of the
plant from which it is collected, so the study of the phytochemical composition of inflorescences
(heads) seems to be very actual. The work aims to determine the total content of saccharides,
phenolic compounds, and flavonoids in flowers of S. canadensis and S. gigantea for comparative
evaluation of bee production quality, and also to specify morphometric differences in the
structure of flowers and heads of both species.
The heads in the phase of mass flowering were collected in the Moscow Region. The total
content of phenolic compounds was determined using the Folin-Ciocalteu method. To evaluate
the morphometric characters, plants growing in the same agricultural background were
selected, the sample consists of 50 heads for each species; studied parameters (length and
diameter of the head, length of the involucre) were measured using a digital electron
microscope Keyence VHX 1000. The total content of the saccharides in S. canadensis heads was
27.33 ±0.54 %, with monosaccharides ~44–46 %. In S. gigantea’s heads total content of the
saccharides was 1.5 times lower – 18.07 ±0.73 %, the content of mono sugars was 7.39 ±0.15
%. The total content of phenolic compounds in the heads of S. canadensis was 105.36 ±1.45 mg
GAE/100 g and in S. gigantea’s heads was 98.41 ±1.71 mg GAE/100 g. The total flavonoid
content as quercetin equivalents was 58.23 ±0.17 mg QE/100 g in the heads of S. canadensis
and 41.97 ±0.34 mg QE/100 g in S. gigantea’s heads. For S. gigantea the head’s length was 5.2–
7.7 mm (on average 6.4 ±0.1 mm; V=11 %), the head’s diameter was 2.0–3.0 mm (2.3 ±0.0 mm;
V=9 %), the involucre’s length was 2.9–4.4 mm (3.7 ±0.1 mm; V=11). For S. canadensis, these
parameters are significantly lower: the head’s length was 3.5–5.2 mm (in average 4.4 ±0.1 mm;
V=11 %), the head’s diameter 1.5–2.1 mm (1.8 ±0.0 mm; V=6 %), the involucre’s length was
2.6–3.9 mm (3.1 ±0.1 mm; V=8 %). However, the relative size of the involucre, on the contrary,
is higher in S. canadensis – it is 70 % of the head’s length, while in S. gigantea the involucre is
60 % of the head’s length. In Central Europe, S. canadensis occurs more frequently than S.
gigantea and prefers drier and warmer habitats.
It is not advisable to intentionally cultivate Solidago species as melliferous plants. In some
European countries, there is even a fine for this. Both S. canadensis and S. gigantea are
aggressive invasive species and can displace valuable native honey plants from natural
phytocenoses.
Keywords: Solidago, flowers, heads, sugars, phenolic compounds.

Acknowledgments
The authors are grateful SAIA (Bratislava, Slovakia). Experimental activities were realized in
laboratories Excellent center for the conservation and use of agrobiodiversity at the Faculty of
Agrobiology and Food Resources, Slovak Agricultural University in Nitra.

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Spiritual Human Development
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