The change in the biometric and physiological parameters of aster (Callistephus chinensis), helichrysum (Helichrysum bracteatum) and echinacea (Echinaceae purpurea) under conditions of induced water deficit

The global climate models predict changed precipitation patterns with frequent episodes of drought. Scarcity of water is a severe environmental constraint to plant productivity. Plants display a variety of physiological and biochemical responses at cellular and whole-organism levels towards prevailing drought stress. This study included container experiments with three flower crops aster (Callistephus chinensis), helichrysum (Helichrysum bracteatum) and echinacea (Echinaceae purpurea). Drought was simulated by reducing the number of watering’s to field capacity from 25–30 to 85–90 %. Three levels of watering were studied - three times, twice and once a week. The results showed that the cultivation of ornamental plants in containers under reduced watering conditions (twice or once a week) for a period of 3 months led to considerable inhibition of growth and even to plants death. The relative water content and the level of electrolyte leakage vary depending on the weekly number of waterings. The highest values of electrolyte leakage were reported in a single watering for aster -5107.1µS / g, for helichrysum -8314.9 µS / g and for echinacea -3722.8 µS / g. The high rates of conductivity, especially with one-time weekly watering, are evidence of the damage caused by the simulated water stress. This corresponds to the reported low percentages of RWC % and the low values for the height and diameter of the plants. The relative water content in plant tissues decreases depending on the irrigation regime. The lowest values for aster, helichrysum and echinacea were again observed in the variant with a single weekly watering, respectively 15%, 11.5% and 15.8%.

Ecological and biological features of annual ornamental plants under pre-winter sowing in a continental climate

The paper presents the results of a long-term study of biological features of annual ornamental plants species belonging to the ecological group of therophytes included in the bioresource collection USU 44053 and capable of creating a high ornamental effect after pre-winter sowing in the ground. The hydrothermal conditions of the wintering and subsequent vegetation periods are characterized. The accumulation of snow necessary for successful overwintering of seeds is analyzed. Comparative phenospectra of species under different cultivation methods are presented, with an emphasis on achieving the fruiting phase. Examples of naturalization of these species are given, which characterize their high adaptive potential. The most promising species for use in the urbanized environment of the Siberian region are: Amaranthus caudatus L., A. paniculatus L., Brachycome iberidifolia Benth., Calendula officinalis L., Centaurea cyanus L., Clarkia unguiculata Lindl., C. pulchella Pursh., Eschscholzia californica Cham., E. pulchella Cham., Gilia achilleifolia Benth., G. capitata Sims, G. tricolor Benth., Gypsophila elegans M. Bieb., Helichrysum bracteatum (Vent.) Andrews, Iberis umbellata L., Layia elegans Torr. A. Gray, Rudbeckia hirta L., Salpiglossis sinuata Ruiz Pav., Schizanthus pinnatus Ruiz Pav., Vaccaria hispanica (Mill.) Rauschert.

Effects of Helichrysum bracteatum flower extracts on UVB irradiation-induced inflammatory biomarker expression

Background The present study aimed to investigate the anti-inflammatory activity of Helichrysum bracteatum (H. bracteatum) flower extracts in vitro. Methods H. bracteatum flowers were extracted with water, ethanol and 1,3-butylene glycol, and the anti-oxidative activities of the extracts were measured using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The inhibition of the expression of inflammation-related genes, including tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2), was evaluated in vitro using reverse transcription-PCR in ultraviolet B (UVB)-irradiated human epidermal keratinocytes (HEKa cells). To investigate the inhibitory effects of H. bracteatum flower extracts on UVB-induced inflammatory responses in HEKa cells, the production of nitric oxide (NO) and TNF-α was measured using enzyme-linked immunosorbent assays. Results were expressed as the mean ± standard deviation; statistical significance was calculated using the Student’s t-test. Results The DPPH assay results showed that H. bracteatum flower extracts have good anti-oxidative effects and inhibited the expression of inflammation-related genes IL-6, COX-2 and TNF-α. Moreover, the production of NO and TNF-α was inhibited by H. bracteatum flower extracts. Conclusions These findings indicate that H. bracteatum flower extracts have efficacy against UVB-induced inflammation-related gene expression.