Cold plasma treatment as seed dormancy breaking agent

The aim of this study was to evaluate the dependence of atmospheric cold plasma (CP) irradiation effects on the duration of treatment and time interval passed between treatment and sowing. We estimated changes induced in radish (Raphanus sativus) germination and content of the main phytohormones controlling germination – abscisic acid (ABA) and gibberelins (GA7 and GA3) in dry seeds. Radish seeds were treated for different durations (1, 3, 5, 7 and 10 min) with a scalable dielectric barrier discharge (DBD) device. The discharge voltage, current and power density were 7.0 kV, 0.2 A and 3.1 W/cm2, respectively. Germination tests in vitro were performed 0, 1, 4, 8 days (CP 5 min) and 14 days (CP 1, 2, 3, 5, 7, 10 min) after treatment, and at the same time methanol extracts of dry seed homogenates were prepared for phytohormone HPLC analysis. Indices of germination dynamics – the final germination percentage Vi (%) and the median germination time Me (h), were determined using Richards plots. Morphometric seedling analysis was performed 4 days after sowing. CP treatment strongly stimulated germination: Vi increased from 18 to 30%; Me decreased from 15 to 29% in all CP treated seed groups in comparison to control. Increase of irradiation time above 5 min did not lead to stronger positive effects on germination as it was achieved by 5 min irradiation. Both effects on germination and morphometric parameters of seedlings were stronger when time interval between seed treatment and sowing was increased from 0 or 1 day to 4 days. In all groups of CP-treated seeds ABA content was strongly reduced while GA7 content was increased. Strong negative correlation (R2=0,934) was obtained between Vi and ABA content, and between Vi and ABA/(GA7+GA3) (R2=0,936). Positive polynomial correlation between Me and GA7+GA3 was characterized by R2=0,843. [...]Biochemijos katedraBotanikos sodasGamtos mokslų fakultetasVytauto Didžiojo universiteta

Effects of seed treatment with cold plasma and electromagnetic field on buckwheat (Fagopyrum esculentum) seeds germination, seedlings growth and antioxidant capacity

Buckwheat (Fagopyrum esculentum) is a popular food component in Lithuania characterized by high nutritional value due to the presence of potential antioxidants, such as rutin, other phenolic substances, and tocopherols. We studied the effects of pre-sowing seed treatment with radio-frequency electromagnetic field (EMF, 5-15 min) and cold plasma (CP, 2-7 min), on germination (in vitro and in substrate), seedling growth and radical scavenging activity of two buckwheat cultivars – ‘Nojai’ and ‘Vokiai’ (seeds were kindly provided by dr. D. Romanovska from Voke branch of Lithuanian Research centre for Agriculture and Forestry). Final germination percentage indicating seed viability in control and all treated groups in vitro and in substrate was about 100%. Germination tests in vitro revealed that CP treatments slightly increased germination rate only in “Nojai”, (T50 decreased by 7% in CP 7 min group), EMF treatments had no effect on germination rate in vitro. CP and EMF effects on germination in substrate were different from their effects in vitro: both CP and EMF decreased germination rate of ‘Nojai’ (by 14 and 15% CP 2 min and EMF 15 min, respectively) while germination of ‘Vokiai’ was not affected. Despite suppressing effects on germination rates in substrate, CP and EMF treatments induced positive changes in morphometric parameters of seedlings grown for 6 weeks in the climatic chamber under controlled conditions. For both cultivars height and wet weight of seedlings, the average number of leaves per plant and the number of flowering plants in experimental groups grown from treated seeds was larger (up to 15, 33, 33 and 34%, respectively) in comparison to the corresponding control, while roots were longer only in ‘Vokiai’ cultivar plants from treated seeds groups (up to 14 %) compared to control..[...]Biochemijos katedraBotanikos sodasGamtos mokslų fakultetasVytauto Didžiojo universiteta

Buckwheat seed treatment with electromagnetic field and cold plasma accelerates seedling growth and induces changes in radical scavenging activity of leaf extracts

Buckwheat, traditional crop cultivated in many countries, is a rich source of vitamins, essential amino acids and phenolic compounds, which are responsible for many of the health benefits and antioxidant properties of this plant. We aimed to investigate the effects of pre-sowing seed treatment with radio-frequency electromagnetic field (EMF, 5-15 min) and cold plasma (CP, 2-7 min), on germination, seedling growth and radical scavenging activity of two buckwheat cultivars – ‘Nojai’ and ‘Vokiai’ (seeds were kindly provided by dr. D. Romanovska from Voke branch of Lithuanian Research centre for Agriculture and Forestry). Final germination percentage indicating seed viability in control and all treated groups in vitro and in substrate was about 100%. Germination tests in vitro only negligible effects of treatments on germination kinetics of both cultivars. CP and EMF effects on germination in substrate were different from their effects in vitro: both CP and EMF decreased germination rate of ‘Nojai’ (by 14 and 15% CP 2 min and EMF 15 min, respectively) while germination of ‘Vokiai’ was not affected. Despite suppressing effects on germination rates in substrate, CP and EMF treatments induced positive changes in morphometric parameters of seedlings grown for 6 weeks in the climatic chamber under controlled conditions. For both cultivars height and wet weight of seedlings, the average number of leaves per plant and the number of flowering plants in experimental groups grown from treated seeds was larger (up to 15, 33, 33 and 34%, respectively) in comparison to the corresponding control, while roots were longer only in ‘Vokiai’ cultivar plants from treated seeds groups (up to 14 %) compared to the control. [...]Biochemijos katedraBotanikos sodasGamtos mokslų fakultetasVytauto Didžiojo universiteta