Seed treatment with cold plasma and electromagnetic field: effects on germination, plant growth, and the amount of flavonoids in the leaves of Red clover (Trifolium pratense)

Red clover (Trifolium pratense L) is used as a dietary supplement for alleviation of menopausal symptoms or treatment of prostatic diseases. Commercial extracts of red clover contain estrogenic isoflavones, with formononetin (F) and biochanin A (BA) found in the largest amounts. The aim of study was to estimate the effects of pre-sowing seed treatment, using radio-frequency electromagnetic field (EMF, 10 and 15 min) and cold plasma (CP, 5 and 7 min), on germination, growth and biochemical traits of seedlings of two cultivars of red clover – ‘Vyčiai’ and ‘Sadūnai’. The impact of treatments on morphological traits, and concentration of isoflavones F and BA (detected by HPLC analysis) was estimated in leaves of plants grown in the experimental plots for 5 months. The germination tests in vitro revealed that CP treatments increased germination rate, and this effect was more pronounced for ‘Vyčiai’ (germination rate increased up to 24%). EMF treatments did not affect germination indices, only EMF (15 min) reduced germination percentage of ‘Sadūnai’ by 12%. The induced changes in plant morphometric parameters were dependent on cultivar of red clover. The average number of stems per one plant for ‘Vyčiai’ was increased from 26 to 40% in all treated groups, in comparison to control, but the number of stems of ‘Sadūnai’ cultivar was not affected by seed treatments. Dry weight of ‘Vyčiai’ plants in CP (5 min) and EMF (15 min) groups was by 37 and 43% larger, dry weight of stems was by 36 and 42%, dry weight of leaves – by 49 and 34% larger in comparison to control, respectively. Positive morphometric changes induced by seed treatments in morphometric traits of ‘Sadūnai’ were less pronounced in comparison to ‘Vyčiai’ cultivar. [...]Biochemijos katedraGamtos mokslų fakultetasLietuvos agrarinių ir miškų mokslų centro filialas Žemdirbystės institutasVilniaus universitetasVytauto Didžiojo universiteta