Changes of chlorophyll fluorescence parameters and plant performance induced by pre-sowing treatment of Fagopyrum esculentum seeds with cold plasma

Abstract

The effects of cold plasma (CP) are under extensive investigation as an alternative to the traditional pre-sowing seed treatment technologies. Numerous studies provide evidence that seed treatment with CP improves agricultural crop performance. The objective of this study was to evaluate the effects of seed treatment with CP on growth and physiological activity of buckwheat (Fagopyrum esculentum) variety ‘Nojai’ plants. Seeds processed with capacitively coupled plasma device at a pressure of 60 Pa for 5 and 7 minutes (CP5 and CP7 treatments) were sown four days after CP treatment and grown in the field for 14 weeks. At the beginning of flowering growth stage, the chlorophyll a fluorescence measurements were performed by a Plant Efficiency Analyser (PEA) with randomly selected youngest fully expanded leaves. The results showed, that cold plasma treatment had statistically significant effect on several fluorescence parameters of Fagopyrum esculentum. The differences in the efficiency of second photosystem (Fv/Fm) between control and treated groups were statistically significant: this parameter was higher by 10.3 and 11.2 % after CP5 and CP7 treatments, respectively. Electron transport flux per cross section (ETo/CSm) was 2.6 and 3.2 times higher in CP5 and CP7 groups as compared to the control. The increase of electron transport and efficiency of the PSII might be explained by 37 and 39 % increased trapped energy flux per cross section (TRo/CSm) after CP treatment. 10 and 11% higher maximum quantum yield of primary photochemistry (phi(Po)) and 2.2 and 2.6 times higher quantum yield for electron transport (phi(Eo)) was detected for plants growing from CP exposed seeds. Thus, the obtained results indicate strong activation of photosynthetic system induced by seed exposure to CP and these changes were associated with stimulation of growth. [...]