Modelling water deficit conditions for investigation of its influence on tomato plants

Aim. To model water deficit conditions using polyethylene glycol (PEG) 6000, determine effective concentrations and treatment time of PEG for investigation of the influence of water deficit on the seed germination and morpho-physiological parameters of tomato cv. Money Maker plants. Methods. The methods of sterilization, in vitro cultivation, micropropagation of plant material and statistical analysis were used in this work. PEG 6000 at concentrations of 2 %, 4 %, 6 %, 8 %, 10 % and 12 % was added into MST medium, and its influence on morphophysiological parameters of tomato seedlings was studied in vitro. Results. Morphophysiological parameters in the presence of 2 % PEG 6000 were not statistically different from that in control. However, at concentrations 4–8 %, seed germination frequency decreased by 39.32–67.27 %, shoot length by 29.77–55.1 %, and root length by 44.6–72.89 %. In the presence of 10 % and 12 % PEG 6000, seed germination frequency, shoot length, and root length were reduced by 93.79–100 %. Conclusions. It was established that the critical concentration of PEG 6000 is 8 %, as it caused the changes in the morphometric parameters of tomato seedlings without a significant loss in viability. Therefore, this concentration of PEG 6000 is recommended for modeling water deficit (drought) conditions to study this type of stress on tomato cv. Money Maker plants.