Studies were performed to determine the influence of salinity on the antioxidant status of basil plants, var. Sweet Green. The experiments were conducted in a growth chamber under controlled conditions (photoperiod—14/10 h, photosynthetic photon density (PPFD)—250–300 µmol m−2 s−1, temperature—24 ± 1 °C/16 ± 1 °C, humidity—65–70%). The plants were grown on ½ Hoagland’s nutrient solution, with the addition of elevated concentrations of sodium chloride (0, 80, 160 mM). In addition, increased content of macro- and micronutrients in the solution was applied (4/2 Hoagland’s nutrient solution and 0 mM NaCl). The activity of the antioxidant enzyme guaiacol peroxidase, content of malondialdehyde and total polyphenolic compounds, concentration of free proline, and antiradical activity were characterized. The results demonstrate that the salinity of Hoagland’s solution with 160 mM NaCl induced considerable changes concerning enzymatic and non-enzymatic elements of the plant defense and antioxidant systems. Enhancing the concentration of macro- and microelements in the nutrient solution (4/2 of Hoagland and 0 mM NaCl) in terms of biochemical parameters presented a similar trend to the variant with an additional lower concentration of sodium chloride (80 mM).

The study evaluated basil plants’ response (var. Sweet Green) to increased concentrations of sodium chloride (NaCl) and macro- and micronutrients in the medium. The following variants were used: ½ Hoagland nutrient solution containing NaCl (0, 80 and 160 mM) and 4/2 Hoagland solution with 0 mM NaCl. Biometric and physiological parameters were measured 20 days after saline application. The application of 160 mM NaCl in nutrient solution caused the suppression of basil plants’ growth. The height of plants was decreased by 22% and the length of the roots was less by 60%. Control plants had 68% greater leaf area than those grown in the medium with 160 mM NaCl. Compared to the control, basil grown in ½ Hoagland solution with 80 mM NaCl and 4/2 Hoagland solution with 0 mM NaCl had leaf area reduced by 43.4% and 48.2%, respectively. A single plant’s highest fresh weight was found in the control variant (17.78 g) and the lowest in the ½ Hoagland solution with 160 mM NaCl (5.14 g). A negative effect of 160 mM NaCl in solution on the leaf gas exchange of salt-treated plants was found. At the same time, no negative influence of salinity on the content of photosynthetic pigments was found. The addition of NaCl into Hoagland solution did not affect the maximum photochemical efficiency (Fv/Fm) but modified the actual activity of Photosystem II (PSII). Increasing the concentration of macro- and microelements in the nutrient solution (4/2 of Hoagland and 0 mM NaCl) had a significantly lower negative effect on the growth and photosynthetic activity of basil plants.

The aim of the present research was to test the effect of commercial synbiotic (Bio balance (R)) on growth, physiological and immunological parameters in common carp fingerlings (Cyprinus carpio L.) and on plant productivity and physiological parameters in lettuce (Lactuca saliva L.) cultivated in mesocosmos aquaponic system. The current study demonstrated for first time that the application of synbiotic as feed supplementation in extruded pellet for carp in aquaponics recirculation system could be successful. The positive effect of Bio balance (R) on growth rate and feed utilization in carp fingerlings cultivated in aquaponic mesocosmos was observed and average final weight and FCR in fish fed with feed supplemented with Bio balance (R) were higher with 9.8% and 26.1% respectively, compared to the values of these parameters for fingerlings received feed without addition of synbiotic (P <= 0.05). The bactericide and phagocytosis activities and hemoglobin content in blood of carps were higher in fish from the experimental variant (S-1), compared with the values of these parameters found in fingerlings from the control variant (S-0), but the differences were not significant (P >= 0.05). The lettuces from S-1 showed 2.14% higher fresh weight compared to that of lettuces from S-0, but the difference was not significant (P >= 0.05). The better yield in lettuce from experimental variant S-1 where the carp feed was supplemented with synbiotic probably was result from better pH in water and the connected with this better assimilation of nutrients from the salad from S-0 variant. Fingerlings diet supplemented with Bio balance (R) stimulates the physiological proceses in the experimental plants. The positive effect of the synbiotics is reflected by improved leaf gas exchange parameters and nitrate reductase activity in lettuce.

The effect of salt stress on the activity of antioxidative enzymes was studied in leaves and roots of bean plants (Phaseolus vulgaris L.), grown under control (nutrient solution) and salt stress (nutrient solution containing 100 mM NaCl and Na 2 SO 4 ) conditions. In the leaves of salt-stressed plants, ascorbate connected enzymes (APX, MDHAR and DHAR) demonstrated increased activity and at the same time their activity was decreased the in roots. The increase of the enzyme activity was more pronounced under sodium sulfate compared with the chloride treatment in the bean leaves. In saltstressed roots the Na 2 SO 4 application reduced the activity at a higher degree. As a result of the two salt treatments of bean plants the CAT activity were increased in the roots and decreased in the leaves as compared with the control. The observed differences in the enzyme activities show the specific reaction in the different organs of the bean plants as well as the dependence on the kind of the applied salts. Êëþ÷îâè äóìè: àíòèîêèñëèòåëíè åíçèìè, ñîëåâè ñòðåñ, Phaseolus vulgaris L.

Summary. The effects of two salts, NaCl and Na 2 SO 4 , applied at a concentration of 100 mM each in the root medium, оn the antioxidant enzymes (GR, GPX and GST) and glutathione (GSH) homeostasis of hydroponically grown bean plants (Phaseolus vulgaris L.) were studied. An increased GPX activity as well as decreased GSH content in both root and leaf of salt-treated plants were well expressed. The other enzymes studied (GR and GST) responded organ- and salt-specifically. The results obtained showed that both salts provoked oxidative stress responses in the treated bean plants.

The physiological responses of three different bean cultivars (cv. Lody, cv. Gina and cv. Tara) to salt stress were studied under laboratory conditions. The plants were grown in pots as hydroponic cultures in a half-strength Hoagland nutrient solution. The plants were treated for 7 days with NaCl and Na2SO4 (100 mM), starting at the appearance of the first trifoliate leaf unfolded. It was established that the applied dose of both salt types caused stress in the young bean plants, which found expression in the suppression of growth and photosynthesis activity. The bean cultivars showed different reaction to salinity and the type of salt. It was evident that cv. Lody was most sensitive to salt stress. The applied Na2SO4 caused stronger inhibition in all cultivars than those treated with NaCl. The amount of proline in the tissues of the salt-treated plants increased, while the cell water potential was reduced.

The response of three bean cultivars (Phaseolus vulgaris L.) to equimolar NaCl and Na2SO4 salinity at germination and early seedling growth was investigated. Seeds were germinated and grown in Petri plate on filter paper with solution of the respective treatment and incubated at 25 degrees C in a thermostat. Each treatment was replicated three times. The seedlings were harvested and their growth, as well as their germination and respiration rates were measured.All treated cultivars registered decrease in the percentage of germination, seedlings growth and respiration rate. The cultivars were inhibited stronger by Na2SO4 than NaCl treatment.

The effect of salt stress оn the physiological reaction in young bean plants was studied. The plants were grown in pots as hydroponic cultures in half-strength Hoagland nutrient solution under controlled conditions in a climatic room. The plants were treated for 7 days with NaCl and Na2SO4 (concentration 100 mM), starting at the appearance of the fi rst trifoliate leaf unfolded. The salts were added to the nutrient solution. It was established that the equimolar concentrations of both salt types caused stress in the young bean plants, which found expression in the suppression of growth, photosynthesis activity and caused changes in stomata status (conductivity, number and size). The transpiration and the cell water potential in salt-treated plants were reduced. The MDA level in root and shoot, and the proline content was increased.

The effect of salt stress оn some physiological parameters in young bean plants (cv. Lody) was studied under controlled conditions in a climatic room. The plants were grown in pots as hydroponic cultures in half-strength Hoagland nutrient solution. The plants were treated for 7 days with 50 and 100 mM NaCl and Na2SO4 , starting at the appearance of the fi rst trifoliate leaf unfolded. The salts were added to the nutrient solution. It was established that the applied doses of both salt types caused stress on the young bean plants, which found expression in the suppression of growth, photosynthesis activity and the plastid pigment content. The amount of proline in the tissues of the salt-treated plants was increased, while the cell water potential was reduced.