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Several studies have represented data on in vitro clonal multiplication of Physalis peruviana L. using different nutrient media supplemented with diverse growth regulators, but there is still scarce information on the changes in the antioxidant potential of the plants subjected to micropropagation. The present research investigates the effect of various plant growth regula-tors on the antioxidant activity of micropropagated P. peruviana L. The seedling explants of P. peruviana (L.) were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of the studied citokines, 6-benzylaminopurine (BAP), zeatin and thidiazuron (TDZ).The micro-shoots produced normal roots within two weeks of cultivation on half-strength MS medium supplemented with the auxins indole-3-butyric acid (IBA) or indole-3-acetic acid (IAA) at concentrations 0.1 mg L-1 and 0.5 mg L-1, respectively. The most efficient plant rooting was achieved with plants grown on half-strength MS medium with 0.1 mg L-1 IBA (number of shoots per explant 12.1 with a shoot height 5.2 cm) as well as 0.1 mg L-1 IAA (number of shoots per explant 10.4 with a shoot height 7.3 cm) after four weeks of cultivation. The reported micropropagation protocol here is characterized by a rapid proliferation and facilitated rooting of the microshoots. The multiple plants were successfully adapted showing 100% survival rate after two months of ex vitro growth. The changes of en-zyme and non-enzyme antioxidant activity were found to depend on the concentration of the used cytokinins. At the lower concentration of 0.5 mg L-1 of studied cytikinins the antioxidant capacity was characterized by a higher concentration of metabolites with antioxidant poten-tial. The higher cytokinin concentration of 0.1 mg L-1 used in the micropropagation procedure resulted in higher antioxidant enzyme activity. The influence of different growth regulators on the antioxidant potential of micropropagated P. peruviana L. plantlets is discussed.

The research aims to obtain more information on the nitrogen metabolism and nutraceutical properties of two types Lactuca sativa L. var. crispa L. type Batavia cv. 'Maritima' and type Lollo Rosso cv. 'Tuska' and one type Lactuca sativa L. var. capitata L. cv. 'Winter butterhead' under the implementation of different organic fertilizers. In this respect, the main goal of our study is to define a proper macro- and micronutrients source which has the most beneficial effect on yield as well as on various quality parameters of lettuce. The experiment was conducted in an unheated greenhouse in two consecutive seasons (2018/2019 and 2019/2020) under all the requirements for organic production. Four organic fertilizers (Italpollina”, “Arcobaleno”, “Lumbrical” and “EKOprop” were studied. From obtained results, it could be concluded that the impact of fertilizers on lettuce growth and quality has possessed cultivar dependence. The fertilizing with natural fertilizers, so that the nutrients they possess are strictly comprised of animal-based materials (dry bird manure “Italpolina”, mix from bovine, horse and chicken manure “Arkobaleno”) or compost (lumbricompost made by Red Californian worms “Lumbrical”) of the three lettuce cultivars resulted in lower plant FW and yield, compared with NPK fertilizing. Only fertilizing with a mix of different beneficial microorganisms leads to the same plant FW and yield as fertilizing with inorganic fertilizer. Based on the higher plant FW and yield of all three lettuce cultivars the treatment with the fertilizer composed with beneficial microorganisms can be substituted with the treatment with inorganic NPC fertilizer. “EKOprop” fertilizing showed the lowest leaf nitrate concentration which correlated with higher activity of nitrogen assimilating enzyme nitrate reductase.

Among other crop plants legumes are of great significance for agricultural practice since they represent a major source of proteins for human and animal consumption. Through their participation in symbiotic nitrogen fix- ation in a tight relationship with soil bacteria, atmospheric nitrogen is reduced to ammonium which is a more suitable form of N for utilization of nearly all plant species. Symbiotic nitrogen fixation is a natural means for improving soil fertility advantageous over chemical fertilizing which has lower efficiency and greater economic and ecological costs. High soil salin- ity seriously decreases crop yield and productivity. In this review, we exam- ine the current knowledge and understanding of the effect of salinity stress on legumes and symbiotic nitrogen fixation and discuss mechanisms and management strategies for improving crop performance. The potential of using legumes as green manure in order to ameliorate plant productiv- ity in saline environments is discussed. Promising technologies for increas- ing crops nutrient content like the utilization of plant growth-promoting bacteria and the newest research efforts involved in transferring nitrogen- fixing capacity to non-legumes and economically important plant species are outlined.

Salt stress is major abiotic stress problem in arid and semi-arid regions and irrigation areas. Approximately 40% of the world’s cultivated land, and nearly half of the irrigated land is affected by high salt contents. Salt stress affects plant physiology at both whole-plant and cellular levels through osmotic and ionic stress. A secondary effect of salt stress is the increase of reactive oxygen species (ROS), which include singlet oxygen, superoxyde anion radicals, hydroxyl radicals, and hydrogen peroxide. The effect of the source of nitrogen nutrition (nitrogen fixation or nitrate assimilation) on the response of antioxidant system of soybean plants subjected to salt stress was studied. Activity of some stress defense enzymes (catalase, peroxidase, and SOD), GSH and GSSG in nitrogen-fed and nitrogen fixing plants was measured. Catalase and peroxidase activity was higher in the leaves of nitrogen fixing plants compared to nitrate-fed. Therefore, symbioses showed different tolerance level under salinity condition which was essentially correlated with symbiotic performance at nonstressful conditions.