Search

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.

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

Radiation mutagenesis has been used in sustainable agriculture as a tool for increasing plant variability and providing new lines for selection. This necessitates a comparison, by using suitable stress markers, of the newly created lines with some well-established varieties, which are stress tolerant or susceptible. Drought is one of the most frequently encountered stresses with deleterious effects on plant performance and crop yield. Winter wheat seedlings (soil cultures at 3-4th leaf stage) from one mutant line (M181/1338K), one drought-tolerant (Guinness) and one sensitive variety (Farmer) were subjected to severe drought stress by water withholding, followed by recovery. Changes in leaf protein profiles, the amount of Rubisco large subunit (RLS), some specific chloroplast proteins such as Rubisco binding protein (RPB), Rubisco activase (RA), the chaperone subunit clpA/C of clp protease, as well as the activities of exo- and endo- peptidases were analyzed. At the protein level, some differences were found in the drought response of genotypes – stability of RLS and RBP in M181/1338K and Guinness, diminution of RLS and increase in RBP in Farmer. RA presented strong up-regulation at recovery in Guinness but decreased in content under drought in M181/1338K and Farmer. Increase in ClpA/C level was found in all compared varieties under stress. Strong increase in total proteolytic activity was detected under drought only in Farmer. Inhibitory analysis revealed a predominance of cysteine and serine protease types. Aminopeptidase activities remained higher at recovery in M181/1338K and Farmer. Results are discussed in terms of genotype-linked different stress coping strategies.