ABSTRACT
The aim of this work was to assess the regeneration capacity of Amelanchier alnifolia var. cusickii and Lonicera kamtschatica cv. 'Jugana' from different types of explants under various hormonal treatments. The whole leaves, petioles, and internodal segments of in vitro plants were examined as explants. Several plant growth regulators (cytokinins and auxins) were evaluated for their ability to induce adventitious regeneration. Direct and indirect organogenesis was achieved under certain culture conditions in both species. The frequency of shoot regeneration was strongly dependent on concentrations of plant growth regulators in the induction media (L.kamtschatica 'Jugana') or concentrations of plant growth regulators in the induction media and type of explant (A. alnifolia var. cusickii). Results showed that leaves were not suitable explants for A. alnifolia var. cusickii. Both species were able to regenerate shoots from internodal segments and petioles. The highest induction of shoots was obtained on Murashige and Skoog (MS) medium enriched with 2 mg/L thidiazuron (TDZ) and 0.5 mg/L indole-3-butyric acid (IBA) for Amelanchier alnifolia and with 1 mg/L TDZ and 0.2 mg/L indole-3-acetic acid (IAA) for L. kamtschatica 'Jugana'. Obtained adventitious shoots were further proliferated in order to investigate their multiplication capacity. The multiplication of shoots was successful in all cultivars, with the best results reported in A. alnifolia var. cusickii (7.07 shoots/explant on average).
ABSTRACT
Grain amaranth is known as an alternative crop with exclusive nutritional value and health benefits. The purpose of this study was to investigate the effect of gamma irradiation on quantitative and qualitative amaranth seed traits, including 1000-seed weight, amino acids, fatty acids content, oil, and squalene yield. Two Slovak mutant varieties "Pribina" (A. cruentus) and "Zobor" (A.hypochondriacus x A. hybridus) were evaluated and compared to nonirradiated controls Ficha (A. cruentus L.) and K-433 (A. hypochondriacus x A. hybridus) and commercial varieties, Aztec (A. cruentus L.), Plainsman and Koniz (A. hypochondriacus x A. hybridus). Mutant varieties, "Pribina" and "Zobor", showed superior 1000-seed weight performance compared to all investigated amaranth samples. The change in quantitative seed trait was accompanied by significantly higher oil and squalene content compared to commercial varieties. Moreover, significantly higher content of essential linoleic acid was detected in mutant variety "Zobor". The present findings suggest that seeds of irradiation-derived varieties have high nutritional potential and can be used as a supplementary crop in the human diet.
ABSTRACT
Berry fruit species are, in many countries, considered biologically and economically valuable and important species of small fruits. The aim of this work was to examine the influence of either decreased or increased mesos concentrations (MgSO4, CaCl2, and KH2PO4) on shoot multiplication of five cultivars of three small fruit species (Amelanchier alnifolia var. cusickii, Rubus fruticosus 'Black Satin' and 'Loch Ness', and Vaccinium corymbosum 'Brigitta Blue' and 'Toro'). Mesos nutrients were manipulated from half to four times their base concentration. The results indicate that mesos manipulation significantly influences the number and length of shoots in most of the studied cultivars. The greatest multiplication rate for A. alnifolia was achieved with tripled mesos, whereas 'Black Satin' and 'Loch Ness' reacted positively to a lower (1-2x) concentration of mesos. Decreasing the concentration of mesos to half led to worse quality in both blackberry and Saskatoon shoots. 'Brigitta Blue' was more sensitive to greater mesos concentrations compared to 'Toro'. Optimizing the mineral nutrition of plants cultivated in vitro enhances their multiplication rate and contributes to a higher production of good quality plantlets.
ABSTRACT
A collection of 68 isolates of Salmonella enterica serovar Kentucky collected during the period 2003-2004 from humans in two geographical regions in the Slovak Republic was studied. The original isolate of this serovar was associated with travel to Egypt, and the emergence of other isolates was due to the nosocomial spread of this strain in two hospitals. Antimicrobial susceptibility testing, class I integrons content, pulsed-field gel electrophoresis (PFGE) analysis and plasmid DNA profiles were performed on all isolates. A high proportion (89.7%) of the isolates was multidrug-resistant, while 67 strains expressed resistance against ciprofloxacin. By sequence analysis of randomly selected strains, the point mutations in quinolone resistance-determining region of the DNA gyrase were found. The S. Kentucky isolates investigated were determined to be clonally related by PFGE as well as plasmid DNA analysis.
