Effects of salt stress on the photosynthetic physiology and mineral ion absorption and distribution in white willow (Salix alba L.)

Objective The purpose of this study was to explore the adaptive mechanism underlying the photosynthetic characteristics and the ion absorption and distribution of white willow (Salix alba L.) in a salt stress environment in cutting seedlings. The results lay a foundation for further understanding the distribution of sodium chloride and its effect on the photosynthetic system. Method A salt stress environment was simulated in a hydroponics system with different NaCl concentrations in one-year-old Salix alba L.branches as the test materials. Their growth, ion absorption, transport and distribution in the roots and leaves, and the changes in the photosynthetic fluorescence parameters were studied after 20 days under hydroponics. Results The results show that The germination and elongation of roots are promoted in the presence of 171mM NaCl, but root growth is comprehensively inhibited under increasing salt stress. Under salt stress, Na+ accumulates significantly in the roots and leaves, and the Na+ content and the Na+/K+ and Na+/Ca2+ root ratios are significantly greater than those in the leaves. When the NaCl concentration is ≤ 342mM, Salix alba can maintain relatively stable K+ and Ca2+ contents in its leaves by improving the selective absorption and accumulation of K+ and Ca2+ and adjusting the transport capacity of mineral ions to aboveground parts, while K+ and Ca2+ levels are clearly decreased under high salt stress. With increasing salt concentrations, the net photosynthetic rate (Pn), transpiration rate (E) and stomatal conductance (gs) of leaves decrease gradually overall, and the intercellular CO2 concentration (Ci) first decreases and then increases. When the NaCl concentration is < 342mM, the decrease in leaf Pn is primarily restricted by the stomata. When the NaCl concentration is > 342mM, the decrease in the Pn is largely inhibited by non-stomatal factors. Due to the salt stress environment, the OJIP curve (Rapid chlorophyll fluorescence) of Salix alba turns into an OKJIP curve. When the NaCl concentration is > 171mM, the fluorescence values of points I and P decrease significantly, which is accompanied by a clear inflection point (K). The quantum yield and energy distribution ratio of the PSⅡ reaction center change significantly (φPo, Ψo and φEo show an overall downward trend while φDo is promoted). The performance index and driving force (PIABS, PICSm and DFCSm) decrease significantly when the NaCl concentration is > 171mM, indicating that salt stress causes a partial inactivation of the PSII reaction center, and the functions of the donor side and the recipient side are damaged. Conclusion The above results indicate that Salix alba can respond to salt stress by intercepting Na+ in the roots, improving the selective absorption of K+ and Ca2+ and the transport capacity to the above ground parts of the plant, and increasing φDo, thus shows an ability to self-regulate and adapt.

Traditional ethnoveterinary knowledge of indigestion or diarrhoea treatments in cattle on the Bilogora hills in Croatia

Traditional knowledge of plants and their preparations used for the treatment of animal diseases was passed down orally from generation to generation, so there are no written records or they are very rare. This study is based on the first documentation of ethnoveterinary knowledge for indigestion or diarrhoea treatment in cattle on the Bilogora hills in northwestern Croatia. Data collection was conducted from 2008 until 2018, in eighteen villages of four municipalities in the Koprivni?ko-križeva?ka county, Croatia. Plant specimens were well known, in addition they were confirmed and identified by the skilled botanist. Nine plant species: flax (Linum usitatissimum L.), chamomile (Matricaria recutita L.), hazelwort (Asarum europaeum L.), broad-leaved dock (Rumex obtusifolius L.), sweet chestnut (Castanea sativa Mill.), common oak (Quercus robur L.), white willow (Salix alba L.), common mallow (Malva sylvestris L.), yarrow (Achillea millefolium L.) from 7 botanical families were documented. Decoction and herbal tea were the most common preparation methods. The most often used plants to treat mild diarrhea in cattle were chamomile and broad-leaved dock, and for hard, watery diarrhoea bark of sweet chestnut and sessile oak. The most often used plants to treat indigestion in cattle were hazelwort, chamomille, and flaxseed. Farmers used mostly leaves (about 57%), flowers and stems (more than 25%), bark (about 13%), branches, and seeds (5%) for herbal preparations. Thus the aim of the present study is to document that ethnoveterinary tradition for the next generations. Keywords: Cattle; Diarrhoea; Ethnoveterinary; Indigestion

Effect of wastewater sludge treatment on early growth and physiological responses of willow (Salix spp.) and poplar (Populus spp.) pot-grown plants

Combining biomass production from fast-growing woody species with wastewater treatment is an attractive concept from the economic, energy and environmental points of view. A pilot experiment on study-ing the effect of wastewater treatment on the early growth and initial physiological responses of willow and poplar plants was carried out in greenhouse conditions. The survival, height growth, net photosyn-thesis, stomatal conductance and transpiration of two hybrid clones of black poplar (Populus x euroameri-cana (Dode) Guinier) (I-214 and I-45/51) and white willow (S. alba L.) pot-grown plants treated with different doses of agrochemically characterised wastewater sludge were studied during the establishment year. The height growth and number of resprouted willow shoots were also measured during the second year after cutting, at the end of the vegetation season. While the early growth height of poplar clones was markedly affected by the clone origin and wastewater sludge treatment, the latter did not considerably influence the height of the willow plants either during the establishment and the following year, but essentially increased the number of resprouted shoots during the second vegetation season. The rate of CO2 assimilation of willow plants was significantly influenced by the wastewater sludge treatment, with plants grown at the higher doses displaying higher photosynthetic performance. The application of wastewater sludge had no essential impact on the values of the physiological parameters of the poplar plants, but particular responses were found among the clones.

Dose-dependent effects of isotopic exchange of tritium in the process of willow vegetation

The paper is devoted to the study of the kinetics of tritium redistribution between living and inanimate matter of white willow in the “greenhouse” experiments. It was shown that the concentration of tritium in the aquatic environment significantly affects the kinetic parameters of its assimilation in the organic and inorganic matter of the organism of the white willow (Salix alba L.). The kinetics of the influx of tritium from the aqueous nutrient into the intracellular juice, the organic phase of plants, and transpiration fumes, depending on the concentration of the superheavy hydrogen isotope, are described. Dose-dependent effects were identified, accompanied by fractionation of hydrogen isotopes in all components of the biosystem - the aquatic food environment, intracellular juice, transpiration fumes, and in the organic phase. It was found that with an increase of the initial specific activity of aqueous feeding solution (by 8.6 times): the rate of tritium removal from it and from intracellular juice increases (by 14.8 and 15.6 times, respectively), the degree of assimilation of this isotope into intracellular juice decreases (by 41.3 times), and its the part that enters the organic phase of wood (1.3 times) decreases the relative proportion of tritium in transpiration water (5.7 times). The existence of physiological barriers that sharply and significantly limit the assimilation of tritium into the components of the willow has been proved. Thus, the value of the barrier during the migration of this isotope of hydrogen into the intracellular juice reaches 15 % and only 18 - 25 % of tritium gets from the external water into the organic phase.

Smoke-Water Enhances Germination and Seedling Growth of Four Horticultural Crops

The impact of plant-derived smoke as a promoter of seed germination in many crops is well documented. However, very little is known about (1) the appropriate plant species for smoke-water preparation, (2) the effect of smoke-water on the germination and the post-germination parameters in non-fire-prone environments, and (3) the relative importance of dark and light conditions and their possible effects. To fill these gaps in knowledge, we conducted field experiments to evaluate the effect of smoke-water produced from five plant species—white willow, sage, rice straw, rosemary, and lemon eucalyptus—on the germination and seedling growth of cucumber, tomato, scotch marigold, and gladiolus. The seeds and cormels were soaked in smoke-water under light or dark conditions. The results revealed that the smoke-water treatments derived from white willow and lemon eucalyptus enhanced germination, post-germination parameters, and macro element content whilst also contributing to dormancy-breaking. In addition, these smoke-water treatments significantly reduced abscisic acid content and increased α-amylase activity under light conditions; however, the stimulating effects were absent under dark conditions. In conclusion, we provide new evidence that germination and seedling growth in non-fire-prone environments can be enhanced by plant-derived smoke, and that stimulating impacts depend on the plant species used to prepare the smoke-water.