Secondary salinization caused by climate change is a growing global problem. Searching for plants that can survive in areas with high salt content and even have decorative value was the focus of our research. Thirty plants of Limonium gmelinii subsp. hungaricum were planted in clear river sand; another thirty plants were planted in Pindstrup, a growing substrate enriched with 40% clay. With the latter, we modeled the natural soil. In addition to the control tap-water treatment, plants received 50, 125, 250, 375, and 500 mM NaCl solution irrigation twice a week. The leaf sizes of plants planted in sand decreased proportionally with the increasing NaCl concentration, and their dry matter content increased. In the clay-containing medium, leaf sizes increased, even at a concentration of 375 mM, although the dry matter content increased only at high concentrations. Carotene content in both media became higher, due to the higher NaCl concentrations, while proline content in the plants grown in sandy media increased, even with the 125 mM concentration. With our present experiment we proved the salt tolerance of the taxon, and even the soil’s great importance in supporting the plant’s salt tolerance.

Biostimulants and other plant growth promoters can provide an effective solution to the challenge of urbanisation and climate change. Viburnum opulus ‘Roseum’ is a globally popular deciduous shrub species that can be made more resistant to urban influences by using natural growth-promoting substances. In our study, we investigated the effects of growth promoters Kelpak^®, Bistep and Yeald Plus on the species, both histologically and physiologically (proline stress hormone measurement). Our measurements were complemented using the analysis of rhizosphere alkaline phosphatase, β-glucosidase and β-glucosaminidase enzymes, to obtain a more complete picture of the combined effect of biostimulants and species. We found that the Bistep biostimulant had an outstanding effect on the leaf tissue culture results of the variety. The transpiration and evapotranspiration findings also confirmed the efficacy of biostimulants. In the case of POD activity and rhizosphere enzyme measurements, Bistep and Yeald Plus obtained statistically higher values than the control group. Kelpak produced better results than the control group in several measurements (alkaline phosphatase levels; evapotranspiration results), but in other cases it resulted in lower values than the control treatment. The use of Bistep and Yeald Plus can greatly assist growers in the cultivation of V. opulus ‘Roseum’ in an urban environment.

Ornamental horticulture and breeding, as well as urban landscape architecture, are facing increasing challenges driven by an intensely changing climate and urbanisation. The expansion of cities should be combined with an overall growth of green spaces, where ornamental plant species and cultivars will have to withstand a diverse range of environmental conditions, whereby they are often exposed to multiple stress factors. One of the most widely used ornamental shrub species Weigela florida ‘Eva Rathke’ was treated with the growth promoters Bistep with humic and fulvic acid, Kelpak^® seaweed extract, and Yeald Plus with a high zinc content to test their applicability in a plant nursery. Bistep decreased the physiological parameters (the transpiration rate by 60%, the evapotranspiration rate by 56.5%, and the proline stress enzyme content level by 82.2%), indicating the stress level of the treated plants. The activity of β-glucosidase decreased with all growth-promoting treatments (11.5% for Kelpak and 9.5% for Yeald Plus), as did β-glucosaminidase (22.1% for Kelpak and 9.8% for Yeald Plus), but Bistep treatment reduced the activity of the enzymes less (9.9% for β-glucosidase and 3.3% for β-glucosaminidase). The measured alkaline phosphatase enzyme activity increased with treatment (by 10.7% for Kelpak, 11.7% for Yeald Plus, and 12.63% for Bistep). Based on the results, it was concluded that Bistep and Yeald Plus may be suitable for use in the studied variety, whereas Kelpak^® may not be suggested in plant nurseries for growing W. florida ‘Eva Rathke’ plants.

ISHS VII International Symposium on In Vitro Culture and Horticultural Breeding GROWING SPATHIPHYLLUM IN VITRO: EVALUATION OF SOME COMBINATIONS OF CARBOHYDRATE SOURCES AND MINERALS IN THE MEDIA REGARDING PEROXIDASE ENZYME ACTIVITY AND CHLOROPHYLL CONTENT

Potentially toxic element (PTE) contamination of urban soils poses long-term ecological and public health risks. Ornamental vegetation is increasingly discussed within green-infrastructure-based risk management. We screened and synthesised 167 field studies (>120 ornamental and horticultural plant species) to characterise the scope, reporting structure and design features of the available phytoremediation-related evidence. Studies assessed a mean of 3.21 elements (SD = 1.37); Pb, Cd and Zn were most frequently investigated (67%), whereas Ni, Cr and B occurred in <10%. Reported element richness differed by setting, averaging 3.8 ± 1.5 in wastewater-affected sites versus 2.6 ± 1.1 in urban parks. Using a study-by-element presence/absence matrix, co-reporting patterns separated three recurrent co-reporting profiles. The first three PCs explained 64.5% of variance (PC1: Pb–Zn–B; PC2: Cu–Ni; PC3: Cd–Cr). Accumulation was reported most often (56.8%), while stabilisation (17.9%) and translocation (25.3%) were less commonly addressed. For public space applications, accumulation-focused plantings require a defined maintenance pathway (pruning/harvest, biomass removal, and safe handling or disposal) to avoid recirculation of metal-bearing material within the urban environment. Sampling focused on aboveground tissues (73.4%) more than roots (28.9%). In multiple regression, environmental type was associated with element richness (Adj. R² = 0.08, p = 0.001). Here, richness is treated as an index of reporting breadth. Overall, the dominant quantitative signals reflect context-dependent reporting and study design patterns. They do not represent harmonised, concentration-based remediation outcomes. These patterns provide an evidence map to support context-aware interpretation and future study standardisation.

A special organ formation appearing on the inflorescences of Spathiphyllum cultivars, which has not been described so far in the literature was studied in vivo and in vitro. Histological examination revealed that they are not callus, but bud-like formulas or dwarf shoots growing in groups, which contain highly differentiated tissues, have a shoot axis, meristematic regions, and leaf primordia. These bud clusters have been shown to be propagable in vitro on both solid and liquid media, for which benzyladenine and thidiazuron cytokinins may be recommended. The process of shoot regeneration from these bud clusters was also investigated, which can be accelerated by inhibitors of gibberellin biosynthesis. This study presents a propagation method which is based on organogenesis, thus providing high genetic stability, while incorporating the advantages of liquid culture, allowing the further development of a simplified large-scale bioreactor propagation system for Spathiphyllum species.