Allelopathic influence of medicinal plant Filipendula vulgaris Moench on germination process

The allelopathic potential of medicinal plant Filipendula vulgaris Moench, originated from two natural habitats: calcareous grasslands and humid meadows, was investigated using radish ( Raphanus sativus L. var. radicula Pers.) as a model plant. Suppression influence of aqueous extracts at concentrations: 1%, 5%, 10%, obtained separately from under and aboveground parts of the species, was studied testing germination capacity, biomass and biometry of seedling, and electrolyte leakage. Additionally, two cultivars of the radish were used to test the sensitivity of frequently used plant in the laboratory tests. This study revealed the inhibiting effect of high concentration aqueous extracts from F. vulgaris organs on the germination of radish. It was significant for seed vigour index, speed emergence, germination stress tolerance index, and mean germination time. However, the stimulating effect of 1% of aqueous extracts from dropwort roots and shoots on the germination indexes was documented. Similarly, low concentration extracts had a positive effect on seedling elongation which was visible in biometric analyses and inhibition percentage index but it was not so obvious in the biomass analyses. In general, the aboveground extracts from dropwort grown on calcareous grassland demonstrated higher allelopathic potential than extracts from underground parts and meadow habitat. We used underground and aboveground parts of originated from two natural habitats: humid meadow and grassland to examine the potential of allelopathy and the influence of habitat on production of allelopathic compounds. The germination capacity of seeds was tested by determining the germination indexes, the biometric analysis of seedlings was performed, the value of fresh and dry mass was determined and the percentage of destabilisation of cell membranes was measured. In the experiment two cultivars of radish were used to test the sensitivity of the model plant.


Introduction
Medicinal plants have a long history as a source of potential therapeutic agents, that have been incorporated into modern medicine (e.g. Kamboj, 2000;Tapsell et al., 2006;Verma and Singh, 2008;Atanasov et al., 2015). It is estimated that almost 53,000 flowering plant species are considered medicinal plants (Wakdidar, 2004). They are used mainly due to their natural compounds with biological activity that have a positive effect on maintaining human health. Additionally, secondary metabolites in medicinal plants have been reported as potent growth inhibitory agents indicating that such plants serve as a storehouse for allelopathic compounds (Batish et al., 2006). In the last decade, there is a growing interest to estimate the allelopathic potential of medicinal plants (e.g. Fujii et al., 2003;Amini et al., 2014;Skrzypek et al., 2016;Puła et al., 2020). Behind the researches of allelopathic activity is the purpose of better practice in the cultivation of medicinal plants as well as a future prospect in controlling major crop weeds for sustainable agricultural production (Islam et al., 2018). Increasing consumer awareness of herbicide residues in production practices leads to increased demands for organic products or safer foods (McErlich and Boydston, 2013;Tal, 2018).
Possibility of using plants compounds as natural pesticide promote sustainable agriculture and address audience concerns on the effects of pesticides on the environment and human health (Kropff and Walter, 2000;Dayan et al., 2009). There are suggestions that most allelopathic compounds will be biodegradable and also less polluting than traditional pesticides owing to their shorter half-lives (Daizy et al., 1995).
The aim of the study was to determine the allelopathic influence of aqueous extracts from Filipendula vulgaris on germination process and early growth on model plant Raphanus sativus L. var. radicula Pers. We used separately underground and aboveground parts of dropwort originated from two natural habitats: humid meadow and calcareous grassland to examine the potential of allelopathy and the influence of habitat on production of allelopathic compounds. The germination capacity of seeds was tested by determining the germination indexes, the biometric analysis of seedlings was performed, the value of fresh and dry mass was determined and the percentage of destabilisation of cell membranes was measured. In the experiment two cultivars of radish were used to test the sensitivity of the model plant.

Materials and Methods
Plant material Filipendula vulgaris specimens were collected from two natural habitats in southern Poland: humid meadows and calcareous grasslands in July 2019 ( Figure 1). The humid meadows from the alliance Molinion caeruleae, Molinio-Arrhenatheretea class, were situated on the low flood terrace of the Vistula river where the limestone monadnocks (Jurassic-Cretaceous) and tectonic depressions of the Brama Krakowska gate occur (50°01'48.8"N 19°52'26.7"E,. Histic Aerosol is reported as the soil unit for the place where the meadows occurred (Skiba et al., 2010). The calcareous grasslands, represented Thalictro-Salvietum association from Festuco-Brometea class, were located in the Miechów Upland (50°18'59.1"N 20°04'14.3"E, Małopolska Upland). Rendzic and calcareous leptosols are the soil units that prevailed in the area.

Figure 1. Filipendula vulgaris Moench (dropwort) collected from southern Poland
A -before flowering with a rosette of leaves, rhizomes, and tubers, B -inflorescence, C -specimens in meadow habitat (Photo M. Fecowicz) Fresh material of the species was selected in the laboratory to eliminate defective parts (e.g. damaged, infected leaves, roots). Then the plants were separated into underground parts (roots, tubers, rhizomes) and aboveground parts (shoots, leaves). In the text, the term "roots" is used for underground parts and "shoots" for aboveground parts of the species. The plant material was dried at the temperature of 25 °C, in the dark for 3 weeks in a dryer (Wamed SUP-100, Poland). The dry plant material of F. vulgaris was stored in the paper bags, in the dark, in a desiccator to avoid microbiological destruction of allelopathic compounds present in it.
Radish Raphanus sativus L. var. radicula Pers was selected for the study as a model organism due to the short life cycle and low environmental requirements for germination. Two commonly cultivars of radish: 'Rowa' and 'Krakowianka' were used in the experiment. Both cultivars require sunny areas, rich and permeable soil with low nitrogen content. They differ in the length of the growing season: 'Rowa': 28-32 days, 'Krakowianka': 33-37 days (Kupczak, 2011). The seeds of radish cultivars were purchased from POLAN Sp.z.o.o. Breeding and Seed Horticulture in Kraków (Poland).

Preparation of aqueous extract solutions
Dry plant material was ground separately for under and aboveground parts of dropwort in a mill (Braun, 4 045 type, Germany) and used to prepare the aqueous extracts of various concentrations: 1%, 5%, and 10%. Each extract, depending on the concentration, was flooded with a suitable amount of distilled water (e.g. 5% = 5 g plant material + 95 ml distilled water, 10% = 10 g plant material + 90 ml distilled water) and left for 24 hours, at 25°C temperature, in the dark to extract the compounds. The extracts obtained were filtered through a filter paper on a Büchner funnel by Whatman (Grade 1: 11 μm -medium flow filter paper) filter paper, using a vacuum pump (PL2/3, Al-Conbest, USA), and then stored in a refrigerator for the duration of the experiment.

Seed germination conditions
Radish seeds were sterilised in 1% sodium hypochlorite for 10 min, then rinsed with distilled water (3x). In the experiment, seeds were put on the sterile Petri dishes (25 seeds per dish) with 3 layers of filter paper (Whatman, Grade 1: 11 μm -medium flow filter paper) soaked with 5 ml the aqueous extract of dropwort: separately with different concentrations from under and aboveground parts. Then seeds on dishes were placed in a growth chamber (Angelantoni Industrie, Italy) at 25 °C / 20°C, photoperiod 200 μmol·m -2 ·s -1 (12h day / 12h night), and relative air humidity (RH) 80-90%. The control group was radish seeds treated with distilled water in the same volumes as extract watered seeds. During the experiment, the number of germinated seeds was checked every 24 h. Those that had a hypocotyl at least 2 mm in length were considered germinated. After 7 days, the effect of F. vulgaris aqueous extracts on germination and early growth of radish was measured.

Seedlings elongation
The length of roots and hypocotyls, as well as whole seedlings, was measured using a caliper (Topex 31C615, Poland), with an accuracy of 1 mm. Besides, the seedling length was expressed as a percentage of control by using an inhibition percentage (IP) index: IP = [1 -(LE/LC)] × 100 where: IP -growth inhibition index (%), LE -plant length (cm) treated with aqueous extract, LCplant length (cm) from the control.

Inhibition percentage (IP) of growth (as control %) -a minus (-) value indicates growth stimulation, and a plus (+) value indicates growth inhibition.
Fresh and dry masses, water content Fresh mass (g) of single seedlings was weighted (Ohaus Adventurer Pro, USA). Dry mass of seedlings was determined after 48 h of drying the fresh material in a dryer (Wamed SUP-100, Poland) at temperature 105 °C. Additionally, the percentage of dry mass and total water content were determined.
Dry mass (%) = (dry mass / fresh mass) × 100 H2O (%) = [(fresh mass -dry mass) / fresh mass] × 100 Electrolyte leakage The percentage of destabilisation of cell membranes of radish seedlings was determined by slightly modifying the method described in the study of Możdżeń et al. (2020). A single radish seedling was placed in polypropylene falcons with 30 ml distilled water. Each of the samples was shaken for 3 h on a shaker (Labnet, Rocker, USA) to measure the electrolytes leakage from living seedlings (EL). Electrolyte leakage was measured by conductometer (CX-701, Elmetron, Poland) with electrode (K = 1.02) (Elmetron, Poland). The seedlings in distilled water were frozen at -75 °C for 24 h. The next day, samples were defrosted and shaken for 3 h to determine the total electrolyte leakage from dead seedlings (ED). The total percentage of electrolyte leakage was determined according to the formula: EL = (EL/ ED) × 100

Statistical analysis
The experiment was performed in three repetitions. The obtained results were statistically tested between repetitions of the experiment (n = 3, ±SE) as well as between cultivars, habitats extracts, and organ extracts using the Duncan test at p < 0.05 with Statistica software.

Germination indexes
The percentage of seeds germinated was the highest in the control. A decrease in seed germination capacity was observed with the increase in the concentration of aqueous extracts. The smallest differences were found between the control and 1% of Filipendula vulgaris root and shoot extracts regardless of the habitats.
The lowest number of germinated radish seeds was found on the 10% dropwort extracts. More germinated seeds were observed on root extracts than on shoots ( Figure 2).
The seed vigour index (SVI) reached the significantly highest values for the investigated radish cultivars watered with the 1% aqueous extracts of F. vulgaris roots, compared to the control. In the case of extracts from shoots, the highest values of this parameter were recorded for the 'Krakowianka' cultivar treated with 1% and 5% of the extracts of plants growing on calcareous grassland. Regardless of the radish cultivar and the extract type, the lowest SVI values were found for seeds germinated on the 10% extracts (Table 1). Speed emergence (SE) values for radish seeds watered with root extracts, both from meadows and calcareous grasslands, were similar to the control at each concentration. The exception was 10% calcareous grassland root extracts, which significantly limited the SE. Aqueous extracts from shoots with a concentration of 1% did not affect the values of this parameter. Compared to the control samples, 5% and 10% extracts, especially from shoots obtained from calcareous grasslands, inhibited SE.
In comparison with the control, the only significant differences in the values of the rate of germination (RG) index were demonstrated for the 'Krakowianka' cultivar watered during germination with 10% shoot extracts from calcareous grassland. In other cases, in the values of this index, no statistically significant differences were observed.
Mean germination time (MGT) reached similar values between the control and 1% F. vulgaris root and shoot extracts from both meadow and calcareous grassland. In the 'Rowa' cultivar, a lower value of this index was revealed for seeds treated, regardless of the concentration of the extract, with dropwort plant root extracts from the meadow. For the 'Krakowianka', significant differences were found only for seeds watered with 10% extracts. Control -distilled water, 1, 5, 10RM -1%, 5%, 10% extract from root plant grown on meadow, 1, 5, 10RCG -1%, 5%, 10% extract from root plant grown on calcareous grasslands, 1, 5, 10SM -1%, 5%, 10% extract from shoot plant grown on meadow, 1, 5, 10SCG -1%, 5%, 10% extract from shoot plant grown on calcareous grasslands In the remaining cases, irrespective of the cultivar, significant differences were observed between the control and extracts of 10% root extracts from calcareous grasslands and 5% and 10% shoot extracts from plants grown on meadows and calcareous grasslands.
In the case of plant shoots collected from meadows, the elongation of this radish organ was decreased. The 10% extracts from roots obtained from calcareous grasslands and meadows also had a negative impact on root length. For seedlings watered with 5% extracts from shoots collected on calcareous grasslands, significant root elongation was observed ( Figure 3A).
The aqueous extracts from the roots and shoots of dropwort had a positive effect on the elongation of the hypocotyl of radish seedlings, 'Rowa' and 'Krakowianka' cultivars, concerning the control. Generally, hypocotyl growth stimulation was observed with increasing concentrations ( Figure 4A). The horizontal line is the border with negative values that indicate elongation stimulation and positive values that indicate the percentage of inhibition of seedling growth; RM -extract from root plant grown on the meadow, SCGextract from shoot plant grown on calcareous grasslands; mean values (n = 3, ±SE) marked different letter differ statistically according to Duncan test at p < 0.05 Biometric analysis of whole seedlings revealed a stimulating effect for both radish cultivars, extracts from 1% of roots and 5% of shoots. Besides, a positive effect of shoot extracts at concentrations of 1% and 5% from calcareous grasslands was observed. Compared to the control, 5% root extracts of calcareous grassland plants also showed stimulation of seedling elongation ( Figure 5A).
Morphometric analysis of the under-and aboveground organs of radish seedlings by determining the IP index as a percentage of control confirmed the positive and negative effect of extracts from F. vulgaris on the roots, hypocotyls, and whole radish seedlings in two cultivars. For this index, positive values indicate a higher percent growth inhibition. On the other hand, negative values show the positive influence of the extracts on organ elongation. The root length was inhibited by extracts with 10% concentrations, regardless of the dropwort organs. Contrary to the 1% extracts, which stimulated the growth of radish seedlings ( Figure 3B). Elongation of the hypocotyls was stimulated relative to the control ( Figure 4B). The length of the whole seedlings was generally stimulated, but to the highest extent by 1% dropwort extracts ( Figure 5B). The smallest effects were found for extracts from shoots from calcareous grasslands (Figures 3-5).  Control -distilled water, 1, 5, 10RM -1%, 5%, 10% extract from root plant grown on meadow, 1, 5, 10RCG -1%, 5%, 10% extract from root plant grown on calcareous grasslands, 1, 5, 10SM -1%, 5%, 10% extract from shoot plant grown on meadow, 1, 5, 10SCG -1%, 5%, 10% extract from shoot plant grown on calcareous grasslands; mean values (n = 5, ± SE) marked different letter differ statistically (in row) according to Duncan test at p < 0.05 Fresh, dry mass, and water content The fresh mass of 'Rowa' radish seedlings was significantly highest for the seeds watered with 10% of the shoots from the meadows, compared to the control. Significantly the lowest fresh mass value of seedlings was found for seeds watered with 5% of F. vulgaris shoot extracts from calcareous grasslands. For the 'Krakowianka', no statistically significant differences in the fresh mass values were observed between the control and the extracts from the dropwort organs used (Table 2).
In the case of dry mass, its significant increase was demonstrated for seedlings of 'Rowa' cultivar grown from seeds watered with 5% root extract from meadow areas, compared to the control. In other cases, no significant differences in the values of this parameter were observed.
In general, for the 'Rowa' cultivar a percentage of the dry mass index was significantly higher for seedlings grown on root extracts than shoot extracts. For the 'Krakowianka', no differences in the values of this index were found. The total water content was the lowest in 'Rowa' seedlings grown from seeds watered with 5% root extracts from the meadow, compared to the control and all tested extracts. For the 'Krakowianka' cultivar, no changes in the percentage of water content were observed (Table 2).

Electrolyte leakage
The percentage of electrolyte leakage was the highest in the control for both radish cultivars. For radish seedlings watered with 1% root extracts from meadows, similar values of this parameter were observed. The lowest degree of cell membrane destabilisation, for seedlings watered with 10% of the root extracts from meadows and 5% of the shoot extracts from calcareous grasslands, was measured. In the remaining extracts, the electrolyte leakage values were significantly lower than in the control group ( Figure 6).

Discussion
A growing interest in the use of allelopathic plants is observed, both in the direct use as plants controlling weeds as well as attempts to isolate specific compounds of high biological activity as natural herbicides (Duke et al., 2002;Singh et al., 2003;Golisz et al., 2004). The medicinal plants are considered an important source of secondary metabolites and recently they are studied in case of herbicidal potential in controlling major crop weeds for sustainable agricultural production. The possibility to have more bioactive compounds in medicinal plants than in other plants stand behind the special interest in this group of species. As a result of the researches, a considerable number of examined medicinal plants exhibited allelopathic properties (Islam et al., 2018). The studies investigated the suppression of extracts from medicinal plants on model plants like lettuce (e.g. Amini et al., 2016), radish (e.g. Haugland and Brandsaeter, 1996), chosen weeds (e.g. Boonmee and Kato-Noguchi, 2019), or other cultivated species (e.g. Puła et al., 2020). This study showed the allelopathic effect of aqueous extracts from Filipendula vulgaris roots and shoots on germination and early stages of growth of model radish seeds in two cultivars. The percentage of seed germination was decreased with the increase in the concentration of aqueous extracts. The smallest differences were found between the control and 1% of Filipendula vulgaris root and shoot extracts regardless of the habitats. The highest inhibition of germination capacity seeds was observed on the 10% dropwort extracts. On the root extracts, more percentage of germinated seeds were observed than shoots extracts (Figure 2). In general, the performed determinations of germination indexes showed that extracts with 1% concentration significantly stimulated seed germination. On the other hand, dropwort extracts with a concentration of 10% had an inhibitory effect on the germination capacity, regardless of the radish cultivars (Table 1). Germination depends on many factors biochemical and molecular, from the activation of the metabolism of the embryo embedded in the seed, the quality of the RNA and the integrity of the DNA, plant hormones (Koorneef et al., 2002;Rajjou et al., 2012). In the germination process many enzymes participate, which activity in the presence of allelopathic compounds can be destabilized. Reducing the activity of hydrolytic enzymes means that the seeds are not able to provide enough energy for germinating seeds, which reduces the germination capacity and causes the formation of weakened seedlings Możdżeń et al., 2020). Allelochemical substances increase the vacuolization of cells, which is accompanied by a reduction in the number of mitochondria, the density of ribosomes, and dictiosomes (Burgos et al., 2004). The seed coat can also play an important role, as it protects the seed against harmful external factors and mechanical damage (Rzepka and Stachurska-Swakoń et al., 2018;Mazur, 2019).
It is easily permeable to oxygen and water. The lower concentration of allelopathic compounds in 1% extracts means that more water is absorbed by the seeds, hence perhaps a positive influence of extracts of low concentrations on the values of selected germination indexes, and no differences between the control samples and dropwort extracts was observed. Root or leaf extracts may also contain diverse phytotoxins with different modes of action (Inderjit et al., 2007). Therefore, it can be assumed that the different reactions of radish seeds result from a different concentration of allelochemical compounds in aqueous extracts from roots and shoots.
Understanding the mechanisms of action of allelochemical compounds on plants is difficult, if only because they belong to different chemical classes and it is difficult to expect them to act in the same way. It is assumed that allelochemical compounds affect comprehensively. Moreover, allelochemicals present in the plant after reaching the rhizosphere can be quickly converted into compounds with greater or lesser activity. Therefore, it is important to assess the concentration and form in which the allelochemical is available for the species. It should also be considered how the habitat, physical, chemical, and biological soil factors, climatic conditions influence the qualitative effects and quantitative concentration of a given compound (Kaur et al., 2005). There is a close correlation between the occurrence of environmental stresses that directly shape plant growth and stimulation of phytotoxic production (Saxena et al., 1996;San Emeterio et al., 2007;Gioria and Osborne, 2014). As a result, it leads to morphogenetic changes and affects the size and quality of the crop (Rice, 1984;Einheling, 1995). The growth of plants is a very sensitive process to the presence of allelochemical compounds. Allelochemical compounds reveal their effect already during seed swelling, affecting the cells of the seed coat and aleurone layer, mitotic cell division, shaping cell organelles, and also elongation. They usually distort the cell walls in the cells of the apex of the root growth and contribute to the accumulation of lipids in the cytoplasm of the cells (Wójcik-Wojtkowiak et al., 1998;Kaur et al., 2005). According to Burgos et al. (2004), inhibition of seed cell growth is caused by disturbances in lipid metabolism and the reduction of protein synthesis. In our study, when considering biometry, a stimulating effect of 1% of F. vulgaris root and shoot extracts obtained from the meadow and calcareous grassland on hypocotyle length was observed. As the concentrations increased, the elongation of seedling organs was inhibited (especially on 10% extracts) ( Figures  3-5).
The aqueous extracts of the dropwort roots and shoots did not significantly influence the fresh and dry mass ( Table 2). The allelopathic effect of F. vulgaris depended on the concentration of the extracts. Only the 'Rowa' presented a slight increase in the fresh mass of seedlings on 5% of F. vulgaris shoot extracts from calcareous grasslands and dry mass on 5% root extract from meadow areas. Similarly, no differences in water content in seedlings were found. These results suggest the presence of different concentrations of soluble allelochemical substances in the aqueous extracts of dropwort. The higher toxicity of meadow extracts than calcareous grassland is probably related to the presence of more amounts of allelopathic compounds in plants.
Their toxicity may be due to also a synergistic action, and not only to the action of individual substances. The concentration of a chemical in solution may be significantly less than the concentration of a single allelopathic substance required to produce a plant growth inhibitory effect (Xuan et al., 2004;Inderjit et al., 2007).
Allelopathic compounds have a primary effect on cytoplasmic membranes. Their damage affects the entire metabolism and all physiological processes (Wójcik-Wojtkowiak et al., 1998). In this research, a significant reduction in the degree of destabilization of cell membranes, regardless of the extract used, was found. However, it was lower than in the control, which is an interesting result ( Figure 6). This radish seedling response may be due to the lower content of phenolic compounds in leaves than in flowers . Recent studies on the extracts of F. vulgaris revealed that they contain several classes of phenolic compounds (Katanić et al., 2018). Flavonoid glycosides have been described as a major constituent of the upper parts of dropwort, and catechin and procyanids were identified as a major constituent of roots (Oszmiański et al., 2007). Such a reaction of seedlings also depends on the harvest period of the plants from which the extracts were prepared. Bączek et al. (2012) have found seasonal variation in the content of phenolic compounds in the upper parts of the species, they were higher at the beginning of flowering as compared with the full flowering stage. Additionally, the content of catechins and polyphenolic acids found in the roots did not change during the season. In the present study, F. vulgaris plants were harvested in the late generative stage, which probably reduced the electrolyte leakage. On the other hand, we cannot exclude the probable presence of calcium in F. vulgaris extracts, the role of which in membrane stabilization is known (Hepler, 2005).
It is commonly believed that plants have a negative allelopathic effect on other plants, but some of them also play a positive role. Some plants contribute to the protection of soils against erosion, improve their fertility, and have a positive effect on the condition of the soil microflora. Allelochemical compounds secreted by plants that stimulate the growth of other plants are also known. However, they constitute a small group compared to allelochemicals compounds inhibitory (Haupt et al., 2001;Goufo et al., 2014;Kopczewski, 2014). Our study pointed at the inhibiting effect of all extracts on germination capacity. At low concentrations of aqueous extracts from the roots and shoots of dropwort the germination indexes had higher values than control. The biometric and biomass parameters of seedlings were generally stimulated by these extracts, regardless of the plant harvesting habitats, organs, and concentrations, as compared to the control seedlings. Therefore, it is necessary to conduct further research on the allelopathic interactions of plants to understand their effects not only on seed germination but also their physiology and plants grown from them. Additionally, it seems necessary to study the chemical composition to identify chemical compounds responsible for this type of reaction and to strive for their practical application in various fields. Multidisciplinary studies involving plant ecology, genetics, physiology, biochemistry, soil science, and microbiology can answer the key questions of if and how allelopathy influences plant interactions.

Conclusions
Plants, in order to survive in the natural environment, developed many defence mechanisms, including the ability to synthesize and secrete compounds with allelopathic potential. In the literature, there are various groups of allelochemical compounds as well as the sources of their release into the environment. The release of substances with the allelopathic potential to the environment may inhibit or stimulate seed germination and plant growth. Their impact on other organisms depends on their chemical nature, the species they affect, and the prevailing environmental conditions. This study revealed the inhibiting effect of aqueous extracts from Filipendula vulgaris organs on the germination of two cultivars of radish seeds. However, the stimulating effect of 1% of aqueous extracts from dropwort roots and shoots on the germination indexes was revealed. As the concentration of allelopathic compounds in the extracts increased, a decrease in the values of germination indexes was observed, compared to the control. Similarly, the biometry of radish seedlings revealed a positive effect of extracts with low concentrations, as opposed to extracts with a higher content of allelopathic substances (especially, 10% extracts). Observations of changes in the length of the root organs, hypocotyls, and whole seedlings were similar, regardless of the type and concentration of the extract, concerning seedlings grown on distilled water.
For the 'Rowa' cultivar, an increase in the fresh mass of seedlings with an increase in the concentration of extracts was demonstrated, in contrast to the 'Krakowianka'. The dry mass values generally no significant differences were changed. The exception was 'Rowa' cultivar grown from seeds watered with 5% root extract from meadow areas, where the dry mass was lower. The percentage of dry mass depended on the concentration and type of extract used for watering the radish seeds. A positive effect of 5% and 10% extracts was observed, regardless of the organ used in preparing the extract. A positive effect of all dropwort extracts on the electrolyte leakage was demonstrated.
Authors' Contributions ASS planned and designed the research; MF, KM performed the experiment; ASS, KM, BBK, MF analysed the data and prepared figures and tables, ASS, KM, BBK wrote the manuscript. All authors read and approved the final manuscript.