Seeds’ similarity of cultural and natural flora under chloride load in conditions of southern Ukraine

Saline soils make up almost 25% of the entire earth’s surface. Their areas, unfortunately, have a steady tendency to expand due to the aridization of the climate and the global increase in the average annual air temperature of the planet. The increased concentration of salts in the soil limits the diversity of cultural and conditions the poverty of natural flora, forms areas of risky agriculture in the south of Ukraine. Seeds are a unique product of evolution, the main generative organ of plants, characterized by a number of morphological, physiological and biological features, among which there is adaptation heterogeneity. It is established that by the number of germination days (the seeds of the cultural flora sprouts for 7–10 days, and in wild representatives this indicator extends to 10–12 days) the plants can be arranged in the following order: seven days –Secale cereale L., Triticum durum L., Avena sativa L., Hordeum vulgare L., Helianthus annuus L., Matricaria recutita L.; ten days – Beta vulgaris L., Phaseolus vulgaris L. and twelve days – Valeriana officinalis L. It is found that the most optimal for germination is the aquatic environment, so the plants are arranged according to the list: Helianthus annuus L. → Avena sativa L. → Triticum durum L. → Matricaria recutita L. → Secale cereale L. → Hordeum vulgare L. → Beta vulgaris L. → Valeriana officinalis L. → Phaseolus vulgaris L. It is proved that Na+ and Cl–ions differentially affect the seed germination energy: at a concentration of 0.1% NaCl – Triticum durum L. → Helianthus annuus L. → Hordeum vulgare L. → Secale cereale L. → Phaseolus vulgaris L. → Avena sativa L. → Matricaria recutita L. → Beta vulgaris L. → Valeriana officinalis L.; at a solution concentration of 0.2% NaCl – Secale cereale L. → Triticum durum L. → Helianthus annuus L. → Avena sativa L. → Matricaria recutita L. → Hordeum vulgare L. → Phaseolus vulgaris L. → Valeriana officinalis L. → Beta vulgaris L. The results obtained indicate that the chloride load in the seeds of plants manifests itself in the form of distress as well as eustress. It has been proved that the diagnostic features of chloride hermesis were more clearly manifested in the representatives of the cultural flora than the natural ones.


Introduction
Due to increasing anthropogenic pressure on the environment, the climatic conditions on the planet Earth are changing [1].Saline soils make up almost 25% of the earth's surface (about 1254 (2023) 012016 IOP Publishing doi:10.1088/1755-1315/1254/1/012016 2 9 • 10 8 ha).Unfortunately, their areas tend to expand due to climate aridization and an increase in the average annual temperature of the planet [2,3].In Ukraine, about 1 million hectares of land have varying degrees of soil salinization.The south of Ukraine forms a zone of risky agriculture characterized by temperate continental climate with hot summers, high solar insolation and significant water deficit [4,5].Poverty and specificity of both natural and cultural flora is conditioned by the presence of the sea area (sea, estuaries), intensive evaporation of water during irrigation, soil salinization [6,7].Seeds are a unique product of evolution, the main generative organ of plants, characterized by a number of morphological, physiological and biological features, among which there is adaptation heterogeneity [8,9].Therefore, research on the similarity of plant seeds to salt stress is becoming increasingly relevant.
Hence, the research aim is to find out the seeds' similarity of natural and cultural flora under chloride load in southern Ukraine.

Material and methods
The researches object was the seeds of the following plant species that prevail in the herbaceous cultivated and wild vegetation of southern Ukraine: Beta vulgaris L., Secale cereale L., Triticum durum L., Avena sativa L., Phaseolus vulgaris L., Hordeum vulgare L., Helianthus annuus L., Valeriana officinalis L., Matricaria recutita L. The artificial level of salinity in the laboratory and vegetation conditions was created by adding the appropriate amount of salt to the water when wetting and subsequent irrigation according to the scheme: K -natural conditions, option 1 -vegetation and laboratory control (growing seeds in water), option 2 -growing in 0.1% NaCl salt solution, option 3 -growing in 0.2% NaCl salt solution of.The choice of concentration of chloride salts is explained by the fact that such percentage is considered stressful for seeds [4,10].Representatives of cultural flora are hybrids and varieties, which are located in the south of Ukraine [6].The seeds of the experimental plants of the wild flora were collected from hills associations of Zaporizhzhya region (Bogatyr, Terpinnia).The physiological aspects of determining the germination energy of the experimental plants and their similarity were performed according to conventional methods [9].Laboratory and vegetation experiments were conducted on the basis of the Bogdan Khmelnitsky Melitopol State Pedagogical University, and the field experiments on the basis of Novotroitsky Farm "Niva".Statistical analysis of the obtained data was performed using Microsoft Excel and Statistica 8.0.For comparison of samples, arithmetic mean (M) and standard error from mean (SEM) were calculated.The difference p 0.05 was considered statistically significant for all indicators.

Results
Due to the irrigation of crops, the number of saline soils is increasing annually [6,11].Therefore, the study of the adaptive capacity of seeds of representatives of natural and cultural flora to different concentrations of chloride salts will bring us closer to understanding the strategy of adaptive transformations.
The obtained experimental data showed that the seeds of Secale cereale L. sprouted 93% in aqueous solution for 3 days (figure 1, A), 89% -in 0.1% NaCl solution, 95% -in 0.2% NaCl solution.At 5 days, this indicator had the following values: in aqueous solution -93%, in 0.1% NaCl solution -95%, in 0.2% NaCl solution the number of sprouted seeds increased to 100%.At 7 days, the percentage of seed germination did not change.Our data are in agreement with the opinion of several authors [12], that cereals during germination have a classic effect of gibberellins, associated with the release of seeds from a resting state, and gibberellin "start" formation of amylases is a prerequisite for germination.
The experimental data (figure 1, B) showed that the seeds of Triticum durum L. sprouted well in NaCl solutions with a concentration of 0.1% and 0.2% by the third day.It is shown that in the aquatic environment 98% of the seeds sprouted on the 3rd day; the percentage did not change on the 5th and 7th days.In NaCl solutions with a concentration of 0.1% and 0.2% 100% of the seedlings sprouted on the third day, which may be due to the activation of protective reactions under the action of lections [13], gibberellins, which stimulate the processes of grain germination [14].
Seed germination of Avena sativa L. (figure 2, A) showed that on the 3rd day the number of sprouted seeds in water was 50%, on the 5th and 7th day it increased to 99%.In 0.1% NaCl solution on the third day germinated -83%, the fifth and the seventh -90%, but in 0.2% NaCl solution on the third day -11% of seeds, the fifth and the seventh -95%.During the seven-day period, the largest amount of seeds sprouted in water, although on day 3; 0.1% NaCl solution was the best conditions for the seeds.Germination was more stable in 0.2% NaCl solution.It is known that lections are involved in the process of seed germination and ripening [13].
The obtained results proved that the germination of seeds of Hordeum vulgare L. began on the third day (figure 2, B), with the highest values observed in 0.1% NaCl solution -95%, in the aquatic environment -93%.This pattern remained for the fifth and seventh days of the experiment.In 0.2% NaCl solution, the smallest number of grains sprouted: 23% on the third day, and on the fifth and seventh -88%.The faster the germination process occurred with the seeds that germinated in water, the longer the germination occurred in solutions.
Thus, our results illustrated that Na + and Cl − ions at 0.1% concentration stimulate seed germination for the third day after sowing, this position is confirmed by the works of several authors [7,11].Water, penetrating through the pollen and the skin into the intercellular spaces and cells, removes the seed germ from a state of rest.Organic compounds present in the endosperm undergo certain changes, in particular, increased respiration and activated enzymes, under the influence of which the spare substances are converted into easily digestible forms.
It has been proved [9,14] that in cereals during germination there is a classical effect of gibberellins associated with the release of seeds from rest.After the seeds absorb through the micropyle of water, the embryo in the area of the shield begins to synthesize GA3, GA4 gibberellins, which are transported to the aleurone layer surrounding the endosperm, and stimulate the formation of hydrolytic enzymes (α-amylases, etc.).Enzymes begin to break down the spare starch of the endosperm to the simple sugars used for embryo growth and development.Thus, gibberellin "start" formation of amylases is a prerequisite for seed germination.The mechanism of this process is not fully understood.Gibberellins are thought to stimulate amylase-specific m-RNA synthesis.
Our studies showed that during the germination of Beta vulgaris L. seeds (figure 3): the first sprouts appeared on the fifth day in pure water -up to 30%, in 0.1% NaCl solution -up to 20% and the smallest amount was observed in 0.2% NaCl solution -up to 2%.On the 7th day the highest amount of seeds sprouted in water was 70%, 60% in 0.1% NaCl solution, and the smallest in 0.2% NaCl solution up to 30%.On the tenth day the most seeds germinated in water 80%, 75% in 0.1% NaCl solution, and in 0.2% NaCl solution -35%.Therefore, in Beta vulgaris L., the best germination occurs in water and in 0.2% NaCl solution the worst.
It is found that the seedlings of Phaseolus vulgaris L. began to appear on the third day (figure 4) in the sample with water and in 0.1% NaCl solution.Up to 50% of seeds have sprouted in the aqueous medium for 5 days, less than 40% in 0.1% NaCl solution, and 20% in 0.2% ones.On the seventh day, in all samples, the number of sprouted seeds increased: 60% -in water, 65% -in 0.1% saline, 45% -in 0.2% NaCl solution.El Amrani et al [15] have investigated the physiological role of seed lections -phytohemagglutinin (PHA).The protective role of PHA in germination of seeds, based on the ability of lection to be released into the environment, and, due to specific interaction with the constituent cell walls of pathogenic bacteria, is shown to cause a delay in their growth.
According to the results of germination of seeds of Helianthus annuus L. it was found that for 3 days the most seeds germinated in aqueous medium, in 0.1% NaCl solution -60%, 0.2% NaCl solution -more than 20% (figure 5).On the fifth and seventh days, 100% of the seeds sprouted in all samples.Consequently, low-concentration salt solutions at the initial stage of germination promote rapid unfolding of physiological and biochemical processes in seeds [12].It is proved that the rate of germination of Helianthus annuus L. seeds is characterized by inversely proportional dependence on the salt concentration in the medium.
Analysis of the experimental results obtained from germination of Valeriana officinalis L. seeds (figure 6, A) showed that by 3 days the highest amount of 20% sprouted in 0.2% NaCl solution, the smallest in water (10%) and 0.1% NaCl solution (0%), on the fifth day of the seeds is located in aqueous medium and solution of salts with a concentration of 0.1% NaCl the percentage of germination did not change, but 20% reached the germination energy in saline solution of 0.2% NaCl.Seed germination of Valeriana officinalis L. was observed for twelve days, but during this period the highest values were obtained in the aquatic environment, the lowest -in 0.1% and 0.2% saline solutions.Therefore, it can be assumed that, under the action of water, the seed cell enzymes have gone from an inactive state to an active and insoluble   spare substances have become soluble (starch -into sugar, fats -into glycerol and fatty acids, proteins -into amino acids).The embryo, using soluble organic compounds, began active growth and development [3].
The results of germination of Matricaria recutita L. seeds in water; 0.1% and 0.2% NaCl solutions had the following values: on the third day the seeds germinated intensively in the aquatic environment and were more than 90%, less intensive germination occurred in 0.2% solution salts -more than 93%, the lowest amount of 83% was observed in 0.1% NaCl solution (figure 6, B).
On the 5th day in water, the percentage was more than 95% in the aqueous medium, in 0.2% NaCl solution -94%; in 0.1% NaCl solution -more than 85%.At 7 days the number of germinated seeds in the studied media did not change.For the entire germination period, which was seven days, the highest values were observed in water, the average values were in 0.2% NaCl solution and the lowest values were in 0.1% NaCl solution.This is explained by the fact that when germination of seeds in water and solutions of salts with different concentrations, gibberellins are activated in different periods of growth and development [13,16].
The analysis of the results shows that the stress tolerance of plant seeds to salinization is already manifested in the germination phase, thanks to the realization of genetically-laid potential.

Conclusions
The study of seeds' salt hermesis of natural and cultural flora in the conditions of southern Ukraine showed that the number of days of germination (seeds of cultural flora germinates for The results obtained indicate that the chloride load in the seeds of plants manifests itself in the form of distress as well as eustress.It has been proved that the diagnostic features of chloride hermesis are more clearly manifested in the representatives of the cultural flora than the natural ones, which is caused by the implementation of the interrelation of the genetic program and phenotypic manifestations, which are related to the special climatic conditions of southern Ukraine (soil salinity, air and soil drought, etc.), which is of practical importance when developing strategies for growing crops on saline soils.

7 -
10 days, and in wild representatives this indicator is extended to 10-12 days) plants can be arranged in the following order: seven days -Secale cereal L., Triticum durum L., Avena sativa L., Hordeum vulgare L., Helianthus annuus L., Matricaria recutita L.; 10 days -Beta vulgaris L., Phaseolus vulgaris L. and 12 days -Valeriana officinalis L. The aquatic environment is the most optimal for germination, but the numbers of sprouted seeds plants are in accordance with the list: Helianthus annuus L. → Avena sativa L. → Triticum durum L. → Matricaria recutita L. → Secale cereale L. → Hordeum vulgare L. → Beta vulgaris L. → Valeriana officinalis L. → Phaseolus vulgargaris L. → Phaseolus vulgaris L. The study of seed stress tolerance demonstrated the differentiation of the influence of Na + and Cl − ions (at a concentration of 0.1%) on physiological and biochemical processes, which led to the appropriate distribution of plants: Triticum durum L. → Helianthus annuus L. → Hordeum vulgare L. → Matricaria recutita L. → Beta vulgaris L. → Valeriana officinalis L. The concentration of 0.2% NaCl solution revealed the following sequence: Secale cereal L. → Triticum durum L. → Helianthus annuus L. → Avena sativa L. → Matricaria recutita L. → Hordeum vulgare L. → Phaseolus vulgaris L. → Valeriana officinalis L. → Beta vulgaris L.