Gypsophila volgensis Krasnova (Caryophyllaceae) is a representative of the calcicolous flora endemic to the Middle and Lower Volga regions of Russia and occurs between latitudes 49 degrees and 54 degrees N. The growing conditions of the species differ in the content of calcium salts in the soil, the supply of mineral elements and moisture, temperature, sunshine hours, and precipitation. The aim of this work was to study the changes in the morphological, physiological, and biochemical characteristics of the leaves of G. volgensis under changing ecological conditions between latitudes 49 degrees and 54 degrees N. The data obtained showed that temperature, number of sunshine hours, HCO3-, and soil acidity influenced changes in plant leaf properties and were positively associated with leaf mass per unit area, malondialdehyde, and water-soluble phenolics. At the same time, temperature and light conditions were negatively related to leaf area and the concentrations of chlorophylls, membrane proteins, sugars, and lipids, while edaphic factors such as Ca2+ and SO42-were positively associated with these parameters. Precipitation affected such leaf parameters as water-soluble proteins, proline, carotenoids, and glycolipids. The study's findings show how the calcicole G. volgensis can adapt to shifting climatic and local edaphic conditions by altering the morphological, physiological, and biochemical traits of its leaves. If G. volgensis spreads beyond its natural geographic range, the direction of change in the functional characteristics of its leaves can be predicted.

Potato (Solanum tuberosum L.) is one of the most important and most popular agricultural crops in Russia. Breeding science creates many new varieties to increase the biological and economic potential of potato. One of the criteria for inclusion in practical breeding is high productivity combined with resistance. This approach is based on the study of phenotype under specific environmental conditions. The aim of the work is to evaluate the relationship between yield components and quality of potato tubers. The objects of study were 29 potato varieties of different ripeness groups and genetic origin: early, medium early and mid-season variety. Field research was carried out at the experimental plot of the Samara Scientific Re-search Agriculture Institute named after N.M. Tulajkov – branch of the Samara Federal Research Scientific Center RAS in 2022-2024. As a result of field experiments, higher yields of early variety, medium early variety and mid-season were established. The correlation coefficients between yield and tuber number and yield and tuber weight are r = 0.59 and r = 0.71 at p < 0.05, respectively. A positive correlation was established for yield and plant height (r = 0.29). A mean positive relationship linked starch content and tuber number (r = 0.39) but negative relationship was found for ascorbic acid content and tuber weight (r = 0.28). Thus, it is necessary to take into account the relationship of tuber biochemical composition with yield and growth parameters in breeding programmes.

Potato (Solanum tuberosum L.) is one of the main non-grain agricultural crops and one of the main sources of food for humanity. Currently, growing potatoes requires new approaches and methods for cultivation and breeding. Phenotyping is one of the important tools for assessing the characteristics of a potato variety. In this work, 29 potato varieties of different ripeness groups were studied. Linear leaf dimensions, leaf mass area, number of stems, number of tubers per plant, average tuber weight, signs of virus infection, dry weight, pigment content, and number of stomata per unit leaf area were used as phenotyping tools. The strongest positive relationship was found between yield and bush area in the stage of full shoots (R = 0.77, p = 0.001), linear dimensions of a complex leaf (R = 0.44, p = 0.002; R = 0.40, p = 0.003), number of stems (R = 0.36, p = 0.05), and resistance to viruses X (R = 0.42, p = 0.03) and S (R = 0.43, p = 0.02). An inverse relationship was found between growth dynamics and yield (R = −0.29, p = 0.05). Thus, the use of morphological and physiological phenotyping tools in the field is informative for predicting key agricultural characteristics such as yield and/or stress resistance.

Twenty-four potato (Solanum tuberosum L.) varieties differing in ripening groups (early, middle-early, and mid-season-ripening) were studied. Potatoes were grown under the conditions of the Middle Volga region of Russia in 2019–2021. It was found statistically that the yield (t/ha) of the early and mid-season-ripening varieties was negatively correlated with the increase in average temperatures during the growing season from May to August (R = –0.97, p = 0.04). Soil moisture content at a depth of 20 cm was positively correlated with the yield of middle-early varieties (R = 0.97, p = 0.04). The average tuber weight in the early varieties was sensitive to the increase in average temperatures (R = –0.95, p = 0.04). An increase in soil moisture content was beneficial to the average tuber weight (R = 0.98, p = 0.04), though only in the middle-early and mid-season-ripening groups. However, the soil moisture content and the tuber numbers in the mid-season-ripening varieties were negatively correlated (R = –0.96, p = 0.05).

Effects of 1 M NaCl on the lipid profile of detergent-resistant membranes in chloroplasts and mitochondria of salt-accumulating halophyte plants of family Amaranthaceae, Salicornia perennans Willd. and Suaeda salsa (L.) Pall. were studied. The composition of lipids and fatty acids in detergent-resistant membranes differed from total lipids of chloroplast and mitochondrial membranes by the abundance of cerebrosides and sterols. Under the given salinity level, a manyfold increase in the relative content of cerebrosides was noted in the composition of detergent-resistant chloroplast membranes of S. perennans. A similar salinity-related increase in cerebroside content was detected in detergent-resistant mitochondrial membranes of S. salsa. The opposite effect was observed for sterols: their relative content decreased under the action of salt. The results indicate that the detergent-resistant membranes are involved in the interactions of chloroplasts and mitochondria in the cell response of halophytes to salinity.

The parameters of adaptability and stability of the genotype on the basis of productivity in 14 varieties of potatoes of domestic selection were evaluated. The research was carried out in the fields of the Samara Scientific Research Agriculture Institute in 2019-2022 under conditions of moisture deficiency and high air temperature. According to the average yield over the years of research, medium-early varieties of Krasa Meschery, Debut, Sudarinya, as well as medium-ripe Siversky and Alaska were distinguished. The most balanced indicators of plasticity and stability when using two different methods for their evaluation were found in the Debut variety. The varieties Plamya, Legenda, Sudarinya and Signal are also distinguished as valuable genotypes. It was found that the value of the variety in the agroecological conditions of the research area was primarily determined by indicators of crop stability in different years. Environmentally plastic and neutral potato varieties may have an advantage in these conditions.

The ecological, morphological, physiological, and biochemical characteristics of representatives of the genus Galium (Rubiaceae) have been studied. The objects of study are the hybrid (nothospecies) Galium × affrenum (Klokov) Ostapko (=nothospecies) and its parental species G. ruthenicum Willd., and G. octonarium (Klokov) Pobed. s. l. G. × affrenum is habitually closer to G. ruthenicum; however, it differs from the latter in pale lemon flowers. Based on the method of artificial neural networks, it is shown that the nothospecies is closer to the parental species G. octonarium with respect to physiological and biochemical features. The leaf biomass of G. × affrenum is characterized by an increased content of photosynthetic pigments and a greater variability in the concentration of photosynthetic pigments and lipid metabolism, which may be key to its greater stability and viability.

The purpose of the study is to identify the relationship between drought resistance indicators and the yield of potato plants under unfavorable conditions. A xeromorphic leaf structure is considered a diagnostic sign of plant drought resistance. The objects of the study were 24 potato varieties. Planting of seed, pre-planting tillage, harvesting and crop recording were carried out in the period 2020-2022 on the territory of the Samara Research Institute of Agriculture - a branch of the Samara Scientific Center of the Russian Academy of Sciences. Growing conditions for 2021 and 2022 characterized by elevated temperatures and insufficient moisture. The number and size of stomata per unit leaf area were chosen as the criterion for xeromorphism. The studied varieties were divided into two groups (n=12 each) according to the number of stomata. In the first group, the average number of stomata was 26 thousand pcs./cm2 of leaf, and in the second group - 35 thousand pcs. (F=41, p=0.03). More developed structural features of xeromorphism and the accumulation of certain types of metabolites in the second group of varieties led to a 1.6 times greater yield than in the first less xeromorphic group (F=9, p=0.004). The second group was characterized by a large number of mesophyll cells per unit leaf area (584 thousand pieces/cm2 versus 557 thousand pieces), a high content of phospholipids (36 mg/g dry weight versus 31 mg/g), dry weight (0.19 vs. 0.17 g/g wet weight) and the ratio of membrane lipids to membrane proteins (1.4 vs. 1.2). In the less xeromorphic group of plants, the level of oxidative stress, assessed by LPO products, was 0.050 µM/g fresh weight and was 12 % higher than in the more xeromorphic group (F=6, p=0.08). The revealed positive correlation between yield and xeromorphic genotypes indicates the prospects of using this criterion in potato breeding or creating a variety model.

Halophytes represent important models for studying the key mechanisms of salt tolerance. One approach to the development of new knowledge of salt tolerance is to study the properties of detergent-resistant membranes (DRMs). In this work, the lipid profiles of DRMs of chloroplasts and mitochondria of euhalophyte Salicornia perennans Willd, before and after their exposure to shock concentrations of NaCl, have been investigated. We found that DRMs of chloroplasts are enriched in cerebrosides (CERs) and that sterols (STs) dominate the mass of mitochondrial DRMs. Also, it has been proven that (i) the impact of salinity provokes obvious growth in the content of CERs in DRMs of chloroplasts; (ii) the content of STs in DRMs of chloroplasts does not change under the influence of NaCl; (iii) salinity also causes some elevation in the content of monounsaturated and saturated fatty acids (FAs). Considering the fact that DRMs represent integral parts of both chloroplast and mitochondrial membranes, the authors have come to the conclusion that the cells of euhalophyte S. perennans, under the impact of salinity, presumes the choice (by the cell) of some specific composition of lipids and FAs in the membrane. This may be considered as a specific protection reaction of the plant cell against salinity.

The influence of the physiological and biochemical parameters of the leaves of 12 potato varieties on the formation, plasticity, and stability of the potato crop has been studied. The experiments were carried out on the territory of the Samara Research Institute of Agriculture – branch of the SamSRC RAS (53°03’ N, 49°25’ E) in the period 2019-2022. Average potato yields varied in the range of 14.2-25.7 t/ha. The highest yield was the first planting year. With an increase in the duration of reproduction, yield losses ranged from 25 to 50% due to a decrease in the mass of tubers. The coefficient of variation in yield varied in the range of 24-60% depending on the genotype. Criteria of ecological plasticity and stability of potato of different genetic origin are such indicators as leaf dryness or its hydration, the content of phenolic compounds in the leaves, the content of lipid oxidation products, and the state of the membranes. The amplitudes of variation of leaf indicators can serve as a measure of plasticity. Adaptive capacity is related to the content of proline, the ratio of membrane lipids and proteins, and the number of stomata.

The contribution of the morpho-physiological parameters of leaves and tubers of 22 potato varieties ( Solanum tuberosum L.) to the formation of yield under conditions of insufficient soil moisture and high air temperatures is studied. Discriminant analysis found that the stomata size (12%), chlorophyll content (10%), number of tubers (29%), and average tuber weight (21%) determined the gradation of plants by yield. The specific surface density of leaves (38%), the content of chlorophyll (13%) and carotenoids (13%), and the leaf area (12%) made the greatest contribution to discrimination in relation to ecological plasticity. It is concluded that the number of stomata per unit area of the leaf, the specific surface density of the leaf, and the content of photosynthetic pigments are the key characteristics that contribute to both the high yield and the adaptive capacity of potatoes.

The complex chemical characteristics of leaves of the representative species Globularia punctata were studied. The plant leaves contained large amounts of phenolic compounds (31% of the total analyzed constituents) followed by water-soluble proteins, total lipids, amino acids (AAs), and water-soluble sugars. A total of 22 AAs and two amides were identified with asparagine, glutamine, and proline dominating. An analysis of the lipids showed high concentrations of mono- and digalactosyldiacylglycerols and phosphatidylcholine. The fatty acids were dominated by dienoic and trienoic acids. The main source of linolenic acid was the glycolipid fraction, especially the MGDG and DGDG classes. The phospholipid fraction was more enriched in oleic and linoleic acids. The neutral lipid fraction contained various amounts of linoleic and linolenic acids.

Globularia punctata Lapeyr. (Plantaginaceae) belongs to the ecological-historical group of pliocene relict plants. A distinguishing feature of the relict plant species is specific adaptability to particular habitat conditions (climatic, geomorphological, edaphic, and biological). The goal of the work was to study the structural and functional features of this species and their seasonal variability. We carried out a comprehensive analysis of the structure of the photosynthetic apparatus both at the level of cell morphology and at the level of membrane systems. Globularia punctata retained the viability of assimilation organs throughout the growing period. In winter leaves, the concentration of pigments remained at a high level. Seasonal changes in the leaf mesostructure were associated with changes in the number and size of cells and chloroplasts. The reorganization of the chloroplast ultrastructure due to the thickening of the thylakoids space, an increase in the number of plastoglobules, and intensive expenditure of starch prepared plants to overwintering. The maintenance of homeostasis in both the cell and plastids was provided by changes in the lipid composition and the content of fatty acids.

The mesophyll structure and the lipid profile of membranes were examined in leaves of four Chenopodiaceae halophytes with different types of photosynthesis. The analyzed plants represented the annual species with photosynthesis of C3 type (Salicornia perennans),C3–C4intermediate type (Sedobassia sedoides), and C4-NAD type (Climacoptera crassa) as well as a perennial half-shrub Kochia prostrate with photosynthesis of C4-NADP type; the chosen species inhabited biotopes with various salinity and soil moisture content. The annual species with succulent leaves accumulated 7–15 times larger amounts of Na+ than the perennial half-shrub. A strong positive correlation was found between the leaf thickness and leaf water content (r = 0.98, P = 0.04) and the total amount of elements accumulated in leaves (r = 0.96, P = 0.04). Mesophyll cells of the C3 species S. perennans were substantially larger than the mesophyll and bundle sheath cells of the C4 species; the number of chloroplasts per cell in the C3 species was 1.5–3.5 times higher than in the C4 species. The species with Kranz anatomy differed between one another in terms of the size and the relative number of bundle sheath and mesophyll cells. The total surface area of chloroplasts per unit leaf area in plants with Kranz anatomy was higher in mesophyll cells than in the bundle sheath cells. The assimilating surface areas of mesophyll and chloroplasts in plants with the C3 and C3–C4 types of photosynthesis were similar, as was that in species with C4-NAD and C4-NADP types of photosynthesis. The total number of cells and the number of chloroplasts in mesophyll cells correlated positively with the content of total lipids per unit leaf area (r = 0.95, P = 0.04). The content of 18:2(n-6) fatty acid decreased, while the content of 18:1(n-9) increased in the series C3 → C3–C4 → C4-NAD → C4-NADP species. It is concluded that differences among the examined species in terms of the volume and surface area of cells and chloroplasts in mesophyll and bundle sheath tissues become larger, while the content of membrane lipids in cells, chloroplasts, and mitochondria per unit leaf area decreases along with the extent to which the C4 syndrome is pronounced. The composition of lipids and fatty acids is suited to support the metabolic activity of chloroplasts and mitochondria according to the type of photosynthesis.

Sterols (STs) have a key role in regulating the fluidity and permeability of membranes in plants (phytosterols) that have wide structural diversity. We studied the effect of structural STs diversity on salt tolerance in halophytes. Specifically, we used gas chromatography-mass spectrometry (GC-MS), including two-dimensional gas chromatography-mass spectrometry (GCxGC-MS), to assess the STs composition in leaves of 21 species of wild-growing halophytes from four families (Asteraceae, Chenopodiaceae, Plumbaginaceae, Tamaricaceae) and three ecological groups (Euhalophytes (Eu), recretophytes (Re), salt excluders (Ex)). Fifteen molecular species of STs from three main groups, Δ5-, Δ7-and Δ0- STs (stanols), were detected. Plants of the genus Artemisia were characterized by a high content of stigmasterol (30-49% of the total STs), while β-sitosterol was the major compound in two Limonium spp., where it comprised 84-92% of the total STs. Species of Chenopodiaceae were able to accumulate both Δ5-and Δ7-STs and stanols. The content of the predominant Δ5-STs decreased in the order Ex → Re → Eu. Molecular species with a saturated steroid nucleus were identified in Eu and Re, suggesting their special salt-accumulating and salt-releasing functions. The structural analogues of stigmasterol, having a double bond C-22, were stigmasta-7,22-dien-3β-ol (spinasterol) and stigmast-22-en-3β-ol (Δ7--sitosterol). The ratio of Δ5-stigmasterol/Δ5-β-sitosterol increased in Ex plants, and spinasterol/Δ7--sitosterol and 22-stigmastenol/sitostanol increased in Eu plants. These data support the well-known role of stigmasterol and its isomers in plant responses to abiotic and biotic factors. The variability in STs types and their ratios suggested some involvement of the sterol membrane components in plant adaptation to growth conditions. The balance of Δ5-, Δ7-and stanols, as well as the accumulation of molecular analogues of stigmasterol, was suggested to be associated with salt tolerance of the plant species in this investigation.

Background. One of the important indicators of the nutritional value of amaranth is the high content of protein and lipids in seeds. Hence, obtaining and identifying such forms of amaranth through breeding, so that they also possessed resistance to abiotic stressors, is an important task.Materials and methods. Leaves and seeds of Amaranthus cruentus L. and mutants of the second inbred generation obtained by treatment with sodium azide were analyzed. The Bradford assay was used to measure the content of total soluble protein, lipid analysis was performed by thin-layer chromatography, the state of the antioxidant system was assessed according to catalase and peroxidase activities and the rate of superoxide anion formation. Mathematical data were processed using the Statistica 10.0 software.Results. The highest concentration of total protein in seeds was 13.78 mg/g in one of the mutants obtained after treatment with 3 mM sodium azide. Fifteen fatty acids were found in amaranth seeds, and in four mutants a significant increase in the percentage of omega-6 unsaturated linoleic acid was recorded. An increase in salt tolerance compared to the control was observed in mutants No. 2 and No. 3. Mutant No. 2 under salinization demonstrated higher peroxidase activity and mutant No. 3 higher catalase activity; both mutants showed a reduced rate of superoxide anion formation compared to the control.Conclusion. Amaranth mutants identified for higher stress resistance, protein content and linoleic acid content can be recommended for further breeding to produce new cultivars of amaranth with economically valuable traits.

The aim of the study was to investigate the morphological, physiological, and biochemical parameters of leaves to evaluate the yield of Solanum tuberosum L. We conducted 3-year experiments with 24 varieties of potatoes, differing in ripeness groups (early ripening, mid-early ripening and mid ripening). Plant height, linear dimensions, number of stomata per unit leaf area as well as content of pigments, proline, membrane lipids and proteins, and the level of lipid per oxidation in the leaves of each variety were investigated. A 3D modeling method showed the yield of early varieties negatively correlated with an increase in temperatures (R = –0.97). The soil moisture content positively correlated with the yield of medium-early varieties (R = 0.97). The soil moisture content and the tuber numbers in mid-season varieties had a negative correlation (R = –0.96). The regulation mechanisms of processes in cells depend on the ripening time of a variety. In order to increase productivity and to improve the potato quality, it is necessary to take into account the peculiarities of the regional climatic conditions and use the varieties of a certain ripening group. Our data refine the understanding of the relationship between the potato above-ground mass and the yield of tubers.

Salt stress is one of the most common abiotic kinds of stress. Understanding the key mechanisms of salt tolerance in plants involves the study of halophytes. The effect of salinity was studied in two halophytic annuals of Chenopodiaceae Salicornia perennans Willd. and Climacoptera crassa (Bied.) Botsch. These species are plants with C3 and C4-metabolism, respectively. We performed a comprehensive analysis of the photosynthetic apparatus of these halophyte species at different levels of integration. The C3 species S. perennans showed larger variation in leaf functional traits—both at the level of cell morphology and membrane system (chloroplast envelope and thylakoid). S. perennans also had larger photosynthetic cells, by 10–15 times, and more effective mechanisms of osmoregulation and protecting cells against the toxic effect of Na+. Salinity caused changes in photosynthetic tissues of C. crassa such as an increase of the mesophyll cell surface, the expansion of the interface area between mesophyll and bundle sheath cells, and an increase of the volume of the latter. These functional changes compensated for scarce CO2 supply when salinity increased. Overall, we concluded that these C3 and C4 Chenopodiaceae species demonstrated different responses to salinity, both at the cellular and subcellular levels.