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In global climate change, drought stress is one of the environmental restraining factors that can significantly influence the growth and development of crop plants. Drought stress conditions can also cause undesirable changes in plant physiological and metabolic processes. The influence of soil drought on the mineral composition of leaves and seeds of two species of amaranth (Amaranthus tricolor L. and Amaranthus cruentus L.) with C4-type of photosynthesis was studied through energy dispersive spectrometry (ESD). The recent investigations were carried out during the years 2020-2022 at the Department of Genofonde and Bioresources of Plants, Federal Scientific Center for Horticulture, Moscow, Russia. The research results showed the leaves of both amaranth with major elements, i.e., K (11.23-15.33), Ca (5.15-7.61), P (3.91-3.92), Mg (2.81-3.36), and Cl (1.86-2.29), whereas, relatively lower values were recorded for Fe (0.05-0.48), and Na (0.07-0.11) mass% respectively. Regarding amaranth plants seed composition, the major elements were K (13.86-13.97), P (7.02-9.76), Mg (3.78-5.64), Ca (3.31-4.78), Cl (2.81-5.30), and Mo (2.80-2.86) mass% respectively. In the species, A. tricolor, a strong correlation was observed between the elements, i.e., S-Cu, Mg-Si, Na-Cu, Na-S, Na-Ca, Na-Si, and Si-S in leaves, while in seeds, these were between Ca-Cu, Mg-Cl, Si-Mn, Ca-Mo, and Cl-Mn. In the other species of amaranth, A. cruentus, the elements viz., Mg-S, Mg-Mo, S-Mo, Mg-Cl, S-Cl, Cl-Mo, Cl-P, P-S, Si-Cl, Ca-Mo, S-Ca, Mg-Ca, Mg-P, P-Mo, and Mg-Si in leaves, while Ni-Cu, Mg-P, Si-P, and Si-Cl in seeds also showed strong relationship. Effects of drought led to a weakening of these ties and the formation of new ones. The accumulation of mineral elements in the leaves of amaranth plants varies from species to species under drought conditions, and A. tricolor cv. Valentina was found most resistant to drought conditions. [ABSTRACT FROM AUTHOR]

This research aimed to study the leaf micromorphological and biochemical features of columnar apple cultivars that are immune and moderately resistant to Venturia inaequalis, the causal agent of scab disease, during 2017-19 at the Federal Horticultural Research Center for Breeding, Agrotechnology, and Nursery, Moscow, Russia. Results revealed that the immune cultivars showed a higher level of adaptability to the fungus V. inaequalis than the moderately resistant cultivars. The large number of leaf trichomes on the abaxial leaf surface that confer protection was characteristic of the immune cultivars. The immune columnar apple cultivars had 6% fewer leaf stomata than the moderately resistant ones. The stomata of the immune cultivars were placed high in the leaf surface, were surrounded by chords and folds, and had high cuticular peristomatal rings that provided additional protection by preventing pathogen entry. Inclusions with parallelogram and rounded-star shapes were found in the cross-section cut of the central leaf midrib of the immune cultivars. By contrast, the inclusions were mostly rounded-star-shaped in moderately resistant cultivars. Analysis through electronic microscopy with energy dispersion spectrometry revealed that the Ca and K contents in the parallelogram-shaped inclusions were 3 and 2 times higher than those in the rounded-star-shaped inclusions, respectively. In terms of ash composition, the P, Mg, and Ca contents in the leaves of immune columnar apple cultivars were 1.5, 1.5, and 1.6 times higher than those in the leaves of moderately resistant cultivars. The ultrafine surface study was more reasonable than other methods for identifying the phytopathogen resistance of fruit trees. The use of modern instrumental analytical methods for the complex evaluation of fruit crop leaves to reveal adaptations to biotic factors is meaningful for breeding use. [ABSTRACT FROM AUTHOR]

Drought is one of the limiting factors affecting the environment worldwide. It adversely affects crop plant growth and development. The stressful effects of arid conditions cause changes in the morphological traits and physiological processes of plants. This study, photosynthetic pigment contents, photosynthetic system 2 (PS2) activity, antioxidant activity, and total phenolic compound (TPC) amounts were determined in the leaf extracts of two species of amaranth (with C4-type photosynthesis), namely, Amaranthus tricolor L. cultivar 'Valentina' and Amaranthus cruentus L. cultivar 'Krepysh'. The same parameters were determined in two species of actinidia (with C3-type photosynthesis), specifically, Actinidia arguta cultivar 'Taezhny Dar' and Actinidia kolomikta cultivar 'Narodnaya'. All parameters were measured before and after drought stress. The seedlings were initially grown in the laboratory, then planted in separate pots and kept in the greenhouse under a canopy to protect them from the rain. Chlorophyll (Chl) a and b, carotenoids, antioxidant activity, and phenolic compound contents were determined spectrophotometrically. PS2 activity was determined by using pulse amplitude modulation fluorometry. The functional state of PS2 was more resistant to water deficiency and drought in amaranth than in actinidia species. Certain differences were established in the resistance of PS2 to dehydration between the two species of amaranth under drought conditions, and the highest Chl fluorescence indexes were characterized in the tricolor amaranth cultivar 'Valentina'. Car content was 6.5 times higher in the leaves of A. arguta and 2.5 times higher in the leaves of A. kolomikta than in the leaves of the control plants. The highest correlation was found between Chl a and Car (r = 0.985) and Chl b and Car (r = 0.977) in the leaves of both species of amaranth. Under moisture deficit conditions, the antioxidant activity of water and alcohol extracts in the leaves of both species of amaranth increased from 1.5 time to 2.5 times. A high correlation (r = 0.77, r = 0.91) was found between the antioxidant activity of the water and alcoholic extracts and the TPC in the leaves of both amaranth species, respectively. [ABSTRACT FROM AUTHOR]

A recent study in 2019-2020 assessed the productivity, the quality of fatty and essential oils, and the mineral composition of eight nigella genotypes at the Federal State Budget Scientific Institution (FSBSI), Research Institute of Agriculture of Crimea, Simferopol, Russia. Of the eight genotypes, two cultivars originated from Crimea, Russia (Nigella sativa cv. 'Krymchanka,' and Nigella damascena cv. 'Yalita'), and one each from six European-Asian countries, i.e., Dagestan, Uzbekistan, and Sweden (Nigella sativa), Pakistan and India (Nigella indica), and Belgium (Nigella damascena). The Russian nigella genotypes served as control. Genotypes from three European-Asian countries (Sweden, Pakistan, and Dagestan) distinguished from the rest by their highest seed productivity, i.e., 1.0-1.6 g plant-1, which was 1.7-2.7 times higher than the control cultivar 'Krymchanka.' The seed productivity of the genotype N. damascena cv. 'Yalita' control was 1.5 times greater than the nigella genotype from Belgium. The N. indica produced the highest fatty oil content (29.9%), which exceeded two other species, i.e., N. sativa and N. damascena by 16%-22%. Fatty oils of nigella also contained essential oils of 0.5% for N. sativa and 1.2% for N. damascena. The essential oil of N. sativa contained dominant components, such as, p-cymene (53.5%) and thymoquinone (19.2%), while N. damascena contained p-cymol (82.2%) and other principal components. The identified samples with the maximum accumulation of fatty and essential oils, and macro and microelements can be used to treat and replenish the deficient elements in the human body. Nigella genotype samples exhibited high accumulation of microelements, viz., potassium, calcium, manganese, iron, copper, zinc, and molybdenum in the leaves and seeds. [ABSTRACT FROM AUTHOR]

Allium cepa L. genotypes with different ecogeographical origins revealed the highest nutritional values when grown in Crimea, Russia. However, their environmental adaptation should be further investigated. This research was performed during 2016–17 to evaluate the qualitative, antioxidant, and mineral composition characteristics of 15 onion genotypes, of which four originated from the Federal State Budget Scientific Institution, Research Institute of Agriculture, Crimea, Russia. Sweet onion genotypes exhibited high ascorbic acid contents of 11.8–27.3 mg/100 g. However, some genotypes had a narrow range of ascorbic acid content (11.8–21.1 mg/100 g) due to their different ecogeographical origins and proved to be appropriate for industrial processing because of their spicy taste. Intensely colored bulbs had a high content of polyphenols (anthocyanins), which are known to have a positive influence on human health. Electronic microscopic assays revealed the morphological characteristics of A. cepa L. genotype leaves and demonstrated the differences in epidermal structure and adaptability potential. The 12 main mineral macro- and microelements with the highest contents in onion leaves were analyzed. The hyperaccumulator genotype with the highest leaf macro- and microelement content could be used to address mineral element deficiencies in humans. In onion genotype leaves, the contents of the mineral elements followed the order of Zn > Fe > Si > Na > Р > Cl > Mo > Mg > S > Ca > Cu > K. The biochemical analysis of 13 onion cultivars showed that the majority exceeded the standard values of dry matter and sugars (mono- and disaccharides) by 13% and 46%, 11% and 48%, and 36% and 150%. In onion genotypes, leaf surface microstructure was specific, and the largest stomata corresponded to the most productive cultivars. [ABSTRACT FROM AUTHOR]