Effect of Selenium and Garlic Extract Treatments of Seed-Addressed Lettuce Plants on Biofortification Level, Seed Productivity and Mature Plant Yield and Quality.

The enhancement of the plant seed yield and quality represents the basis of the successful productivity of the deriving crop. The effect of single and combined foliar treatments of lettuce plants with sodium selenate and garlic bulb extract on seed yield and quality and on mature plant biochemical characteristics was investigated using four lettuce cultivars (Bouquet, Picnic, Moskovsky parnikovy and Cavalier). The seed production of plants treated with Se increased by 20-41%, compared to the untreated control plants, while the augmentation was as much as 10-23% and 17-27% under garlic extract and the joint application of Se and garlic, respectively. Garlic extract stimulated the accumulation of Se in lettuce seeds, which rose by 1.21-1.29 times compared to the Se-treated plants. The proline levels in lettuce seeds exceeded the corresponding values recorded in the control ones by 1.32-1.64 times in the case of the Se supply, 1.10-1.47 times upon garlic extract application and 1.09-1.31 times under the combined Se/garlic treatment. All the treatments given to lettuce plants increased the leaf weight by 1.10-1.30 times, compared to the untreated control. The seed Se levels positively correlated with the leaf weight (r = 0.621; p < 0.005), chlorophyll (r = 0.672, p < 0.002) and total antioxidant activity (AOA; r = 0.730, p < 0.001) of plants grown from these seeds. Positive correlations were also recorded between the seed proline content and lettuce plant leaf weight, chlorophyll and AOA (r = 0.868, 0.811 and 0.815, respectively, at p < 0.001). Lettuce yield was positively correlated with the leaf AOA, chlorophyll and ascorbic acid content (r = 0.942, 0.921 and 0.665, respectively, at p < 0.001). The results indicate high prospects of Na2SeO4 and garlic extract application to seed-addressed lettuce plants, to improve seed productivity and quality, as well as lettuce yield and quality.

The Accumulation of Volatile Compounds and the Change in the Morphology of the Leaf Wax Cover Accompanied the "Anti-Aging" Effect in Anethum graveolens L. Plants Sprayed with 6-Benzylaminopurine.

Essential oils (EOs) are of commercial importance for medicine, food, cosmetics, the perfume industry, and agriculture. In plants, EOs, like the wax cover, serve as protection against abiotic stresses, such as high temperatures and water deficiency. The use of spraying with exogenous hormones of aromatic plants affects the accumulation and composition of volatile compounds, as well as tolerance to abiotic stress. As a result of cytokinin treatment with 6-BAP (6-benzylaminopurine) (200 mg L-l) of Anetum graveolens L. "Uzory" and "Rusich" varieties, several responses to its action were revealed: a change in the division of leaf blades, inhibition of flowering, an increase in the content of EO and its main components α-phellandrene and p-cymene in leaves, and limonene in umbels and fruits. It was revealed that the increased accumulation of EO in dill leaves was longer with sufficient moisture. In contrast, under conditions of heat and water deficiency, the effect of 6-BAP treatment on accumulations of the EO in leaves was short-lived and did not appear on umbels and fruits. The study of the cytokinin effect on a fine structure of a wax cover on the adaxial side of leaves by scanning electron microscopy revealed a change in its elements (from amorphous layers with scales to thin tubules), which probably increased the sensitivity of leaves to water deficiency and, consequently, led to a decrease in the biosynthetic activity of leaf tissue. Thus, 6-BAP had an impact on the adaptive properties of dill plants, prolonging the "youth" of vegetative organs and the ability to EO biosynthesis under conditions of sufficient moisture.

Varietal Differences in Juice, Pomace and Root Biochemical Characteristics of Four Rhubarb (Rheum rhabarbarum L.) Cultivars.

The complex evaluation of varietal biochemical differences in rhubarb juice, pomace and roots is highly useful to develop an efficient processing technology. Research was carried out to compare four rhubarb cultivars (Malakhit, Krupnochereshkovy, Upryamets and Zaryanka) in terms of the quality and antioxidant parameters of juice, pomace and roots. The laboratory analyses showed a high juice yield (75-82%) with a relatively high content of ascorbic acid (125-164 mg L-1) and other organic acids (16-21 g L-1). Citric, oxalic and succinic acids accounted for 98% of the total acids amount. The juice of the cultivar Upryamets demonstrated high levels of the natural preservatives sorbic (36.2 mg L-1) and benzoic acids (11.7 mg L-1), which are highly valuable in juice production. The juice pomace proved to be an excellent source of pectin and dietary fiber, whose concentrations reached 21-24% and 59-64%, respectively. The total antioxidant activity decreased according to the following sequence: root pulp (161-232 mg GAE g-1 d.w.) > root peel (115-170 mg GAE g-1 d.w.) > juice pomace (28.3-34.4 mg GAE g-1 d.w.) > juice (4.4-7.6 mg GAE g-1 f.w.), suggesting that root pulp is a highly valuable antioxidant source. The results of this research highlight the interesting prospects of the complex rhubarb plant processing for the production of juice, containing a wide spectrum of organic acids and natural stabilizers (sorbic and benzoic acids), dietary fiber and pectin (juice pomace) and natural antioxidants (roots).

Iodine and Selenium Biofortification of Chervil Plants Treated with Silicon Nanoparticles.

Production of functional food with high levels of selenium (Se) and iodine (I) obtained via plant biofortification shows significant difficulties due to the complex interaction between the two elements. Taking into account the known beneficial effect of silicon (Si) on plant growth and development, single and joint foliar biofortification of chervil plants with potassium iodide (150 mg L-1) and sodium selenate (10 mg L-1) was carried out in a pot experiment with and without Si nanoparticles foliar supplementation. Compared to control plants, nano-Si (14 mg L-1) increased shoot biomass in all treatments: by 4.8 times with Si; by 2.8 times with I + Si; by 5.6 times with Se + Si; by 4.0 times with I + Se + Si. The correspondent increases in root biomass were 4.5, 8.7, 13.3 and 10.0 times, respectively. The growth stimulation effect of Se, I and I + Se treatments resulted in a 2.7, 3.5 and 3.6 times increase for chervil shoots and 1.6, 3.1 and 8.6 times for roots, respectively. Nano-Si improved I biofortification levels by twice, while I and Se enhanced the plant content of each other. All treatments decreased nitrate levels, compared to control, and increased the photopigment accumulation. Improvement of total antioxidant activity and phenolic content was recorded only under the joint application of Se + I + Si. Foliar nano-Si treatment affected other element content in plants: decreased Na+ accumulation in single and joint supplementation with Se and I, restored Fe, Mn and Cr amount compared to the decreased levels recorded in separately Se and I fortified plants and promoted Al accumulation both with or without Se and I biofortification. The results of this research suggest high prospects of foliar nano-Si supply for enhancing both growth and joint I/Se biofortification of chervil.

Yield, Growth, Quality, Biochemical Characteristics and Elemental Composition of Plant Parts of Celery Leafy, Stalk and Root Types Grown in the Northern Hemisphere.

Celery is one of the major nutraceutical vegetable species due to the high dietary and medicinal properties of all of its plant parts. Yield, growth and produce quality of six celery genotypes belonging to leafy (Elixir and Samurai), stalk (Atlant and Primus) or root (Egor and Dobrynya) types, as well as the distribution of biomass, sugars, mineral elements and antioxidants among the different plant parts, were assessed. Within the celery root type, cultivar Dobrynya resulted in higher yield than Egor, whereas the genotype did not significantly affect the marketable plant part production of leafy and stalk types. Leaf/petiole ratios relevant to biomass, total dissolved solids, sugars, ascorbic acid, flavonoids, antioxidant activity and ash, K, Zn, Fe, Mn, Cu and Se content were significantly affected by the celery type examined. Ash content was highest in the leaves and lowest in the roots. Celery antioxidant system was characterized by highly significant relationships between ascorbic acid, polyphenols, flavonoids, antioxidant activity and Zn. Among the celery types analyzed, the highest values of chlorophyll, Fe and Mn content as well as antioxidant activity were recorded in leaves from root genotypes, which suggests interesting nutraceutical prospects of the aforementioned plant parts for human utilization.