The Vacuolar Transporter OsNRAMP2 Mediates Fe Remobilization During Germination and Affects Cd Distribution to Rice Grain

Background and aims Iron (Fe) deficiency in plants is a common problem affecting agricultural production. Cadmium (Cd) is a toxic metal that can be taken up and transported within plants by transporters for divalent metals including Fe(II). The present study aims to investigate the functions of OsNRAMP2 (Natural Resistance-Associated Macrophage Protein 2) in the remobilization and distribution of Fe and Cd in rice. Methods The expression pattern of OsNRAMP2 was determined by quantitative real-time PCR and pOsNRAMP2:GUS assay. Knockout mutants of OsNRAMP2 were generated by using CRISPR/Cas9 gene editing. Localization of Fe in the vacuolar globoids of germinating seeds was imaged by high-resolution transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy. Distributions of Fe and Cd between different plant tissues were investigated in hydroponic and soil pot experiments. Results OsNRAMP2 was mainly expressed in the embryo of germinating seeds, roots, leaf sheaths and leaf blades. OsNRAMP2 was localized at the tonoplast. Knockout of OsNRAMP2 delayed seed germination and produced chlorotic seedling leaves. Remobilization of Fe stored in the protein storage vacuoles in the scutellum of germinating seeds was restricted in osnramp2 mutants compared with wild type. Expression of genes related to Fe uptake was enhanced in the seedlings of osnramp2 mutants. Knockout of OsNRAMP2 significantly decreased the distribution of Cd, but not Fe, from leaves and straws to rice grains. Conclusions OsNRAMP2 plays an important role in remobilizing vacuolar Fe during seed germination and affects translocation of Cd from vegetative tissues to rice grains.

Productivity of durum wheat cultivars depending on seeding rates in the Chuvash Republic

The results of two-year experimental data on the growth, development and productivity of spring durum wheat cultivars - Bezenchukskaya Niva and Bezenchukskaya Zolotistaya - in the Chuvash Republic were considered. It was found that decrease in the seeding rate of germinating seeds (from 7 to 3 million per 1 ha) resulted in reducing of the growing period in the studied cultivars of spring durum wheat by 6-7 days. Seeding rate of 5 million seeds per 1 ha provided the maximum density of spike-bearing stems due to the best indicators of general and productive tillering. The formation of the largest main spike with a high grain content in Bezenchukskaya Niva cultivar was noted at the seeding rate from 3 to 5 million seeds per 1 ha. Increase in the seeding rate ( 5 million seeds) led to a decrease in the parameters of the main spike. Analysis of Bezenchukskaya Zolotistaya yield structure did not reveal clear patterns in the change in length and grain size of the main spike resulted from the seeding rate. However, the highest 1000-seed weight (50.4 g) was obtained in the variant with a seeding rate of 6 million seeds pieces. Compared to the control, the maximum yield increase in cv. Bezenchukskaya Niva (1.2 t/ha) was obtained in the variant with a seeding rate of 5 million seeds per 1 ha. The highest yield of cv. Bezenchukskaya Zolotistaya (3.23 t/ha) was obtained at a seeding rate of 6 million seeds per 1 ha.

Influence of methods and norms of sowing soybean seeds of the Northern ecotype on yield

The article presents the results of studying the optimal norms and methods of sowing a new variety of soybeans of the northern ecotype of the Memory of Fadeev for 2016-2018 at the experimental site of the Chuvash Research Agricultural Institute-a branch of the Federal State Budgetary Institution “Federal Agricultural Research Center of the North-East named after N V Rudnitsky” in the southern part of the Volga-Vyatka region of Russia. It is established that in order to obtain high yields of soybean seeds of the northern ecotype in the conditions of the Chuvash Republic, the ultra-ripe variety of soy in Memory of Fadeev should be sown in a wide-row way at a rate of 600 thousand germinating seeds per 1 ha. It is revealed that to obtain a higher attachment of the lower bean, narrow-row sowing is recommended - the height of the attachment increases to 17.3 cm. Wide-row sowing increases the number of beans, the number and weight of seeds per plant, as well as the weight of 1000 seeds, which leads to an additional yield of up to 6.8 c/ha. According to the data obtained, an agroecological passport has been developed for a new Chuvash soybean variety of the northern ecotype of the Fadeev Memory variety, zoned in 2019.

Formation of plants density and seed yield of soybean varieties in Altai Krai

Relevance. Soybean (Glycine max (L.) Merrill is one of the most important protein- oilseed crops in world arable farming. An acute shortage of both food and feed protein is felt in many world’s countries. In this regard, the expansion of soybean seed production is relevant and is dictated by the need for import substitution of both food and feed soybean products.Materials and methods. In the research we studied the influence of two ecologically different cultivation zones: Priobskaya and Prialtaiskaya on the formation of plants density and seed yield of soybean. Three varieties Altom, Gratsia and Pripyat were taken as the objects of the research.Results. On average, over the years of research in full seedlings stage from 60 germinating seeds per square meter (600 thousand pieces/ha), in our experiment, about 56 plants were obtained per 1 m2 or 560 thousand plants per 1 hectare. This means that, on average, 93% of sown seeds give seedlings in field conditions. For harvesting after exposure of soybean crops to numerous biotic and abiotic factors, on average, there are about 52 plants per 1 m² or 520 thousand plants per 1 hectare, that is, 88% of the sown germinating seeds are saved for harvesting and give a yield. The maximum influence on the variability of plant density is exerted by vegetation conditions (years) – 37%. On average, over the years of the study, the maximum yield under Topchikha conditions was obtained in 2019 – 1.9 t/ha – in a year that was distinguished by not hot weather with sufficient rainfall during the growing season. Varieties Gratsia and Pripyat in Smolenskoye conditions significantly exceeded the standard in terms of yield in 2018 and 2020. On average, over the years of research, the Gratsia variety showed itself as more stable with Cv=11.3% in Topchikha conditions and Cv=9.8% in Smolenskoye conditions.

Spring vetch Mega mixed crops productivity at different seeding rates

Spring vetch is the most well-known annual legume forage crop. With the cultivation and application of various methods and terms of harvesting crops, not only for green fodder and hay, but also for haylage, silage, grain-growing, the requirements for the quality of the mown mass were reduced, but the need to create non-growing crops suitable for machine harvesting increased. In the gene pool of spring vetch, there are no forms with a strong, resistant to lodging stem, so the only way to solve the problem is to support the supporting culture. According to the results of research for two years, for the cultivation of vetch for green mass, the best option is vetch mixed with oats with a seeding rate of 1.2 million vetch, oats of 3 million germinating seeds per hectare. For grain cultivation, the best option is a mixture of vetch and oats with a seeding rate of 1.8 million and 3 million germinating seeds, respectively. For obtaining a grain crop for seed-growing purposes, the best option for two years of research is vetch mixed with spring wheat with a seeding rate of 1.8 and 3 million germinating seeds per hectare.

Parameters of the optimal plant density of winter rape for successful overwintering in the Non-Chernozem zone

To obtain high yields of winter rapeseed seeds in the Non-Chernozem zone, it is necessary to provide conditions for good wintering. The studies were carried out in order to establish the optimal plant density of the zoned variety Severyanin. It was found that when sowing in rows with a row spacing of 25 cm, winter rape plants develop better, form a rosette of leaves with a lower location of the growing point, form a smaller amount of aboveground mass per unit of roots, which increases the safety of plants in winter by 2.5-4.3%. period under extreme conditions. The study of the dynamics of the plant density of winter rapeseed at different seeding rates showed that during the growing season, self-thinning of cenosis occurs. On average, over the years of research, plants overwintered better in variants with a lower stand density. With an increase in the seeding rate, the completeness of seedlings, the safety of plants in the autumn period, overwintering and the safety of plants in the year of harvesting for seeds decreased. The most optimal conditions for the preservation of plants for harvesting are provided at low seeding rates: with a row sowing with a row spacing of 25 cm with a seeding rate of 0.7-1.0 million pieces / ha, with an inter-row sowing (row spacing of 25 cm) - 0.5 million pcs / ha of germinating seeds: With the over-row sowing, the safety of plants for harvesting was higher than with the row method by 9-25%.

Growth stimulators and mineral fertilizers influence on Sudan grass growth, development and productivity

The article considers the results of research on the influence of seeding rates, fertilizers and growth stimulator on the development and productivity of the Sudan grass of the Julia variety in the conditions of chestnut soils of the Volgograd region. In the field two-factor experiment, we studied: factor A - the three seeding rates 1.0, 1.5 and 2.0 million germinating seeds per hectare; factor B - fertilizers and growth promoters: 1. Control without fertilizers; 2. N60 P60 K45 + N30; 3. Growth stimulator Raikat Start; 4. N60 P60 K45 + Raikat Start + N30. The use of mineral fertilizers increased the leaf surface area by 0.3-0.5 thousand m2/ha, the use of growth stimulators increased the leaf surface area by 0.1-0.2 thousand m2/ha, the combined use of mineral fertilizers and growth stimulators increased the leaf surface area by 0.9-1.2 thousand m2/ha. It was found that the highest yield of green mass of Sudan grass, 28.6 t/ha, was formed on the variant with a seeding norm of 1.5 million tons of germinating seeds per ha with the complex application of mineral fertilizers and the growth stimulator Raikat Start.

The influence of synthetic foaming agents on seed germination of coniferous species

Water is the most frequently used substance for extinguishing of wildfires. Ones of the most commonly used additives enhancing the extinguishing efficiency are foaming agents. This article deals with the influence of foaming agents on germination of coniferous species. Foaming agents Moussol-APS F-15 and Sthamex F-15, foaming solutions of various concentrations were used for the tests. Germination of seeds of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) was observed. The percentage of germinating seeds was recorded every 7 days. The results were evaluated in the form of graphs. When the concentration levels of foaming solutions ranged from 0.1 vol% to 0.25 vol%, their influence on germination of both coniferous species seeds varied from negligible to slightly positive. Subsequently, the negative effect increased considerably and with concentrations exceeding 1 vol% - 1.5 vol% the germination of samples reached zero values. While foaming solutions of Sthamex F-15 showed less significant influence on germination of the Scots pine seeds, seeds of the Norway spruce were less influenced by foaming agent Moussol-APS F-15. Based on obtained results it is possible to recommend minimisation of foaming agents amounts, eventually application of substances with less negative effect on plants germination for extinguishing of wildland fires, in order to gain restoration of affected area as fast as possible. Key words: foaming agent, germination, wildfire (wildland fire), foaming solution

Exogenous Spermidine Priming Mitigates the Osmotic Damage in Germinating Seeds of Leymus chinensis Under Salt-Alkali Stress

Spermidine (Spd) is known to protect macromolecules involved in physiological and biochemical processes in plants. However, it is possible that Spd also plays an osmotic regulatory role in promoting the seed germination of Leymus chinensis (L. chinensis) under salt-alkali stress. To investigate this further, seeds of L. chinensis were soaked in Spd solution or distilled water, and a culture experiment was performed by sowing the soaked seeds in saline-alkaline soils. The data showed that the Spd priming resulted in an increase of more than 50% in soluble sugar content and an increase of more than 30% in proline content in the germinating seeds. In addition, the Spd priming resulted in an increase of more than 30% in catalase activity and an increase of more than 25% in peroxidase activity in the germinating seeds and effectively mitigated the oxidative damage to the plasma membrane in the germinating seeds under salt-alkali stress. Moreover, the Spd priming of seeds affected the accumulation of polyamine (PA) and maintained the activities of macromolecules involved in physiological metabolism in germinating seeds exposed to salt-alkali stress. Furthermore, the Spd priming treatment increased the hydrogen peroxide (H2O2) level to more than 30% and the Ca2+ concentration to more than 20% in the germinating seeds, thus breaking the dormancy induction pathways in L. chinensis seeds through beneficial hormone enrichment. This study provides an insight into the Spd-mediated regulation pathway during exogenous Spd priming of L. chinensis seeds, which mitigates osmotic and oxidative damage and maintains the integrality of the cell lipid membrane. Thus, exogenous Spd priming increases PA oxidase activity and maintains the accumulation of H2O2. We found that the H2O2 beneficially affected the balance of Ca2+ and hormones, promoting the vigor and germination of L. chinensis in response to salt-alkali stress.

Acceleration in Germination Sensu stricto Plays a Central Role on Seedling Vigor in Post-Germination

An obvious relationship between germination sensu stricto and seedling development during post-germination has been considered, but not explained concerning vigor. Taking this into account, we used measurements of water dynamics in germinating seeds and seedling development to clarify that relationship. The biological model was soybean seeds, since it is the most relevant ‘true seed’ produced around world. Our findings suggest that the way energy is used (acceleration) and not its input (velocity) is the main aspect relating seed germination and seedling development, especially when considering vigor. However, velocity and acceleration can be complementary in analyses of seed physiology. Other measurements proposed here also have potential uses for testing vigor in seed lots, such as seedling vigor index and biological activity in the lot. Therefore, water dynamics in germinating seeds can be an interesting way for testing seed lots, because it is an easier, faster and cheaper method in relation to other non-destructive procedures.