Branched Root System Research Articles

Agrotechnical practices for improving the quality of seed stocks in the nursery

The paper presents the preliminary results of an assessment of some agrotechnical techniques for improving the quality of seed stocks for pears based on quince of ordinary VNIISPK breeding. Studies have shown that the use of bedding material introduced into rows during sowing in the form of sphagnum moss or sand contributed to better branching of the primary root of the seedling, and, consequently, the formation of more skeletal roots than in control variants. The morphological structure of the sand favored high aeration and waterproofing with excess moisture in the root zone of the germinating seed. The skeletal root branched better than in the control. However, the main amount of branching was concentrated on the endings of the skeletal root or close to it. The places of branching of skeletal roots from the main root of the seedling often remained open, which subsequently may lead to a decrease in the anchoring of graft-rootstock combinations in the garden. On the other hand, having a high moisture-retaining ability, aeration and antiseptic properties, sphagnum moss had an even more beneficial effect on the young sprout and subsequently contributes to the formation of a branched root system of the seedling with many overgrown roots. The number of skeletal roots and the order of their branching exceeded the control variants by 1.5–2.0 times. Almost the entire skeletal root branched, which is very valuable for survival, plant fixation in the soil, nutrition and moisture supply during the growing season. Based on the conducted research, in order to improve the quality of seed stocks based on quince, when sowing, bedding material in the form of sand or sphagnum moss should be added to the rows, contributing to better branching of the roots of quince seedlings.

Study on the influence of sideration on soil density and porosity

It was achieved to improve agro physical properties of soil by forming of 22.41-52.92 t/ha green biomass of pea, chickpea, rape and barley when sown as green manure as well as tilling it into soil in summer July 10 wheat freed areas, and autumn October 10 cotton freed areas. It was determined that the mass of soil before the first irrigation of cotton in 0-20 cm tilling layer of soil with green manure applied variant was 0.06-0.08 g/cm3; 0.03-0.08 g/cm3 and it was less 0.05-0.07 g/cm3; 0.03-0.08 g/cm3 in 20-40 cm of soil layer relatively to control-without green manure variants. In its turn, it creates best and favorable condition of branching root system of cotton-plant and will be achieved to get high and quality yield.

Growth rates and nutrient accumulation in aerial biomass of sunn hemp juncea and spectabilis sown in spring

Crotalaria juncea and spectabilis have been widely used in green manuring, mainly due to the fact that they incorporate large amounts of N into the soil, through biological fixation of atmospheric N2, and also because they have a vigorous and branched root system, characteristics that help to recycle nutrients from the deeper layers of the soil. The present work was carried out in the municipality of Mercês, in the Mata Mineira area. Growth rates and nutrient accumulation were evaluated in the aerial part of sunn hemp and sunn hemp, grown in soil with good nutrient availability. The soil in the chosen area had good fertility, with no exchangeable aluminum in the 0 to 20 cm layer. Soon after the first spring rains, the soil was subsoiled, plowed, and harrowed, and the study was then installed, conducted in an experimental design in randomized blocks with five replications. The plots consisted of six furrows of five meters in length with 0.50 meters of spacing. Sowing was carried out in the first week of October. Evaluations of dry matter accumulation and plant height were carried out in the four central furrows of the plots, at 30; 45; 60; 75; 90 and 105 days after emergence (D.A.E.), with a sample area of 1.0 m of furrow (0.5 m2). In the biomass collected at 105 D.A.E, phenological stage of grain filling, the contents of nitrogen, phosphorus, potassium, calcium, magnesium and sulfur were determined, with the objective of quantifying the accumulation of these elements in the aerial part of sunn hemp. The results obtained in this edaphoclimatic environment led to the conclusion that sunn hemp juncea had faster vegetative development than sunn hemp spectabilis, therefore, a plant with greater soil protection potential against the impact of raindrops than sunn hemp spectabilis. Although they have very different growth rates, both for sunn hemp and sunn hemp, the highest rates of growth and dry matter accumulation in the shoots occurred in the periods from 45 to 60 D.A.E., with mean values, respectively, of 406, 7 and 140.0 kg per hectare per day. The accumulation of dry matter in the aerial part, as a function of the age of the plants, can be described by the quadratic equation, y = 0.0024 x2 + 0.5267x -11.8086 (R2= 0.9888), for sunn hemp, and y = 0.0008 x2 + 0.2003x -4.4657 (R2= 0.9928), for sunn hemp spectabilis. For the adopted production system, and in this climatic environment, sunn hemp was a better recycled/fixing plant than sunn hemp spectabilis, thus, green manuring with sunn hemp was more advantageous than with sunn hemp spectabilis.

Phenotypic variation of root-system architecture under high P and low P conditions in potato (Solanum tuberosum L.)

BackgroundPhosphorus (P) is an essential macronutrient required for plant metabolism and growth. Its acquisition by plants depends on the availability of dissolved P in the rhizosphere and on the characteristics of P uptake mechanisms such as root-system architecture (RSA). Compared to other crops, potato (Solanum tuberosum L.) has a relatively poor P acquisition efficiency. This is mainly due to its shallow and sparsely branched root system, resulting in a rather limited exploitable soil volume. Information about potato genotypes with RSA traits suitable to improve adaptation to nutrient scarcity is quite rare. Aim of this study is to assess phenotypic variation of RSA in a potato diversity set and its reactions to P deficiency.ResultsOnly one out of 22 RSA-traits showed a significant increase under low-P conditions. This indicates an overall negative effect of P scarcity on potato root growth. Differences among genotypes, however, were statistically significant for 21 traits, revealing a high variability in potato RSA. Using a principal component analysis (PCA), we were able to classify genotypes into three groups with regard to their root-system size. Genotypes with both small and large root systems reacted to low-P conditions by in- or decreasing their relative root-system size to medium, whereas genotypes with an intermediate root system size showed little to no changes.ConclusionsWe observed a huge variation in both the potato root system itself and its adaptation to P deficiency. This may enable the selection of potato genotypes with an improved root-zone exploitation. Eventually, these could be utilized to develop new cultivars adapted to low-P environments with better resource-use efficiencies.

Эспарцет (Onobrychis Adans .): выгодная культура в органическом лугопастбищном хозяйстве (обзор )

Perennial legumes are the most beneficial crops in the organic grassland farming. These crops include sainfoin, which should take its rightful place in forage lands, especially in modern conditions of increasing aridity. Three species are cultivated in Russia: Onobrychis viciifolia Scop., O. arenaria (Kit.) DC and O. transcaucasica Grossh. The cultivation of sainfoin is of great ecological importance due to its special ecological properties and chemical composition. It has a deep and highly branched root system, capable of absorbing nutrients from deep soil layers. The root system of sainfoin absorbs minerals from hard-to-reach soil compounds, so it is little responsive to fertilisation, and can be successfully used in organic grassland farming. Unlike other leguminous grasses, with the exception of the birdsfoot trefoil, sainfoin does not cause bloat in ruminants. This is due to the presence of condensed tannins (CTs) in the plant in the amount of 30–80 g per 1 kg of dry matter. СТs increase the amount of non-degradable protein in the rumen, which prevents bloat in ruminants, reduces methane emissions and nitrogen compounds in urine, which in turn reduces the impact of greenhouse gases on the heat balance of the Earth. СТs have shown in vivo anti-parasitic activity against helminths in sheep and goats, improving feed nutrient utilisation and increasing animal productivity. Sainfoin fixes atmospheric nitrogen in an amount up to 150 kg/ha and does not require the application of nitrogen fertilisers, which can pollute groundwater and atmospheric air. Enriching the soil with nitrogen and other nutrients due to their biological accumulation in the upper soil layer, sainfoin contributes to soil fertility. sainfoin provides yields from 4 to 7 t/ha of dry matter with a productive longevity of herbage for 4–7 years reducing the cost of reseeding.

Identification and function of miRNA-mRNA interaction pairs during lateral root development of hemi-parasitic Santalum album L. seedlings

Sandalwood (Santalum album L.) is a hemi-parasitic tree species famous for its santalol and santalene, which are extracted from its heartwood and roots. The ability to understand root functionality within its branched root system would benefit the regulation of sandalwood growth and enhance the commercial value of sandalwood. Phenotypic and anatomical evidence in this study indicated that seed germination stage 4 (SG4) seemed pivotal for lateral root (LR) morphogenesis. Small RNA (sRNA) high-throughput sequencing of root tissues at three sub-stages of SG4 (lateral root primordia initiation (LRPI), lateral root primordia development (LRPD), and lateral root primordia emergence (LRPE)) was performed to identify microRNAs (miRNAs) associated with LR development. A total of 135 miRNAs, including 70 differentially expressed miRNAs (DEMs), were screened. Ten DEMs were selected to investigate transcript abundance in different organs or developmental stages. Among 100 negative DEM-mRNA interaction pairs, four targets (Sa-miR166m_2, 408d, 858a, and novel_Sa-miR8) were selected for studying cleavage sites by 5′ RLM-RACE validation. The expression mode of the four miRNA-mRNA pairs was investigated after indole-3-acetic acid (IAA) treatment. IAA enhanced the abundance of homeobox-leucine-zipper protein 32 (HOX32), laccase 12 (LAC12), myeloblastosis86 (MYB86), and pectin methylesterase inhibitor6 (PMEI6) target transcripts by reducing the expression of Sa-miR166m_2, 408d, 858a, and novel_Sa-miR8 in the first 10 min. A schematic model of miRNA-regulated LR development is proposed for this hemi-parasitic species. This novel genetic information for improving sandalwood root growth and development may allow for the cultivation of fast-growing and high-yielding plantations.

Floristic diversity and scientific monitoring of landscapes lower Sula river (border areas of Nyzhnosulskyi National Nature Park)

The paper analyzes the floristic diversity of certain adjacent areas of the border zone of the Nyzhnosulskyi National Nature Park. The obtained new data made it possible to determine the ecological state of the meadow-steppe landscape, as well as the possible use of disturbed lands bordering the buffer zone. The necessity of introducing a protective zone of the National Nature Park has been proven. This will allow to timely assess the ecological state of landscapes; to prevent negative consequences for the protected areas, and in the future to include them in the composition of the protected territory. The conducted studies of floristic diversity and monitoring of disturbed lands in the southern border zones of the Nyzhnosulskyi National Park made it possible to state that there are threats of salinization, impoverishment of floristic diversity, and soil degradation for the southern border area under conditions of increased anthropogenic load or resumption of agricultural operations. It has been established that rare and red-listed plants within the landscape complex “Ivanivski Ozera”, which are also known within the National Nature Park “Nyzhnosulskyi”, have disappeared under the influence of mechanical and chemical intervention by farmers. Some halophytes and other steppe plants with deep or branched root systems remained. Taking into account the peculiarities of the relief of the territory of the Ivanivskі Lakes, the aridization of the climate and the speed of soil salinization processes in the lower Sula within the Obolon depression and under the conditions of further ploughing of the land, the territory will turn into salt marshes. The area of soil salinization will extend to the territory of the Park, which will lead to irreversible changes in the phytocoenosis and the appearance of salt marshes and an even greater number of halophytes. Scientific monitoring of the disturbed lands of the border zone of the nature reserve confirms that for the preservation and protection of floodplain complexes of the Sula River and meadow-swamp ecosystems, it is necessary to provide systematic research and a timely forecast of ecological changes in landscapes; prevention and elimination of negative consequences for protected floristic areas. In addition, it is advisable to include the lands of the buffer zone as part of the protected area of the National Nature Park and determine the degree of effectiveness of measures aimed at the preservation and restoration of land resources.

Substrates based on composted sewage sludge for land recultivation

Increasing a large amounts of sewage sludge in Ukraine is an urgent environmental problem that requires the selection of an effective strategy for their disposal. The usage of sludge composting technology leads to the restoration of sludge as a resource and is cost-effective and environmentally sustainable compared to the method of landfilling. The purpose of this research is to carry out bioindication tests of growth substrates based on composted sewage sludge with the subsequent possibility of their usage in the technology of recultivation of landfills for municipal solid waste. The experiment was performed on four types of compost with different modifications of the natural sorbent - zeolite. During the experiment the average percentage of germination of polygamous ryegrass plants (Lolium perenne L.) was determined in the investigated substrates. The mass and length of the aboveground part of the plant and roots were also measured. The results showed that the addition of natural sorbent to substrates has a positive effect on growth and development of plants. This investigation was conducted in accordance with the current norms of national standards of Ukraine: DSTU 7369 (2013), "Wastewater. Requirements for wastewater and its sediments for irrigation and fertilization"; DSTU ISO 11269-1 (2004), "Soil quality. Determination of the effect of pollutants on soil flora. Part 1: Method for determining the inhibitory effect on a root growth"; DSTU ISO 11269-2 (2002), "Soil quality. Determination of the effect of pollutants on soil flora. Part 2: Effects of Chemicals on Germination and Growth of Higher Plants". The experiment was conducted on four types of compost with different modifications of the natural sorbent - zeolite in percentage amounts: 0; 2.5; 5; 7.5, dark-grey gilded soil was used as a control element. In the experiment, the average percentage of germination of polygamous ryegrass plants (Lolium perenne L.) on the studied substrates was determined. The mass and length of the aboveground part of the plant and roots were also measured. The first sprouts of ryegrass began to appear on the 7th day of the experiment. The highest average value on the seventh day of germination was 90% in the control sample with 5% of sorbent content and in K2 substrate in the sample with 7.5% sorbent content. However, the germination of plants in substrates K3 and K4 occurred later compared with substrates K1, K2, and control. For substrate K1 in the sample with a sorbent content of 5%, plant germination was the highest and was 100%. The highest average value of ryegrass stem length is observed in variant K4 in the sample with 0% zeolite content and in variant K1 in the sample without zeolite content the lowest average value of stem length was observed. The K3 and K4 variants have a more developed root system compared to other variants. Based on the obtained data it can be assumed that the most optimal universal component for creating a growth substrate is variant K3 (mixture of "newly picked" and "old" SS) which has not so developed aboveground part but has very branched root system that allows to adapt to various environmental factors and in combination with a small proportion of natural sorbents can be effective for the recultivation of MSW landfills, which in its turn minimizes the need to use a fertile soil layer.

ВПЛИВ РЕГУЛЯТОРІВ РОСТУ НА РІСТ І РОЗВИТОК РОСЛИН СОНЯШНИКУ В ПІВНІЧНОМУ СТЕПУ УКРАЇНИ

Topicality. In addition to mineral and organic fertilizers, microfertilizers and plant growth regulators should be used more widely to eliminate negative factors (excessive man-made load, deterioration of water, nutrient regimes and soil humus condition) and to improve the sunflower nutrition system. Issues. Growth regulators intensify the development of the leaf surface, activate the basic life functions of sunflower plants: membrane processes, cell division, respiration and nutrition, enzyme systems activity, photosynthesis, and create a branched root system with enhanced absorption capacity. Purpose. To study the influence of growth regulators with different action on the morphogenesis, sunflower growth and development and productivity of different maturity groups in the Northern Steppe of Ukraine. Materials and methods. The field trials were established and carried out in accordance with generally accepted methods of research.. The experimental part of the work was performed during 2018–2020 in the research field of the National Research Center at the Dnipro State Agrarian and Economic University in the stationary experiment of the Crop Production Department in five-field crop rotation: clean fallow – winter wheat – maize – barley – sunflower. Spraying sunflower plants with growth regulators Vympel K-2 (0.7 l/ha), Architect (0.5 l/ha) and Ce-ron (0.5 l/ha) was carried out in the 6–8th pair of leaves stage. Results. When the growth regulators were applied, plant height of sunflower reduced, but such indicators as leaf surface area, chlorophyll content in the leaves, head diameter and number of seeds per head, thousand seed weight, seed yield and quality increased. y. Conclusions. The maximum leaf surface area of sunflower (up to 70.9–78.1 thousand mІ/ha, or 5.5 –10.2 % more than the control) was observed when growth regulator Ceron was applied at the dose of 0.5 l/ha. In this case, sunflower plants formed the largest heads with diameter of 23–26 cm (11.5–30.4 % more than the control), and the maximum number of seeds per head was 863–925.3 pieces that exceeded the control by 3, 4–5.6 %. The highest thousand seed weight (54.0–60.0 g) was for the mid-early hybrid Sumico HTS, and the lowest (51–55 g) – for the mid-late Subaro HTS that is explained by the biological characteristics of the hybrids. The crop yield increased by 1.05–1.17 times due to the application on sunflower of plant growth regulators. The largest increase in grain yield for all hybrids (0.22–0.27 t/ha, or 13.5–14.8 %) was provided with Ceron (0.5 l/ha). The application of Ceron (0.5 l/ha) and Architect (0.5 l / ha) growth regulators increased oil content by 3–8 and 4–6 percentage points, respectively. Keywords: sunflower, hybrids, growth regulators, leaf surface area, chlorophyll, yield, seed quality.

Pisum sativum Response to Nitrate as Affected by Rhizobium leguminosarum-Derived Signals

Legumes are suitable for the development of sustainable agroecosystems because of their ability to use atmospheric N2 through symbiotic nitrogen fixation (SNF). However, a basic NO3− input is necessary before SNF takes place to ensure successful seedling establishment. Since Rhizobia not only induce nodulation but also affect root branching by stimulating the development of lateral roots, and NO3− as a signal also modulates root system architecture, we investigated whether Rhizobium-derived signals interfere in nitrate signaling. Here, we bring evidence that (i) Rhizobium-altered NO3−-mediated processes in pea expressions of major players in NO3− transport, sensing, and signaling were affected, and (ii) the characteristic limitation of root foraging and branching in response to NO3− supply was abolished. The number of tertiary roots per secondary root was higher in infected compared to uninfected peas, thus indicating that the Rhizobium effect allows for favorable management of trade-offs between nodules growth for nitrogen capture and root foraging for water and other nutrient uptake in pea. The outcome of this basic research can be used to produce molecular tools for breeding pea genotypes able to develop deep-foraging and branched root systems, and more competitive architectures and molecular levels for soil NO3− absorption during seedling establishment without jeopardizing nodulation.

Genome-Wide Expression Analysis of Root Tips in Contrasting Rice Genotypes Revealed Novel Candidate Genes for Water Stress Adaptation.

Root system architecture (RSA) is an important agronomic trait with vital roles in plant productivity under water stress conditions. A deep and branched root system may help plants to avoid water stress by enabling them to acquire more water and nutrient resources. Nevertheless, our knowledge of the genetics and molecular control mechanisms of RSA is still relatively limited. In this study, we analyzed the transcriptome response of root tips to water stress in two well-known genotypes of rice: IR64, a high-yielding lowland genotype, which represents a drought-susceptible and shallow-rooting genotype; and Azucena, a traditional, upland, drought-tolerant and deep-rooting genotype. We collected samples from three zones (Z) of root tip: two consecutive 5 mm sections (Z1 and Z2) and the following next 10 mm section (Z3), which mainly includes meristematic and maturation regions. Our results showed that Z1 of Azucena was enriched for genes involved in cell cycle and division and root growth and development whereas in IR64 root, responses to oxidative stress were strongly enriched. While the expansion of the lateral root system was used as a strategy by both genotypes when facing water shortage, it was more pronounced in Azucena. Our results also suggested that by enhancing meristematic cell wall thickening for insulation purposes as a means of confronting stress, the sensitive IR64 genotype may have reduced its capacity for root elongation to extract water from deeper layers of the soil. Furthermore, several members of gene families such as NAC, AP2/ERF, AUX/IAA, EXPANSIN, WRKY, and MYB emerged as main players in RSA and drought adaptation. We also found that HSP and HSF gene families participated in oxidative stress inhibition in IR64 root tip. Meta-quantitative trait loci (QTL) analysis revealed that 288 differentially expressed genes were colocalized with RSA QTLs previously reported under drought and normal conditions. This finding warrants further research into their possible roles in drought adaptation. Overall, our analyses presented several major molecular differences between Azucena and IR64, which may partly explain their differential root growth responses to water stress. It appears that Azucena avoided water stress through enhancing growth and root exploration to access water, whereas IR64 might mainly rely on cell insulation to maintain water and antioxidant system to withstand stress. We identified a large number of novel RSA and drought associated candidate genes, which should encourage further exploration of their potential to enhance drought adaptation in rice.

Mechanism of the synergistic impact of Piriformospora indica and Azotobacter chroococcum on Zn and Fe biofortification

• Mechanisms for the enhanced Fe and Zn uptake due to mentioned microbial consortium. • Modified LMWOA profile in root exudates of inoculated plants. • Profusely branched root system of colonized plants. • Enhanced expression of ZIP genes in inoculated plants. This study investigates the mechanisms underlying the enhanced zinc (Zn) and iron (Fe) uptake in a low Zn- and Fe-accumulating Indian wheat genotype HD2967 upon co-inoculation of Piriformospora indica , a phyto-promotional fungal endophyte, and Azotobacter chroococcum , a rhizobacteria, in a hydroponic system. Modifications in root architecture, low molecular-weight organic acid (LMWOA) profile in root exudates, and expression of TaZIP genes in roots and shoots of treated and control plants were analysed. The LMWOA profiles of treated and control plants were investigated using high-performance liquid chromatography, which showed the presence of four LMWOAs: citric, malic, acetic, and succinic acids. A 3.6-fold increase was observed in the total organic acid content of colonised over control plants with citric acid being predominant – representing 90% of the total organic acids. Microbial colonisation caused profuse branching in roots of treated plants with increases in root volume, total surface area, total length, and numbers of tips, forks, and crossings by 1.39-, 1.37-, 1.67-, 1.4-, 1.32-, and 1.81-fold, respectively. Four targeted TaZIP genes ( TaZIP1 , TaZIP3 , TaZIP5 , and TaZIP7 ) were overexpressed in roots and shoots of treated plants as compared to control plants. The results clearly suggest that endophytic colonisation modified the LMWOA profile in root exudates, root morphology, and expression of TaZIP genes in roots and shoots, of colonised hosts would have synergistically facilitated enhanced accumulation of Fe and Zn in colonised plants.

Early sensing of phosphate deprivation triggers the formation of extra root cap cell layers via SOMBRERO through a process antagonized by auxin signaling.

The role of the root cap in the plant response to phosphate deprivation has been scarcely investigated. Here we describe early structural, physiological and molecular changes prior to the determinate growth program of the primary roots under low Pi and unveil a critical function of the transcription factor SOMBRERO in low Pi sensing. Mineral nutrient distribution in the soil is uneven and roots efficiently adapt to improve uptake and assimilation of sparingly available resources. Phosphate (Pi) accumulates in the upper layers and thus short and branched root systems proliferate to better exploit organic and inorganic Pi patches. Here we report an early adaptive response of the Arabidopsis primary root that precedes the entrance of the meristem into the determinate developmental program that is a hallmark of the low Pi sensing mechanism. In wild-type seedlings transferred to low Pi medium, the quiescent center domain in primary root tips increases as an early response, as revealed by WOX5:GFP expression and this correlates with a thicker root tip with extra root cap cell layers. The halted primary root growth in WT seedlings could be reversed upon transfer to medium supplemented with 250 µM Pi. Mutant and gene expression analysis indicates that auxin signaling negatively affects the cellular re-specification at the root tip and enabled identification of the transcription factor SOMBRERO as a critical element that orchestrates both the formation of extra root cap layers and primary root growth under Pi scarcity. Moreover, we provide evidence that low Pi-induced root thickening or the loss-of-function of SOMBRERO is associated with expression of phosphate transporters at the root tip. Our data uncover a developmental window where the root tip senses deprivation of a critical macronutrient to improve adaptation and surveillance.

Spatiotemporal auxin distribution in Arabidopsis tissues is regulated by anabolic and catabolic reactions under long-term ammonium stress

BackgroundThe plant hormone auxin is a major coordinator of plant growth and development in response to diverse environmental signals, including nutritional conditions. Sole ammonium (NH4+) nutrition is one of the unique growth-suppressing conditions for plants. Therefore, the quest to understand NH4+-mediated developmental defects led us to analyze auxin metabolism.ResultsIndole-3-acetic acid (IAA), the most predominant natural auxin, accumulates in the leaves and roots of mature Arabidopsis thaliana plants grown on NH4+, but not in the root tips. We found changes at the expressional level in reactions leading to IAA biosynthesis and deactivation in different tissues. Finally, NH4+ nutrition would facilitate the formation of inactive oxidized IAA as the final product.ConclusionsNH4+-mediated accelerated auxin turnover rates implicate transient and local IAA peaks. A noticeable auxin pattern in tissues correlates with the developmental adaptations of the short and highly branched root system of NH4+-grown plants. Therefore, the spatiotemporal distribution of auxin might be a root-shaping signal specific to adjust to NH4+-stress conditions.

METHODOLOGICAL INSTRUCTIONS FOR THE EFFECTIVE APPLICATION OF GLOBODERA-RESISTANT POTATO VARIETIES IN THE FIGHT AGAINST GOLDEN POTATO NEMATODE IN PERSONAL AUXILIARY FARMS

The decisive link in the system of comprehensive measures to contol the golden potato nematode is the use of globodera-resistant varieties and hybrids of potatoes. Before recommending any globodera-resistant potato variety for private household plots, it is necessary to carry out a comparative assessment of varieties in the globoderosis focus. This purpose is served by demonstration experiments that allow us to identify the positive and negative aspects of varieties and clearly show agricultural specialists and the population the advantages of nematode-resistant varieties. Effectively reduced the number of golden potato nematodes in the soil (by more than 60%) globodera-resistant varieties (Zhukovsky early, Impala, Santa, Scarb, Lady Rosetta, Picasso, Riviera, Arizona, etc.) with a powerful and branched root system when grown on a fertile, light in texture soil with the introduction of mineral and organic fertilizers, sufficient supply of soil moisture during May and June. Their cultivation led to a decrease in the incidence of globoderosis and, accordingly, an increase in potato yield. In order to increase the efficiency of soil disinfection with the help of globodera-resistant varieties and to obtain the optimal potato yield in private household plots, it is necessary to take the following measures: 1. In autumn – autumn plowing to the depth of the arable layer. In spring – cultivation to a depth of 12–14 cm with simultaneous harrowing. 2. It is recommended to cultivate potatoes in an anti-nematode crop rotation or fruit change no earlier than the third or fourth crop. The effectiveness of nematode-resistant varieties increases with the use of organic and full dose of nitrogen fertilizers. 3. To activate the activity of predatory, parasitic fungi and other antagonists of potato nematodes, it is necessary to apply organic fertilizers (manure, peat, compost) to the soil of potato plantings.

Phytoremediation - a green technology adapted to eradication of harmful heavy toxic metals from contaminated soil

Phytoremediation is an alternative technology which makes use of biological processes for detoxifying the harmful pollutants in the environment. Rapid increase of industrialization and various other factors such as agricultural activities, the excessive use of fertilizers, untreated waste, and untreated laboratory effluents lead to degradation of soil as well as environment. The heavy toxic metals plays major role because these are basically crucial for development of plants. These are generally take part in various reduction and oxidation reactions, elementary role in metabolisms of nucleic acids, electrons transferring as a direct participant and being a fundamental part of some essential enzymes. The presence at a minimum threshold amount of these heavy toxic metals in a normal growing medium is vital, but excessive high amount lead to numerous lethal effects. Hence, it becomes our foremost duty towards sustainable development goals to eradicate the toxic harmful metal ions. Certain physical and chemical technologies are used to eradicate such toxins, but due to certain limitations, natural method is preferred which is plants-based technology for eradication of noxious heavy metals from contaminated soil. This technology used from last two decades to solve the problem of eradication of harmful metal ions through plants metabolic pathway in sustainable, environment friendly way. The plants which are used as phytoremediator are generally hyperaccumulators, that can accumulate metal ions in concentration of more than 1000ppm and they must have certain properties such as branched root system, less biomass, easy harvestable. This review article focuses on the sources, harmful effects and various technologies to eradicate heavy metals by using hyperaccumulating plants.

Features of <i>Arabidopsis thaliana</i> photomorphogenesis when using LED-lighting with different spectral composition

In this work we applied the technique of growing A. thaliana Heynh plants on the surface of a hydrated cellulose film under sterile conditions on the gel environment, which was previously developed at the Institute of Biomedical Problems of the Russian Academy of Sciences. Using this technique the plant, including the root system, is fully accessible for observation and its leaves and roots are evenly illuminated. Using this technique, the features of the influence of light with a different ratio of physiologically significant spectral ranges on the morphogenesis of A. thaliana were studied. In the LED- irradiators’ spectral composition which contained all photosynthetically active radiation (PAR) wavelengths we varied the ratio of red/blue (R/B) light from 1 to 5, red/(blue-green) (R/(B + G)) from 0.7 to 4.1 and red/far red (R/FR) from 2.6 to 5.6. Luminescent lighting with R/B, R/(B + G) and R/FR ratios of 2, 1 and 11.9, respectively, was used as a control. The obtained results indicate that the growth of the aerial part and the root system, the synthesis of chlorophyll, the accumulation of dry matter of A. thaliana can be stimulated by increasing the level of red and by decreasing the level of far red light (in the presence of all other parts of PAR), reaching their certain ratio in the spectrum of LED lighting. The most effective spectral composition for the accumulation of dry and wet mass of the aerial part, the synthesizing of chlorophyll as well as for the formation of a branched root system was LED-lighting with R/B, R/(B + G) and R/FR ratios of 4, 2 and 5.6 respectively. In addition, under LED illumination of all variants, plants formed peduncles on average 5-6 days earlier and their number was greater than under luminescent one.

Устойчивый к засухе сорт сои Волгоградка 1

The constant intensification of global soybean production is closely related to the breeding and seed production of this crop. Therefore, the research focused on the development of new varieties is quite relevant. The long-term screening at various agricultural backgrounds in dry and relatively favorable years helped identify a high drought resistance of soybean line 214, named Volgogradka 1, which is included in the State Register of varieties approved for use in the Lower Volga region (Russia) and Ural region (Kazakhstan). The variety is of medium-early 33 ripening, tall with a semi-determinant type of growth and a semi-compressed bush shape. It is characterized by high resistance to the main soybean diseases, such as Septoria blight, bacteriosis, mosaic compared to the standard varieties. It develops a high yield of biomass - from 3.29 to 10 t/ha in dry matter, which is higher than the standards (3.58-6.39 t/ha), so it is ideal for use on monofodder, it is a good predecessor that enriches the soil with nitrogen. Due to the high linear growth and, consequently, to the root system deeply developed in the soil, the semi-determinant type of development, the agrocenosis of the variety Volgogradka 1 can effectively use a small amount of precipitation during the growth season and at a low hydrothermal coefficient of the territory. The variety Volgogradka 1 is able to develop from 2.51 to 3.85 t/ha of grain in crops with irrigation due to its increased branching, tallness, resistance to lodging of the stem and a highly branched root system, which significantly exceeds the standard varieties in this indicator. The expansion of Volgogradka 1 sowings under irrigation conditions will increase the yield of soybean and to accelerate its import substitution.

The promoted lateral root 1 (plr1) mutation is involved in reduced basal shoot starch accumulation and increased root sugars for enhanced lateral root growth in rice

Lateral roots (LRs) are indispensable for plant growth, adaptability and productivity. We previously reported a rice mutant, exhibiting a high density of thick and long LRs (L-type LRs) with long parental roots and herein referred to as promoted lateral root1 (plr1). In this study, we describe that the mutant exhibited decreased basal shoot starch accumulation, suggesting that carbohydrates might regulate the mutant root phenotype. Further analysis revealed that plr1 mutation gene regulated reduced starch accumulation resulting in increased root sugars for the regulation of promoted LR development. This was supported by the exogenous glucose application that promoted L-type LRs. Moreover, nitrogen (N) application was found to reduce basal shoot starch accumulation in both plr1 mutant and wild-type seedlings, which was due to the repressed expression of starch biosynthesis genes. However, unlike the wild-type that responded to N treatment only at seedling stage, the plr1 mutant regulated LR development under low to increasing N levels, both at seedling and higher growth stages. These results suggest that plr1 mutation gene is involved in reduced basal shoot starch accumulation and increased root sugar level for the promotion of L-type LR development, and thus would be very useful in improving rice root architecture.

Auxin-mediated root branching is determined by the form of available nitrogen.

To improve water and nutrient acquisition from the soil, plants can modulate their root system architecture. Despite the importance of changes in root architecture to exploit local nutrient patches occurring in heterogenous soils or after placed fertilization, mechanisms integrating external nutrient signals into the root developmental programme remain poorly understood. Here, we show that local ammonium supply stimulates the accumulation of shoot-derived auxin in the root vasculature and promotes lateral root emergence to build a highly branched root system. Activities of pH and auxin reporters indicate that ammonium uptake mediated by ammonium transporters acidifies the root apoplast, which increases pH-dependent import of protonated auxin into cortical and epidermal cells overlaying lateral root primordia, and subsequently promotes their emergence from the parental root. Thereby, ammonium-induced and H+-ATPase-mediated acidification of the apoplast allows auxin to bypass the auxin importers AUX1 and LAX3. In nitrogen-deficient plants, auxin also accumulates in the root vasculature but a more alkaline apoplast leads to retention of auxin in these tissues and prevents lateral root formation. Our study highlights the impact of externally available nitrogen forms on pH-dependent radial auxin mobility and its regulatory function in organ development.