Aboveground Plant Parts Research Articles

PHYTOCHEMICAL STUDY OF THE ENDEMIC SPECIES OF DAGESTAN FLORA – DIANTHUS AWARICUS KHAR. (CARYOPHYLLACEAE) DURING INTRODUCTION

Introduction. The study and rational use of wild plants of the local flora is one of the priority areas in the development of pharmaceutical chemistry aimed at finding new drugs. The work highlights some phytochemical aspects applicable to the carnation avar (Dianthus awaricus Khar.), an endemic species for the Republic of Dagestan, introduced under conditions Tsudakhar experimental base of the Mountain Botanical Garden of the DFRC RAS (1100 m above sea level), for a comparative study of phenolic compounds in plants and expansion of the cultigenic range of the wild and white-flowered carnation species. The purpose of the study is a preliminary study and assessment of the total content of flavonoids and anthocyanins in various organs of the endem-ic species of Dagestan flora – Dianthus awaricus Khar., as well as a comparative analysis of the weight of hundreds of seeds and the content of fatty oil in seeds under the conditions of introduction. Materials and methods. The object of the study is a white-flowered endemic species – Dianthus awaricus Khar. The total content of flavonoids and anthocyanins and fatty oil was determined using standard methods. Results. The conducted studies using the spectrophotometric method revealed that the highest content of flavonoids is observed in the flowers, leaves and seeds of D. awaricus. The maximum content of flavonoids is observed in the flowers of the sample "Tsudahar" (1.078%), in the leaves (0.980%) and flowers (0.925%) – "Gunib". In terms of anthocyanin content, the leaves, stems and above-ground parts of plants without seeds differ most favorably (0.051–0.077%). Conclusions. For the first time, phytochemical studies were conducted on the content of phenolic compounds in plants of various natural samples and fatty oil (9.9–10.5%) in D. awaricus seeds under the conditions of the Tsudakhar experimental base. Data on the chemical composition of phenolic compounds in the above-ground part of D. awaricus significantly increases the possibilities for assessing the prospects of this type of raw material.

Intraspecific and intra-individual chemodiversity and phenotypic integration of terpenes across plant parts and development stages in an aromatic plant.

Some plant species produce an extraordinary diversity of specialized metabolites. The diverse class of terpenes is characteristic for many aromatic plants, and terpenes can occur as both emitted volatiles and stored compounds. Little is known about how intraspecific chemodiversity and phenotypic integration of both emitted volatile and stored terpenes differ intra-individually across plant development and between different plant parts, and studies considering both spatial and temporal scales are scarce. To comprehensively investigate this diversity, we used the aromatic plant Tanacetum vulgare that differs in foliar terpene composition, forming chemotypes. We collected emitted volatile terpenes of both young and old leaves during the rosette, elongated stem, and flowering stage as well as emitted volatiles of flower heads at the flowering stage. Moreover, at the flowering stage, stored terpenes were extracted from different plant parts, including roots. Terpene profiles were measured with (TD)-GC-MS. The composition of emitted volatile terpenes depended on the specific combination of chemotype, plant part, and time point; the chemodiversity of emitted volatiles was mainly affected by the development stage, indicating that at specific development stages individuals require a higher chemodiversity, potentially to mediate different interactions. For stored terpenes, intra-individual differences, mostly between aboveground and belowground plant parts, were found only for specific components of chemodiversity, such as richness and evenness, but not for functional Hill diversity. Phenotypic integration differed mainly across development stage and plant part for emitted volatile terpenes, and across chemotype and plant part for stored terpenes. Our results suggest that intraspecific chemodiversity of terpenes and their integration is a highly plastic trait that may be shaped in dependence of interactions with the environment, and the value that each plant part contributes to the fitness of an individual. Such variation on different scales, both spatially and temporally, should be considered in chemical ecological studies.

Evaluation of volatile oil components of Salvia multicaulis (Vahl) plant growing in Malatya-Akçadağ region

This study aimed to determine the chemical content of the Salvia multicaulis Vahl plant collected in two different locations (38°27’07.9”N 38°01’56.6”E; 38°29’53.0”N 37°55’55.0”E) in Akçadağ district of Malatya province. The essential oils of the above-ground parts of plants were prepared with Clevenger apparatus. The plant was collected in May, June, and July in two different locations. According to analysis of GC-MS the major components were identified as eucalyptol (13.88, 18.39%; 14.89, 21.33%; 19.57, 23.29%), α-pinene (11.60, 10.02%; 13.72, 11.00%; 11.64, 11.69%), and camphor (10.87, 7.43%; 16.02, 6.18%; 16.41, 4.70%)

Can the agrochemical Oryzemate treatment control the uptake of pyrene by Cucurbita pepo through the regulation of major latex-like proteins?

Members of the Cucurbitaceae family accumulate several hydrophobic organic pollutants in their above-ground parts at high concentrations. Major latex-like proteins (MLPs) identified in Cucurbita pepo bind to hydrophobic organic pollutants, such as pyrene and dieldrin, in roots, forming complexes that are transported via xylem vessels to the above-ground plant parts. However, soil remediation of hydrophobic organic pollutants utilizing MLPs has not been established. In this study, the uptake of the hydrophobic organic pollutant pyrene by C. pepo was promoted through the upregulation of the expression of MLP genes following agrochemical treatment. Probenazole, an active ingredient in the agrochemical Oryzemate, was previously found to upregulate the promoter activity of MLP genes in the roots of transgenic tobacco plants. Here, Oryzemate treatment increased the levels of MLPs in the roots and xylem sap of C. pepo. Oryzemate treatment slightly increased and significantly decreased the pyrene concentration in the xylem sap of C. pepo cultivated in high- and low-contamination soils, respectively. Probenazole competitively inhibited the binding of MLPs to pyrene in vitro, thereby likely suppressing its uptake by C. pepo in low-contamination soil. This study demonstrated that Oryzemate possesses dual effects: effective phytoremediation and safe crop production, depending on the soil contamination level.

Pseudomonas rhodesiae HAI-0804 suppresses Pythium damping off and root rot in cucumber by its efficient root colonization promoted by amendment with glutamate.

Plant diseases caused by soil-borne fungi and oomycetes significantly reduce yield and quality of many crops in the agricultural systems and are difficult to control. We herein examine Pseudomonas rhodesiae HAI-0804, a bacterial biological control agent that was originally developed for control of bacterial diseases on the surface of vegetables, and assessed its efficacy at controlling soil-borne diseases caused by oomycetes. Strain HAI-0804 did not exhibit detectable antibiotic activity toward Pythium ultimum, a causal agent of damping-off and root rot; however, it effectively protected against Pythium damping-off and root rot in cucumber. Exogenous glutamate enhanced the efficacy of biocontrol, the production of siderophore pyoverdine, root colonization in cucumber plants, and the ratio of biofilm formation to planktonic cells. The epiphytic fitness of strain HAI-0804 appears to contribute to plant protection efficacy against a broad spectrum of pathogens for both above-ground plant parts and the rhizosphere.

Black shank-mediated alteration of the community assembly of rhizosphere soil bacteria in tobacco.

There is a close and complex interaction between the elements in the aboveground-underground ecosystem during the growth and development of plants. Specifically, when the aboveground part of plants is infected by pathogens, it induces the plant rhizosphere to synthesize specific root exudates. Consequently, a group of beneficial rhizosphere soil bacteria is recruited to help plants resist diseases. However, the changes in the rhizosphere soil bacterial community of plants under infection by oomycete pathogens remain unknown. Three experimental treatments were set up in this experiment: soils inoculated with P. nicotianae, no-inoculation with P. nicotianae, and a control. The control treatment was composed of soils without transplanted tobacco plants, with the pathogen inoculated twice at an interval of eight days to ensure a successful P. nicotianae infection. P. nicotianae inoculation treatments were designed using the hyphal block inoculation method. In the non-inoculation treatment, tobacco plants were grown normally without pathogen inoculation. The tobacco plants were grown in a greenhouse. This study demonstrates that tobacco plants recruit microorganisms at the rhizosphere level as a defense mechanism against disease after infection by the oomycete pathogen Phytophthora nicotianae. Specific rhizosphere soil bacteria were screened in vitro to promote tobacco growth in a biofilm-forming manner, which induced the systemic resistance of the plants to P. nicotianae. The recruitment of rhizosphere soil bacteria to the inter-root zone of tobacco plants after infection by P. nicotianae can help subsequently cultivated tobacco plants in the same soil resist pathogen infestation. In conclusion, the present study confirms that infestation caused by oomycete pathogens alters the composition of the plant rhizosphere soil bacterial community and recruits a specific group of beneficial microorganisms that induce disease resistance and promote plant growth, thereby maximizing the protection of progeny grown in the same soil against the disease.

Migration of Plutonium, Micro- and Macroelements in the “Soil–Plant” System at Different Soil Moisture

In the vegetation experiment, the plutonium, micro- and macroelements migration in the “soil–agricultural plant” system depending on soil moisture in the range from 15 to 40٪ of absolute soil moisture were studied. The content of 239Pu was analyzed by α-spectrometry with preliminary radiochemical isolation. The elemental composition was analyzed by the ICP-MS and ICP-AES methods. Beans (Fabaceae) variety “Amber” were used as a test culture. The plutonium transfer factor obtained in the vegetation experiments are in the range of of 5.3×10–4–1.5×10–2, with an average value of 5.4×10–3 for the aboveground part of bean and range of 4.5×10–2–2.7×10–1, with an average of 1.6×10–1 for bean roots. It was determined that the distribution of plutonium, micro and macro elements in the vegetative organs of plants is not equally, the transfer factor of plutonium for the aboveground part of plants is lower than for the root part. It has been established that the accumulation of plutonium, micro- and macroelements, depending on soil moisture, is different for the organs of beans. The dependence of plutonium accumulation by plants on soil moisture is significantly higher than for other considered elements. A decrease in the coefficient of accumulation of plutonium in the aerial part of the beans is recorded with an increase in soil moisture up to two orders of magnitude. There is a trend towards a slight decrease in the accumulation coefficients of Fe, Mg, Mn, Cr, Mo, Ni, Co, Cu. For the root system of beans, a clear dependence of the accumulation of the considered elements on soil moisture is not observed.

PhytOC sequestration characteristics and phytolith carbon sink capacity of the karst grasslands in southwest China

Grassland is an important component of terrestrial ecosystems and plays a crucial role in the global carbon cycle. PhytOC (phytolith-occluded organic carbon) is an extremely important long-term and stable carbon pool in terrestrial ecosystems. Southwest China karst soil exhibits obvious characteristics of alkalinity, high silicon content, and rich calcium, which can significantly influence the characteristics and mechanisms of PhytOC sequestration in vegetation. To elucidate the sequestration characteristics and mechanisms of PhytOC in the karst grasslands, three typical karst grasslands of tropical shrub tussock (TST), warm-temperate shrub tussock (WST), and mountain meadow (MM) from Guizhou province of southwest China were studied. The following results and conclusions were obtained that: 1) the range of PhytOC content of aboveground plant parts, underground roots, and soil in the karst grasslands was 4.03–16.54 g·kg−1, 10.67–33.92 g·kg−1, and 0.63–1.89 g·kg−1, respectively. The underground roots are an important site for phytolith carbon sequestration in grassland ecosystems, and the PhytOC content of underground roots may be higher than that of the aboveground parts. 2) The PhytOC sequestration rate of vegetation was 7.34–15.93 kg·ha−1·yr−1, and the annual sequestration amount of PhytOC of the whole grasslands in southwest China could reach 0.48 × 103–1.48 × 103 t CO2. Compared to grasslands in non-karst regions of China, karst grasslands in southwest China have a higher sequestration rate of PhytOC in vegetation and a greater capacity for phytolith carbon sequestration. 3) Soil available silicon, pH, and stoichiometric characteristics of C, N and P nutrients significantly affected the phytolith carbon sequestration of vegetation and the soil accumulation of PhytOC in the karst grasslands. The research results are of great significance for estimating the phytolith carbon sequestration capacity of grassland ecosystems and for grassland construction and management based on enhancing carbon sequestration.

The Application of a Foliar Spray Containing Methylobacterium symbioticum Had a Limited Effect on Crop Yield and Nitrogen Recovery in Field and Pot-Grown Maize.

In this study, the effectiveness of an inoculant containing a nitrogen (N)-fixing microorganism (Methylobacterium symbioticum) was evaluated on maize (Zea mays L.) grown both in the field (silage maize) and in pots over two years (2021 and 2022). The field trial included the following two treatments: with (Yes) and without (No) the inoculant. The pot experiment was designed as a factorial arrangement with two factors: the application of the inoculant (Yes and No) and N applied to the soil (0, 0.4, 0.8, and 1.6 g pot-1). In the field, total dry matter yield (DMY) did not differ significantly between treatments, although the average DMY was higher in the inoculant treatment. In pots, the total DMY varied significantly across all N rates but was only significantly affected by the inoculant application in 2022. N fixation estimates in the field were 58.8 and 14.5 kg ha-1 for 2021 and 2022, respectively, representing 23.7% and 9.1% of the N recovered in the aboveground plant parts. In pots, the estimated fixed N values were -49.2 and 199.2 mg pot-1 in 2021 and 2022, respectively, which corresponded to -5.2% and 18.5% of the N found in the aboveground plant parts. Considering the average values obtained across the four cultivation conditions, there was a positive outcome for the treated plants. However, these values cannot be considered significant when compared to nitrogen removal in maize crops. A commercial product should provide an unequivocal and quantitatively relevant contribution to plant nutrition, which did not appear to be the case. Thus, for this inoculant to provide reliable guarantees of positive outcomes for farmers and become a useful tool in promoting more sustainable agriculture, further studies appear necessary. These studies should aim to determine in which crops and under what cultivation conditions the application of the inoculant is truly effective in enhancing N fixation and improving crop productivity.

Stoichiometric and Accumulation Characteristics of Nitrogen and Phosphorus in Artificial and Natural Herbaceous Plants along Lakeshore Buffer Zone

Lakeshore buffer zones serve as transitional areas between terrestrial and aquatic ecosystems, playing a crucial role in intercepting non-point source pollutants, purifying river and lake water, and maintaining ecological system dynamics. This study focuses on the vegetation of the lakeshore buffer zone in Songhua Lake, the largest artificial lake in Northeast China. The nitrogen (N) and phosphorus (P) pollutant contents and accumulation characteristics of herbaceous plants were investigated and analyzed in different regions and with different species. The study results indicate that there were no significant differences in N and P content, N: P ratio, and average accumulation among vegetation in the near-water, middle, and far lakeshores of the buffer area. The herbaceous plants with the highest N and P content and N: P ratios were Artemisia sieversiana, Sium suave, and Artemisia sieversiana, respectively. Purus frumentum planted in the middle lakeshore accumulated the highest amounts of N and P, reaching 87.97 g plant−1 and 3.86 g plant−1, respectively. The aboveground parts of plants showed significantly higher accumulation of N and P compared to the underground parts. The average enrichment coefficient for aboveground parts and underground parts for N were 4.83 and 4.35, respectively, all exceeding 1. However, their capability to enrich P was relatively weak, with only the aboveground parts of F − 3 showing some enrichment ability. Among herbaceous plants, Artemisia sieversiana and Sium suave exhibited the strongest capability for transporting N and P from underground to aboveground. Overall, harvesting aboveground biomass for the ecological removal of N and P in the study area appears feasible. Biomass is a critical factor influencing the nutrient interception capacity of vegetation, with Purus frumentum identified as an optimal restoration plant for sustainable management practices, and Artemisia sieversiana and Sium suave have the potential for rapid remediation.

Use of Cannabis sativa L. for Improving Cadmium-Contaminated Mediterranean Soils—Effect of Mycorrhizal Colonization on Phytoremediation Capacity

Although the phytoremediation strategy has been studied worldwide, little research data are available regarding the influence of mycorrhizae on the phytoremediation capacity of various plants grown in Cd-contaminated soils in Mediterranean environments. Therefore, a pot experiment was carried out to study the possible effectiveness of hemp plant (Cannabis sativa L.) in the remediation of moderately and heavily Cd-contaminated soils and additionally to quantify the effect of Cd on Arbuscular Mycorrhizal Fungi (AMFs). For this purpose, an alkaline clay soil collected from the Farm of Institute of Plant Breeding and Genetic Resources (North Greece) was contaminated with two levels of Cd (3 and 30 mg Cd kg−1, corresponding to Levels A and B, respectively—first factor) at two incubation times (10 and 30 days—second factor) and six treatments (Control_30d, Control_10d, CdA_30d, CdB_30d, CdA_10d, CdB_10d) were created. Soil Cd concentrations, both pseudo-total and available to plants, were determined after extraction with Aqua Regia mixture and DTPA solution, respectively, before and after the cultivation of hemp plants and after the harvesting. Cd concentrations in the aboveground and underground plant parts were also estimated after digestion with Aqua Regia, while root colonization by AMFs was determined with a microscope. The highest plant’s Cd concentration, more than 50%, was observed in its underground part, at all Cd-contaminated treatments, indicating a strong capacity for cadmium to gather up in the roots. Among different Cd levels and incubation days, significant differences were recorded in the rates of root colonization by AMFs. Among different Cd levels and incubation days, 3 mg Cd Kg−1 soil promoted AMF root colonization, particularly at 10-day incubation, while 30 mg Cd Kg−1 soil diminished it. Colonization was lower with longer incubation times at both levels of Cd. Hemp appears to be a viable option for phytostabilization in Cd-contaminated soils, enabling further utilization of AMFs to assist the phytoremediation process.

Microplastic and Nanoplastic in Crops: Possible Adverse Effects to Crop Production and Contaminant Transfer in the Food Chain.

With the increasing amounts of microplastic (MP) deposited in soil from various agricultural activities, crop plants can become an important source of MP in food products. The last three years of studies gave enough evidence showing that plastic in the form of nanoparticles (<100 nm) can be taken up by the root system and transferred to aboveground plant parts. Furthermore, the presence of microplastic in soil affects plant growth disturbing metabolic processes in plants, thus reducing yields and crop quality. Some of the adverse effects of microplastic on plants have been already described in the meta-analysis; however, this review provides a comprehensive overview of the latest findings about possible adverse effects and risks related to wide microplastic occurrence in soil on crop production safety, including topics related to changes of pesticides behavior and plant pathogen spreading under the presence MP and possibly threaten to human health.

A resilient mutualistic interaction between cucumber mosaic virus and its natural host to adapt to an excess zinc environment and drought stress.

A perennial pseudometallophyte Arabidopsis halleri is frequently infected with cucumber mosaic virus (CMV) in its natural habitat. The purpose of this study was to characterize the effect of CMV infection on the environmental adaptation of its natural host A. halleri. The CMV(Ho) strain isolated from A. halleri was inoculated into clonal virus-free A. halleri plants, and a unique plant-virus system consisting of CMV(Ho) and its natural wild plant host was established. In a control environment with ambient zinc supplementation, CMV(Ho) infection retarded growth in the above-ground part of host plants but conferred strong drought tolerance. On the other hand, in an excess zinc environment, simulating a natural edaphic environment of A halleri, host plants hyperaccumulated zinc and CMV(Ho) infection did not cause any symptoms to host plants while conferring mild drought tolerance. We also demonstrated in Nicotiana benthamiana as another host that similar effects were induced by the combination of excess zinc and CMV(Ho) infection. Transcriptomic analysis indicated that the host plant recognized CMV(Ho) as a mutualistic symbiont rather than a parasitic pathogen. These results suggest a resilient mutualistic interaction between CMV(Ho) and its natural host A. halleri in its natural habitat.

Endophytic Colletotrichum fructicola KL19 and Its Derived SeNPs Mitigate Cd-Stress-Associated Damages in Spinacia oleracea L.

The application of nanotechnology in agriculture has received much attention in order to improve crop yield, quality and food safety. In the present study, a Cd-tolerant endophytic fungus Colletotrichum fructicola KL19 was first ever reported to produce SeNPs, and the production conditions were optimized using the Box-Behnken design in the Response Surface Methodology (RSM-BBD), achieving a peak yield of 1.06 mM under optimal conditions of 2.62 g/20 mL biomass, 4.56 mM Na2SeO3, and pH 6.25. Following this, the properties of the biogenic SeNPs were elucidated by using TEM, DLS, and FTIR, in which the 144.8 nm spherical-shaped SeNPs were stabilized by different functional groups with a negative zeta potential of -18.3 mV. Furthermore, strain KL19 and SeNPs (0, 5, 10, 20 and 50 mg/L) were inoculated in the root zone of small-leaf spinach (Spinacia oleracea L.) seedlings grown in the soil with 33.74 mg/kg Cd under controlled conditions for seven weeks. Impressively, compared with Cd stress alone, the strain KL19 and 5 mg/L SeNPs treatments significantly (p < 0.05) exhibited a reduction in Cd contents (0.62 and 0.50 folds) within the aboveground parts of spinach plants and promoted plants' growth by improving the leaf count (0.92 and 1.36 folds), fresh weight (2.94 and 3.46 folds), root dry weight (4.00 and 5.60 folds) and root length (0.14 and 0.51 folds), boosting total chlorophyll synthesis (0.38 and 0.45 folds), enhancing antioxidant enzymes (SOD, POD) activities, and reducing the contents of reactive oxygen species (MDA, H2O2) in small-leaf spinach under Cd stress. Overall, this study revealed that utilizing endophytic fungus C. fructicola or its derived SeNPs could mitigate reactive oxygen species generation by enhancing antioxidant enzyme activity as well as diminish the absorption and accumulation of Cd in small-leaf spinach, promoting plant growth under Cd stress.

High-throughput digital imaging and detection of morpho-physiological traits in tomato plants under drought

Abstract Advances in informatics, robotics, and imaging techniques make it possible to use state-of-the-art digital reconstruction technologies for high-throughput plant phenotyping (HTPP) affected by stress factors, as well as for the ontology of their structural and functional traits. Digital imaging of structural and functional features of the aboveground part of plants is non-destructive and plants can be monitored throughout their entire life cycle. In the experiment with tomato plants (Solanum lycopersicum L.; cv. Gruzanski zlatni) grown in controlled environmental conditions and affected by gradual soil dehydration, we evaluated phenotypic traits and phenotypic plasticity by the PlantScreenTM platform using digital imaging of plant optical signals. In this study, 25 different morpho-physiological traits of the plant were evaluated during the precise control and monitoring of the water content in the soil. Different levels of plant water supply induced statistically significant differences in the formation of individual phenotypic traits. Several plant traits have been identified that are characterized by low variability in both well-hydrated and water-stressed conditions, as well as traits with high phenotypic plasticity. Geometric traits (especially Isotop, Round-2top, and Compside) showed a relatively low level of drought-induced phenotypic plasticity. However, functional and chemometric characteristics (ΔF/F′m, Rfd, Water-1, and ARI-1) showed the potential to exhibit rapid plasticity in water-stressed conditions. Our results confirmed that a high-throughput phenotyping methodology coupled with advanced statistical analysis tools can be successfully applied to characterize crop stress responses and identify traits associated with crop stress tolerance.

Optimization of the Method for Isolating Bacterial DNA from the Aboveground Part of Lettuce.

Developing an effective method for isolating bacterial genetic material from plants is a relatively challenging task and often does not yield adequately prepared material for further analyses. Previous studies often overlook connections, primarily focusing on laboratory investigations. With advancements in high-throughput sequencing techniques, we can now revisit and delve deeper into these interactions. Our study focuses on the initial phase of these investigations: genetic material isolation. Extracting bacterial DNA from aboveground plant parts, known as the phyllosphere, poses a significant challenge due to plant-derived contaminants. Existing isolation protocols frequently yield inconsistent results, necessitating continuous refinement and optimization. In our study, we developed an effective isolation protocol employing mechanical-chemical lysis, sonication, and membrane filtration. This approach yielded high-quality DNA at a concentration of 38.08 ng/µL, suitable for advanced sequencing applications. Our results underscore the effectiveness and necessity of these methods for conducting comprehensive microbiological analyses. Furthermore, our research not only lays the groundwork for further studies on lettuce microbiota, but also highlights the potential for utilizing our developed protocol in investigating other plants and their microbiomes.

The accumulation of aluminum in the aboveground parts of green manure plants belonging to the Brassicaceae family

The accumulation of aluminum in the aboveground parts of green manure plants belonging to the Brassicaceae family

ОПРЕДЕЛЕНИЕ ФИТОТОКСИЧНОСТИ СУБСТРАТОВ НА ОСНОВЕ ОТХОДОВ АКТИВНОГО ИЛА В ВЕГЕТАЦИОННЫХ ОПЫТАХ

The aim of the study is to determine the phytotoxicity of components and substrates using waste from the treatment facilities of the Arkhangelsk Pulp and Paper Mill. The substrates were made on the basis of high-moor peat with a decomposition degree of 15 %, with the addition of Biohumus Arkhangelsky, which is composted residual activated sludge from treatment facilities (RAS). To test extracts from materials used to prepare experimental substrates, oats (Avena sativa L.) and watercress (Lepidium sativum L.) were used. Comparison was carried out with distilled water and Knop's mixture. To select the optimal ratio of residual activated sludge and peat for plant growth, a model experiment was conducted with growing oats. The substrates prepared by the volume of fractions with a gradation of activated sludge of 10 % were studied. It was found that composted activated sludge does not have phytotoxicity in relation to the test objects. The extract based on dewatered activated sludge of the treatment facilities of the Arkhangelsk Pulp and Paper Mill does not have a depressing effect on the germination of test objects – oat and watercress seeds, and according to the indicators of the length of the root and coleoptile of oats, it has a stimulating effect comparable to or exceeding the effect of the Knop mixture. Phytostimulating effect of peat extract was not detected. The addition of OAI to high-moor peat during the preparation of substrates has a positive effect on growth indicators. An increase in the length of the stem and root, the mass of the underground and aboveground parts of plants is noted. The optimal addition to the substrate for growing oats is composted activated sludge in the amount of 10–20 %. With large proportions of composted activated sludge waste (more than 40 %), oat growth decreases, but the mass of stems and roots increases.

Isolation and identification of phyllosphere bacteria from three different crops

The phyllosphere represents the habitat provided by the aboveground parts of plants. There have been few studies on the phyllosphere of plants. A large number of microbes are associated with the phyllosphere, where bacteria are the most dominant. The main objective of the present study was to isolate phyllosphere bacteria from three different crops cultivated in the Jaffna district. Phyllosphere bacteria were isolated by washing the host leaf and plating on nutrient agar media. Two different phyllosphere bacteria, namely, Pseudomonas putida and Staphylococcus equorum and two different species of the genus Bacillus (B. cereus and B. pumilus)were isolated from Zea mays. Staphylococcus epidermis and two different species of Bacillus (B. cereus and B. subtilis) were isolated from Solanum lycopersicum. Two different phyllosphere bacteria, namely, Lactobacillus brevis and Micrococcus luteus, and three different species of Bacillus (B. subtilis, B. mycoides and B. licheniformis) were isolated from Brassica oleracea var. capitata. The isolates were identified based on colony morphological characteristics and biochemical tests.

Active ingredient identification and purification of organosilicon spray adjuvant and its uptake and translocation in rice (Oryza sativa L.).

The assessment of residue, absorption, conduction, and degradation of agricultural organosilicon surfactants in the environment is hindered by the lack of information on active ingredients and corresponding quantitative standards for organosilicon spray adjuvants. The spray adjuvant 'Jiexiaoli,' a primary organosilicon spray agent in China, was identified as hydroxy (polyethylene) propyl-heptamethyl trisiloxane (TSS-H) with 3-15 ethoxy (EO) groups. Purification of TSS-H was achieved through semi-preparative separation using high-performance liquid chromatography (HPLC), resulting in TSS-H purity exceeding 96%. An accurate residual detection method for nine oligomers (4-12 EO) of TSS-H in rice roots, stems, leaves, and culture solution samples was developed using HPLC tandem high-resolution mass spectrometry (HPLC-HRMS). Recoveries for nine oligomers of TSS-H in the four matrices ranged from 80.22% to 104.01%. Foliar application experiments demonstrated that TSS-H did not transfer from the upper to the lower parts of the rice plant. The half-lives of each oligomer (4-12 EO) in leaves were less than 3.21 days. Root application experiments revealed a root concentration factor (RCF) ranging from 0.20 to 0.56, a biological enrichment factor (BCF) ranging from 0.36 to 0.68, a transpiration factor (TSCF) ranging from 0.069 to 0.086, and a transport factor (TF) ranging from 0.08 to 0.43. These results indicated that TSS-H could be absorbed by rice roots and conducted to the above-ground parts of rice plants. This study fills the data gap in the environmental risk and food safety assessment of agricultural silicone spray adjuvants. © 2024 Society of Chemical Industry.