Stages Of Vegetative Development Research Articles

Lipazy roślinne – struktura molekularna, rola w ontogenezie oraz potencjał biotechnologiczny

Lipases are enzymes commonly found in microorganisms, fungi, plants and animals. Their main function in cell metabolism is the hydrolysis (lipolysis) of ester bonds between fatty acids and glycerol in mono-, di- and triacylglycerols. In plants, lipases play an important role in ontogeny, participating in both vegetative development and generative stages. These enzymes may also be a component of plant responses to biotic and abiotic stresses. Based on the similarity of the amino acid sequence and vacuolar localization of some plant lipases to yeast Atg15, we present a hypothesis about the participation of lipases in autophagy (precisely, in the degradation of the autophagic body) in plants. Despite the narrow substrate specificity and the type of reactions catalysed in cells, lipases find numerous biotechnological applications. The physicochemical features of lipases, which determine, for example, wide substrate specificity in vitro or high stability in a wide range of pH and temperature, make these enzymes the subject of applied research, and plant lipases show an increasing potential in this area of science and industry.

Development of a temperate rainforest zonation on the Pacific slopes of the North Patagonian Andes since ∼18 ka

Few studies along the western slopes of the Andes in Northwestern Patagonia (NWP: 40°-44°S) allow examining vegetation development through environmental gradients in latitude and elevation along a time continuum since the Last Glacial Termination (T1, ∼18-11 ka). This complete biostratigraphic context is necessary for assessing the sequence, timing, rates, and direction of compositional/structural changes of the former vegetation, and for deciphering their environmental drivers. Here we report palynological results from two NWP sites spaced ∼22 km apart on the western Andean slopes, Caleta Puelche roadside section located near sea level and Lago Reflejos at mid elevations (∼800 m a.s.l.) and assess their continuous records since local ice-free conditions against other NWP sites. We find that cold-tolerant early successional trees dominated the initial stages of vegetation development in the Seno Reloncaví lowlands (∼18-17 ka), followed by thermophilous shade-tolerant North Patagonian rainforest (NPRF) trees, which achieved their maxima between ∼17 and 15 ka at low-elevations. A spread of cold- and shade-tolerant hygrophilous NPRF conifers ensued (∼14.8-13 ka) reaching similar magnitude at low- and mid-elevations, interrupted by increases in trees favored by canopy fragmentation linked to fire and explosive volcanism (∼13-11 ka). Thermophilous, shade-intolerant, summer-drought tolerant Valdivian rainforest (VRF) trees increased and achieved maxima between ∼10 and 8 ka, most notably in the lowlands, coeval with peak abundance of the NPRF conifers Fitzroya/Pilgerodendron and Podocarpus nubigena in mid-elevation Lago Reflejos, contemporaneous with their virtual disappearance near sea level. Widespread increases in cold-tolerant hygrophilous NPRF trees occurred after ∼8 ka, followed by mixing of NPRF and VRF elements in the lowlands after ∼6.3 ka with centennial-scale alternations. Inter-site and regional coherences of our findings suggest that variations in Southern Westerly Wind influence, along with disturbance regimes of natural and human origin, have driven the composition, structure, dynamics, and zonation of temperate rainforests in NWP since T1. We observe that Lago Reflejos features the highest abundance of Fitzroya cupressoides at regional scale since ∼12 ka, attesting to the importance of mid-elevation Andean environments for the persistence of these highly valued trees in the context of postglacial climate evolution, shifts in fire regimes, volcanic, and human disturbance in NWP.

Plant tolerance to drought stress: Complexity and mechanism across physiological, molecular and biochemical scales

Drought stress limits crop yield globally and is growing as a result of climate change. Water deficit of soil frequently reduces crop growth and yield regardless of developmental stages and nature of genotypes. There are a variety of mechanisms involved in plants in response to drought stress and they trigger the plant drought tolerance strategies. Plants subjected to drought undergo a sequence of physiological, biochemical, and molecular mechanisms to combat the effects of drought, just like plants exposed to other environmental stressors. Using various methods, researchers are currently attempting to understand the intricate operation of the drought stress response in plants. During particular crucial stages such as seed germination, and formation of seedlings, flowering, and grains, plants are particularly vulnerable to drought stress. Through the activation of tolerance mechanisms, plants successfully mitigate the impacts of drought stress during vegetative development stages. However, drought stress during the generative phase might result in yield losses that are irreversible. The present review highlights the tolerance mechanisms in plants and the functioning of physiological, molecular, and biochemical processes involved in plants' resistance to water deficit as well as how various crops react to drying conditions at various developmental points.

Application of Biostimulant in Seeds and Soil on Three Chickpea Varieties: Impacts on Germination, Vegetative Development, and Bacterial Facilitation of Nitrogen and Phosphorus.

Chickpeas (Cicer arietinum L.) are a valuable legume crop due to their nutritional value. To maintain chickpea productivity and avoid the adverse effects of climate change on soil and plant processes, it is crucial to address demand. Achieving this necessitates implementing sustainable agricultural practices incorporating the use of biostimulants, adaptable crops for arid conditions, as well as pest and disease-resistant crops that are sustainable over time. Three varieties of chickpeas were analysed to determine the effect of two different biostimulant application methods on both germination and vegetative growth. Possible effects due to location were also examined by conducting tests at two different sites. Significant variations in biostimulant response were evident only during the germination period, but not during the vegetative development stage, where the observed statistical differences were influenced more by the location or variety of chickpeas employed. Furthermore, this study examined the effect of biostimulants on nutrient cycling within the soil-plant microbiota system. Nitrogen-fixing bacteria (NFB) are present in the soil of chickpea crops at an order of magnitude of 107 CFU/g DS. Additionally, an average concentration of 106 CFU/g DS of phosphorus-mobilising bacteria was observed. Applying biostimulants (BioE) to seeds resulted in a successful germination percentage (GP) for both Amelia (AM) and IMIDRA 10 (IM) varieties.

The Effects of Legacy Sediment Removal and Floodplain Reconnection on Riparian Plant Communities

Stream restoration includes a number of different approaches intended to reduce sediment and nutrient export. Legacy sediment removal (LSR) and floodplain reconnection (FR) involve removing anthropogenically derived sediment accumulated in valley bottoms to reconnect incised streams to their floodplains. These projects also present an opportunity to create high-quality riparian and wetland plant communities and provide information about the early stages of wetland vegetation development and succession. We surveyed vegetation immediately after restoration at three sites and at three additional sites 1–3 years post-restoration to determine how LSR/FR affects riparian plant communities. Restoration increased the prevalence of hydrophytic herbaceous species at all sites, suggesting these projects successfully reconnected the stream to the floodplain. Pronounced decreases in woody basal area and stem density likely also influenced an increase in native and graminoid species after restoration. Only 16% of the indicator species identified for restored reaches were planted as part of the restoration, suggesting the local seed bank and other seed sources may be important for vegetation recovery and preservation of regional beta diversity. Although vegetation quality increased after restoration in reaches with initially low-quality herbaceous vegetation, vegetation quality did not improve or decreased after restoration in reaches with higher-quality vegetation before restoration. The practice of LSR/FR has the potential to improve the quality of some riparian vegetation communities, but the preservation of high-quality forested areas, even if they are atop legacy sediment terraces, should be considered, particularly if reductions in nutrient export do not offset losses in tree canopy.

Botanical Leaf Extracts and Mulching Materials in Organic Eggplant (Solanum Melongena L.) Off Season Production

The extensive use of pesticides and the risk they pose to human and the environment requires safe alternatives in crop production hence the study on the efficacy of botanical leaf extracts and mulching materials in organic eggplant production. This study determined the best level combination of botanical leaf extracts that has repellent and knockdown effects on major eggplant insect pest, best level combination of botanical leaf extracts that produces the highest marketable yield; best mulching materials; best level combination of botanical leaf extracts and mulching; correlation of infestation to yield; profitability of eggplant production using botanical leaf extracts and mulching materials combined; and evaluate the effects of botanical leaf extracts and mulching materials on soil chemical properties. A Bioassay test on the botanical leaf extracts was conducted prior to field experiment. Mass rearing the test insects was done to ensure uniform number of insect in eggplant per treatment. A Split- plot in Factorial Design was used in the study with three blocks. The main plot were the leaf extracts of Neem, Madre de Cacao+ Guava at 1:1:1 ratio were: P0 – No Application, P1 –250 ml leaf extract/16 li water, P2 –500 ml leaf extract /16 li water, P3 –750 ml leaf extract /16 li water, P4 – 40 ml Commercial insecticide/16 li water. The sub-plot was: M1 – Black Plastic mulch, M2 – Carbonize Rice Hulls, and M3 – Saw Dust. Results of the bioassay showed highly significant knockdown effect in the application of 500-750ml leaf extract/16 li water on fruit and shoot borer, lady spotted beetle and white flies comparable to application of commercial insecticide/16 li water. Significant repellent effects on Fruit Shoot Borer and Lady spotted beetles but no repellent effects on white flies for an application of 250ml botanical leaf extracts/16li water. Results under field condition showed that plants applied with 750ml botanical leaf extracts/16 li water is more effective than commercial insecticide/16 li water in reducing damaged leaves during the early vegetative stage of development (2nd WAT) and at reproductive stage of development (10th WAT). Highly significant difference was obtained in terms in weight of non-marketable fruit. No significant interaction was registered between botanical leaf extracts and mulching materials. Regression correlation analysis revealed that there was a direct correlation between the numbers of damaged leaves to yield. Combined application of botanical leaf extracts at 750ml/16 li water + carbonized rice hulls obtained Php 797,635.15 net for organic off-season eggplant production. Soil pH, OM, P, and K were increased with application of sawdust, carbonized rice hulls and plastic mulch.

Polyploidy in the history of breeding at the Yaltushkiv Experimental Breeding Station: new methods of differentiation and stabilisation of sugar beet tetraploids

Purpose. To analyse the history of the polyploid breeding at the Yaltushkiv Experimental Breeding Station, in particular the improvement of genetic models of new hybrids, new methods of induction of meiotic tetraploids, differentiation and selection of breeding genotypes by genome ploidy.
 Methods. Cytological analysis of metaphase chromosomes of the apical meristems of the growth points of seed plants and beets of the first year for the selection of tetraploid plants 4x = 36 chromosomes; cytophotometric analysis using computer programs AP Partec to study ploidy based on the quantitative content of nuclear DNA; field methods (selection of tetraploid seed plants according to the types of pollen grains, formation of synthetic populations of tetraploid multigerm plants on a cytogenetic basis according to the structure of bivalent conjugation of homologous chromosomes in meiosis.
 Results. In the process of tetraploid induction, cytological methods of ploidy analysis at the station were improved using computer programs of AP Partec for the selection of sugar beets 4x by the quantitative content of nuclear DNA in the cell on plants of the first year of vegetation and for the formation of tetraploid populations after colchicine induction in seed plants. In the process of studying the structure of polyploid populations by ploidy, the percentage of tetraploids varied from 82.0±2.22% in Ya/Hen pollinator to 58.1±2.81% in Ya/Man pollinator. It was established that the selection for fertility and pollen uniformity depends on the genetic characteristics of the breeding genotypes and affects the pollen-forming ability in the first generations after induction with colchicine, reducing the number of 4x IIa and IIb biotypes according to cytological classification. Using the example of the multigerm pollinator Ya/Roi, it was established that selection for sugar content and productivity had, to a certain extent, a stabilising effect on the degree of ploidy. The biotechnological methods used to deposit 4x genotypes with a high percentage of bivalent conjugation of homologous chromosomes in metaphase I of meiosis (70–90%) contributed to the cytogenetic stability of polyploid gametes and their high yield – 92.9% of 4x in the next generation of seeds. It was investigated that the productivity of triploid hybrids obtained with the use of the tetraploid pollinator Ya/DA 4x based on the germplasm of the wild species Beta patula at the early stages of vegetative development varied in triploid plants from 325 to 465 g, and the sugar content in some numbers reached 21.5%.
 Conclusions. The development of polyploid selection at the Yaltushkiv Experimental Breeding Station evolved from the development polyhybrids to the development of triploid hybrids based on CMS using tetraploid multigerm pollinators. For the formation of populations of tetraploid multigerm pollinators, the methods of fluorescent cytophotometry and computer programs AP Partec were used, as well as biotechnological methods for creating synthetic populations of tetraploid multigerm pollinators on a cytogenetic basis, which ensure the yield of tetraploids in seeds up to 92.9%.

Effect of Spraying with Humic Acid and Active Yeast Suspension on the Growth Indicators and Active Substances of Calendula officinalis L.

The purpose of this study was to examine the impact of spraying C. officinalis L. with Humic acid and active yeast suspension on growth indicators for both the vegetative and floral stages of development. Humic acid was sprayed on the plants in varying quantities (0, 2, or 4 g) in a factorial experiment with 9 treatments (two factors overlapped). and a suspension of live yeast at 3, 6, or 0 mg/L-1, and the treatment consisted of three sprays, with a 15-day gap between each application. Using a Factorial Experiment with three replicates and three plants per experimental unit, I compared means at the 5% probability level using the Revised Least Significant Differences (R.L.S.D.) test. The most significant findings, in her opinion, are as follows: Humic acid spraying at a dosage of 4 mg/L-1. While this concentration greatly slowed flowering, L-1 significantly increased plant height, number of lateral branches, percentage of dry matter of shoot, number of flowers, number of petals, flower diameter, flower stand length, and percentage of dry matter in flowers. The greatest concentration, 6 mg.L-1, was achieved through spraying with an active yeast suspension. Although this concentration greatly slowed flowering enhanced plant height, lateral branching, leaf count, flower count, petal count, flower diameter, and floral dry matter percentage. There was a statistically significant impact on all attributes measured by the binary interactions.

The Effects of Rhizophagus irregularis Inoculation on Transcriptome of Medicago lupulina Leaves at Early Vegetative and Flowering Stages of Plant Development.

The study is aimed at revealing the effects of Rhizophagus irregularis inoculation on the transcriptome of Medicago lupulina leaves at the early (second leaf formation) and later (flowering) stages of plant development. A pot experiment was conducted under conditions of low phosphorus (P) level in the substrate. M. lupulina plants were characterized by high mycorrhizal growth response and mycorrhization parameters. Library sequencing was performed on the Illumina HiseqXTen platform. Significant changes in the expression of 4863 (padj < 0.01) genes from 34049 functionally annotated genes were shown by Massive Analysis of cDNA Ends (MACE-Seq). GO enrichment analysis using the Kolmogorov-Smirnov test was performed, and 244 functional GO groups were identified, including genes contributing to the development of effective AM symbiosis. The Mercator online tool was used to assign functional classes of differentially expressed genes (DEGs). The early stage was characterized by the presence of six functional classes that included only upregulated GO groups, such as genes of carbohydrate metabolism, cellular respiration, nutrient uptake, photosynthesis, protein biosynthesis, and solute transport. At the later stage (flowering), the number of stimulated GO groups was reduced to photosynthesis and protein biosynthesis. All DEGs of the GO:0016036 group were downregulated because AM plants had higher resistance to phosphate starvation. For the first time, the upregulation of genes encoding thioredoxin in AM plant leaves was shown. It was supposed to reduce ROS level and thus, consequently, enhance the mechanisms of antioxidant protection in M. lupulina plants under conditions of low phosphorus level. Taken together, the obtained results indicate genes that are the most important for the effective symbiosis with M. lupulina and might be engaged in other plant species.

The Fungal Root Endophyte Serendipita indica (Piriformospora indica) Enhances Bread and Durum Wheat Performance under Boron Toxicity at Both Vegetative and Generative Stages of Development through Mechanisms Unrelated to Mineral Homeostasis.

While the importance of beneficial soil microorganisms for soil health and crop performance has been receiving ever-increasing attention, Serendipita indica has been widely studied as a fungal root endophyte with significant potential for increasing the stress tolerance of host plants. Boron (B) toxicity as an adverse soil condition is particularly prevalent in arid and semi-arid regions and threatens crop production. Studies on S. indica-wheat symbiosis are limited, and effects of S. indica on crops have never been reported in the context of B toxicity. Here, two pot experiments were conducted under greenhouse conditions to investigate the effects of S. indica on the growth and yield parameters of bread (Triticum aestivum) and durum wheat (Triticum durum) grown at different levels of B toxicity in native vs. sterilized soil, and parameters related to root colonization, membrane damage, oxidative stress, chlorophyll, and mineral nutrition were measured to elucidate the physiological mechanisms of damage and benefit. Boron toxicity decreased early vegetative growth and grain yield, but it did not affect the straw dry weight of mature plants, whereas S. indica significantly enhanced the vegetative growth, straw dry weight, and the grain number of both wheat species. Membrane damage as demonstrated by increased lipid peroxidation and relative electrolyte leakage was caused by B toxicity and alleviated by S. indica. The benefits provided by S. indica could not be attributed to any significant changes in tissue concentrations of B or other minerals such as phosphorus. Soil sterilization generally improved plant performance but it did not consistently strengthen or weaken the effects of S. indica. The presented results suggest that S. indica may be used as an effective microbial inoculant to enhance wheat growth under adverse soil conditions such as B toxicity through mechanisms that are possibly unrelated to mineral homeostasis.

Phospholipid:diacylglycerol acyltransferase1-overexpression stimulates lipid turnover, oil production and fitness in cold-grown plants

BackgroundExtensive population growth and climate change accelerate the search for alternative ways of plant-based biomass, biofuel and feed production. Here, we focus on hitherto unknow, new promising cold-stimulated function of phospholipid:diacylglycerol acyltransferase1 (PDAT1) – an enzyme catalyzing the last step of triacylglycerol (TAG) biosynthesis.ResultOverexpression of AtPDAT1 boosted seed yield by 160% in Arabidopsis plants exposed to long-term cold compared to standard conditions. Such seeds increased both their weight and acyl-lipids content. This work also elucidates PDAT1’s role in leaves, which was previously unclear. Aerial parts of AtPDAT1-overexpressing plants were characterized by accelerated growth at early and vegetative stages of development and by biomass weighing three times more than control. Overexpression of PDAT1 increased the expression of SUGAR-DEPENDENT1 (SDP1) TAG lipase and enhanced lipid remodeling, driving lipid turnover and influencing biomass increment. This effect was especially pronounced in cold conditions, where the elevated synergistic expression of PDAT1 and SDP1 resulted in double biomass increase compared to standard conditions. Elevated phospholipid remodeling also enhanced autophagy flux in AtPDAT1-overexpresing lines subjected to cold, despite the overall diminished autophagy intensity in cold conditions.ConclusionsOur data suggest that PDAT1 promotes greater vitality in cold-exposed plants, stimulates their longevity and boosts oilseed oil production at low temperature.

Response of peanut (Arachis hypogaea L.) to sublethal rates of dicamba plus glyphosate at different growth stages

AbstractThe widespread adoption of dicamba‐resistant crops has increased the applications of newer dicamba formulations for weed control. However, there is a concern for potential off‐target injury and yield reduction to peanuts (Arachis hypogea L.) planted in close proximity to dicamba‐resistant crops. Field experiments were conducted in the summer of 2019 and 2020 to evaluate peanut response to reduced rates (1/512X, 1/128X, 1/32X, and 1/8X the label rate, 564 + 1280 g ae ha−1) of dicamba plus glyphosate (XtendiMax plus Roundup PowerMax) at 25, 50, and 75 days after planting (DAP) which corresponds to vegetative, flowering, and pod development stages, respectively. Peanut exposure to dicamba plus glyphosate at 25 DAP resulted in 1.6–2.3 times greater injury and 3.4–8.5 times greater height and canopy width reductions compared to 50 and 75 DAP exposures. Peanuts suffered greater yield reduction (18%–19%) when exposed to dicamba plus glyphosate at 25 and 75 DAP than at 50 DAP (10%). Regression analysis indicated a significant linear response for peanut injury (except at 8 weeks after treatment), canopy width reduction, and yield reduction with an increasing rate of dicamba plus glyphosate. Dicamba plus glyphosate at 1/512X rate resulted in a 3% peanut yield reduction, whereas a 41% yield reduction was observed at 1/8X rate. Correlation analysis, with Pearson's rho values ranging from 0.81 to 0.86, showed that peanut injury can be a useful predictor for estimating yield reduction. Therefore, extreme care must be taken to prevent drift occurrence or spray‐tank contamination when applying dicamba plus glyphosate on XtendFlex crops near peanut fields.

Light interception and radiation use efficiency in quinoa (Chenopodium quinoa Willd.)

AbstractQuinoa (Chenopodium quinoa Willd.) is an annual plant belonging to the Amaranthaceae family. The total accumulated incident photosynthetic active radiation (PAR) in a plant is a function of the site, year, sowing date, and phenology, whereas the amount of PAR intercepted by the plant is dependent on its leaf area index (LAI) and light extinction coefficient (KPAR). This study investigated changes in KPAR and radiation use efficiency (RUE) levels in quinoa before and after inflorescence (fruit set) color change under various temperature and light conditions through the sowing date. This study was conducted in the Jihad Keshavarzi allocated field of Khalilabad city in Khorasan Razavi province, Iran, using a randomized complete block design with three replications over two seasons, 2017–2018 and 2018–2019. Treatments included eight and seven sowing dates in the first and second season years, respectively. The results showed that the mean of KPAR was 0.66 and 0.31 in the first and second years, respectively. Also RUE in vegetative stages of development was higher than during the grain‐filling period. The mean of RUE was 2.60 ± 0.06 and 0.78 ± 0.17g/MJ in the first year before and after changing the color of the inflorescence (fruit set), respectively; these values were 2.12 ± 0.04 and 1.01 ± 0.61 g/MJ in the second year. The results indicated the base (TBRUE), lower optimum (TP1RUE), upper optimum, and ceiling temperatures of quinoa for RUE were determined to be 3, 18.8, 25.5, and 35°C, respectively.

Nitrogen Use Efficiency Regulates Drought Stress in Pearl Millet Genotypes: Morpho-Physiological Evaluation

In this paper, the author discusses the effects of drought stress on pearl millet genotypes during the vegetative stage of development and the plant’s mechanisms for survivability under stress with various nitrogen treatment regimes. A total of six treatment conditions were imposed on plants, i.e., N0 (no Nitrogen-0 mM), N0+PEG-10%, LN (low Nitrogen-2.5 mM), LN+PEG-10%, HN (high Nitrogen-7.0 mM), and HN+PEG-10%. Five days of moderate drought stress caused significant morphophysiological changes, as evidenced by a reduction in fresh and dry biomass, as well as relative water content (RWC), relative electrolyte leakage, and chlorophyll fluorescence,. A significant reduction in plant biomass and RWC when compared to the controls was seen. Reactive oxygen species (ROS) and lipid peroxidation (MDA) levels increased in the shoot in response to drought stress along with a loss of membrane integrity. A nitrogen treatment regime regulated the drought stress. In relation to N0-treated batches, proline accumulation increased in various N-treated batches. Results revealed that GHB-538 is less tolerant to drought stress in different N treatment conditions, while RHB-234 and 223 showed better tolerance to drought under nitrogen treatments. The significance of this study is to uncover the regulatory role of nitrogen over the drought stress in pearl millet.

Distribution of Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae) and incidence of maize rayado fino virus and Candidatus Phytoplasma asteris in corn succession planting systems.

Corn is one of the main crops grown globally to produce food for human consumption and animal feed, including raw materials for bioenergy. Effective pest management is critical for the economic viability of corn production. The leafhopper Dalbulus maidis and the diseases transmitted by it have become relevant to corn production. Our study aimed to determine environmental parameters that affect D. maidis populations and the impacts of pathogen dispersion on corn productivity under different rotation systems and sowing seasons. The population density of leafhoppers found in the studied crops was low but capable of establishing the diseases and spreading them widely in the crops. The leafhopper's highest occurrence was in the corn vegetative development stage, and its population peaks were earlier in the corn off-season. The incidence of maize rayado fino virus and maize bushy stunt phytoplasma were higher in corn off-season than in the growing season. The incidence of diseases was higher in the final stages of the cultivation cycle. Yield losses were significantly higher for maize bushy stunt phytoplasma and not significant for maize rayado fino virus. Our study observed that corn's physiological stage was the main factor influencing D. maidis dynamics. The occurrence of D. maidis at low densities was sufficient to ensure the efficient transmission and dissemination of maize rayado fino virus and maize bushy stunt phytoplasma, which had a higher incidence in the reproductive stage and the corn sowed off-season. © 2023 Society of Chemical Industry.

Rhizobacteria-Based Biostimulant Mixture Effect on Chickpea (Cicer arietinum L.) in Greenhouse and Cultivation Assays

This study aims to contribute to the improvement of the chickpea agri-food industry and adapt it to future challenges. For this, the effect of a Rhizobacteria-based biostimulant mixture was analyzed in Amelia variety of chickpea (Cicer arietinum L.) in two different experiments: one in flowerpots in a greenhouse and the other one in the field grown under rainfed conditions. Germination success, vegetative development and phenological stages of the plants were studied after applying liquid biostimulant mixture on the seeds 24 h before sowing or spraying it on the soil after sowing. The results indicated that the way of application of the biostimulant was relevant concerning germination success, vegetative development, and phenological state of chickpea plants and it should be adapted to intensive agriculture with the use of seed drill that requires dry seeds. Regarding germination success, vegetative development and phenological stages in the flower pot assay, the volume of biostimulant mixture applied to the seeds was remarkable as higher volumes affected negatively while lower volumes were positive. Biostimulant had a negative effect on the development of chickpea plants in the field assay, probably because it also promoted the growth of weeds, which lessened the growth of the chickpea plants.

Peanut response to 2,4-D plus glyphosate

AbstractThe commercialization of crops that are resistant to 2,4-D plus glyphosate provided an opportunity to growers to apply the herbicide postemergence. However, the potential drift injury of these herbicides to peanuts grown near crops that are resistant to 2,4-D plus glyphosate is concerning. Field experiments were conducted in 2019 and 2020 to evaluate peanut response when exposed at 25, 50, and 75 d after planting (DAP) corresponding to vegetative, flowering, and pod development stages, respectively, to reduced rates of 1/512×, 1/128×, 1/32×, and 1/8× of the labeled rate of 2,4-D plus glyphosate (i.e., 1,077 + 1,132 g ae ha−1, respectively). 2,4-D plus glyphosate was more injurious to peanuts when exposed at 25 DAP compared with 50 and 75 DAP. Similarly, greater canopy height (12%) and canopy width (16%) reductions were observed at 25 DAP compared with 50 and 75 DAP exposure timings (3% to 9%). This result indicates that peanut is more sensitive to 2,4-D plus glyphosate exposure at the vegetative growth stage than at the flowering and pod development stages. However, yield reductions (13% to 16%) were not different between 25, 50, or 75 DAT exposure timings. Regression analysis indicated a linear response for peanut injury, canopy height, width, and yield reduction with an increasing rate of 2,4-D plus glyphosate. The highest rate of 2,4-D plus glyphosate (1/8× of the label rate) resulted in 38%, 22%, and 23% peanut injury, canopy height, and width reduction at 4 wk after treatment, and 33% yield reduction. There was a correlation between peanut injury and yield reduction, with Pearson’s rho values ranging from 0.70 to 0.73. The findings suggest that peanut injury rating data after 2,4-D plus glyphosate drift can be useful for estimating potential yield losses.

Comprehensive Transcriptome Profiling Uncovers Molecular Mechanisms and Potential Candidate Genes Associated with Heat Stress Response in Chickpea.

Chickpea (Cicer arietinum L.) production is highly susceptible to heat stress (day/night temperatures above 32/20 °C). Identifying the molecular mechanisms and potential candidate genes underlying heat stress response is important for increasing chickpea productivity. Here, we used an RNA-seq approach to investigate the transcriptome dynamics of 48 samples which include the leaf and root tissues of six contrasting heat stress responsive chickpea genotypes at the vegetative and reproductive stages of plant development. A total of 14,544 unique, differentially expressed genes (DEGs) were identified across different combinations studied. These DEGs were mainly involved in metabolic processes, cell wall remodeling, calcium signaling, and photosynthesis. Pathway analysis revealed the enrichment of metabolic pathways, biosynthesis of secondary metabolites, and plant hormone signal transduction, under heat stress conditions. Furthermore, heat-responsive genes encoding bHLH, ERF, WRKY, and MYB transcription factors were differentially regulated in response to heat stress, and candidate genes underlying the quantitative trait loci (QTLs) for heat tolerance component traits, which showed differential gene expression across tolerant and sensitive genotypes, were identified. Our study provides an important resource for dissecting the role of candidate genes associated with heat stress response and also paves the way for developing climate-resilient chickpea varieties for the future.

ALLELOPATHIC IMPACT OF AQUEOUS LEACHATE OF EUCALYPTUS GLOBULUS L. LEAVES ON SEED GERMINATION, GROWTH, AND BIOCHEMICAL CONTENTS OF SEEDLING OF ELEUSINE CORACANA GAERTN

The background to the study: Allelopathy can be distinguished from other plant interference strategies because the donor species produces inhibitory compounds into the environment to cause harm. This work aimed to evaluate the allelopathic impact of aqueous leachate of Eucalyptus globulus leaf litter on seed germination, biochemical, and growth parameters of finger millet (Eleusine coracana) seedlings. Methods: This experiment was conducted using aqueous leaf litter leachate at a concentration of 100%, 80%, 60%, 40%, and 20% using water as a control. Results: The experiment showed that all the test concentrations of leachate had a deleterious effect on seed germination, seedling growth-like length, fresh and dry weight, and biochemical parameters such as total chlorophyll and total carbohydrate of the test crop, Eleusine coracana seedlings. Further, it was also observed that the inhibitory effects were gradually increased with a rise in the leaf leachate concentration. Conclusion: It is recommended that crops not be associated with different species of Eucalyptus due to the allelopathic influence on germination and early vegetative developmental stages of crops.

Структура растительных сообществ сукцессионных стадий на торфяниках, нарушенных фрезерной добычей торфа (на примере карбонового полигона «Росянка» в Калининградской области)

Nine plant community types were identified in the central part of the Vittgirrensky Peat­land (designated the Rossyanka Carbon Supersite). All community types represent succes­sional stages of vegetation development on areas transformed by peat milling. Data on the structure and species composition of communities are provided, along with typical phytoso­ciological descriptions for each vegetation variant. Physiognomically, the plant communities on the milled fields consist of low-stature tree stands with varying canopy closure, mainly dominated by Betula pendula, but they exhibit substantial differences in the composition of herb-shrub and moss cover. The described community types are considered as non-hierarchical units in the classification of vegetation cover (at the micro-landscape level). Their identification through electronic and field mapping methods allows for a rapid visualization of the vegetation cover's characteristics on a map and enables its quantitative assessment, which is of practical importance for the purposes of the carbon supersite.