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20 pages, 1379 KiB  
Article
Combined Effects of Polyethylene and Bordeaux Mixture on the Soil–Plant System: Phytotoxicity, Copper Accumulation and Changes in Microbial Abundance
by Silvia Romeo-Río, Huguette Meta Foguieng, Antía Gómez-Armesto, Manuel Conde-Cid, David Fernández-Calviño and Andrés Rodríguez-Seijo
Agriculture 2025, 15(15), 1657; https://doi.org/10.3390/agriculture15151657 - 1 Aug 2025
Abstract
Greenhouses have positively impacted plant production by allowing the cultivation of different crops per year. However, the accumulation of agricultural plastics, potentially contaminated with agrochemicals, raises environmental concerns. This work evaluates the combined effect of Bordeaux mixture and low-density polyethylene (LDPE) microplastics (<5 [...] Read more.
Greenhouses have positively impacted plant production by allowing the cultivation of different crops per year. However, the accumulation of agricultural plastics, potentially contaminated with agrochemicals, raises environmental concerns. This work evaluates the combined effect of Bordeaux mixture and low-density polyethylene (LDPE) microplastics (<5 mm) on the growth of lettuce (Lactuca sativa L.) and soil microbial communities. Different levels of Bordeaux mixture (0, 100 and 500 mg kg−1), equivalent to Cu(II) concentrations (0, 17 and 83 mg kg−1), LDPE microplastics (0, 1% and 5%) and their combination were selected. After 28 days of growth, biometric and photosynthetic parameters, Cu uptake, and soil microbial responses were evaluated. Plant germination and growth were not significantly affected by the combination of Cu and plastics. However, individual Cu treatments influenced root and shoot length and biomass. Chlorophyll and carotenoid concentrations increased with Cu addition, although the differences were not statistically significant. Phospholipid fatty acid (PLFA) analysis revealed a reduction in microbial biomass at the highest Cu dose, whereas LDPE alone showed limited effects and may reduce Cu bioavailability. These results suggest that even at the highest concentration added, Cu can act as a plant nutrient, while the combination of Cu–plastics showed varying effects on plant growth and soil microbial communities. Full article
(This article belongs to the Special Issue Impacts of Emerging Agricultural Pollutants on Environmental Health)
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18 pages, 1182 KiB  
Article
Effects of Remote Barley Seed Treatment with Weak Non-Thermal Pulsed Electromagnetic Fields on Plant Development and Yields
by Igor F. Turkanov, Elena V. Bondarchuk, Valery G. Gryaznov, Ekaterina A. Galkina, Alexey Yu. Guzenko, Vladimir G. Zainullin, Elena G. Kozar and Irina M. Kaigorodova
Seeds 2025, 4(3), 35; https://doi.org/10.3390/seeds4030035 - 18 Jul 2025
Viewed by 302
Abstract
Numerous scientific studies have confirmed the effectiveness of seed bioactivation using electromagnetic fields (EMFs) in agriculture. This article presents the results of the remote application of an EMF TOR device in the cultivation of barley Hordeum vulgare L. Laboratory studies and field tests [...] Read more.
Numerous scientific studies have confirmed the effectiveness of seed bioactivation using electromagnetic fields (EMFs) in agriculture. This article presents the results of the remote application of an EMF TOR device in the cultivation of barley Hordeum vulgare L. Laboratory studies and field tests were conducted, showing a positive effect on the growth and development of plants both when treating dry seeds before sowing and when treating sown seeds in the field. The optimal time period for EMF treatment was determined: treating air-dried seeds with EMFs before sowing for 10–15 min increased germination by 5–18% and the growth rate of seedlings by 2–3 times. The maximum observed effect occurred during the treatment period from 7:00 to 11:00. As a result of changing the balance of phytohormones, the further stimulation of the root system and the assimilation surface of plants was noted due to a 1.5-fold increase in the content of auxins. The density of productive stems, ear length, seed set, and 1000 seed weight increased, which ultimately led to an increase in yield by more than 10% and, in some varieties, to a decrease in the protein content in grains compared to the control variant (by 3–22%), bringing them closer to brewing conditions. Full article
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21 pages, 5488 KiB  
Article
Germinated Spores of the Probiotic Bacterium Bacillus coagulans JBI-YZ6.3 Support Dynamic Changes in Intestinal Epithelial Communication and Resilience to Mechanical Wounding
by Sage V. McGarry, Earvin A. F. Grinage, Krista Sanchez, Dina Cruickshank, Liang Anderson and Gitte S. Jensen
Microorganisms 2025, 13(7), 1466; https://doi.org/10.3390/microorganisms13071466 - 24 Jun 2025
Viewed by 893
Abstract
The spore-forming probiotic Bacillus coagulans JBI-YZ6.3 interacts with the gut epithelium via its secreted metabolites as well as its cell walls, engaging pattern-recognition receptors on the epithelium. We evaluated its effects on human T84 gut epithelial cells using in vitro co-cultures, comparing metabolically [...] Read more.
The spore-forming probiotic Bacillus coagulans JBI-YZ6.3 interacts with the gut epithelium via its secreted metabolites as well as its cell walls, engaging pattern-recognition receptors on the epithelium. We evaluated its effects on human T84 gut epithelial cells using in vitro co-cultures, comparing metabolically active germinated spores to the isolated metabolite fraction and cell wall fraction under unstressed versus inflamed conditions. Germinated spores affected epithelial communication via chemokines interleukin-8, interferon gamma-induced protein-10, and macrophage inflammatory protein-1 alpha and beta after 2 and 24 h of co-culture. Non-linear dose responses confirmed that bacterial density affected the epigenetic state of the epithelial cells. In contrast, the cell wall fraction increased cytokine and chemokine levels under both normal and inflamed conditions, demonstrating that the intact bacterium had anti-inflammatory properties, regulating pro-inflammatory signals from its cell walls. During recovery from mechanical wounding, germinated spores accelerated healing, both in the absence and presence of LPS-induced inflammation; both the metabolite and cell wall fractions contributed to this effect. The release of zonulin, a regulator of tight junction integrity, was reduced by germinated spores after 2 h. These findings suggest that B. coagulans JBI-YZ6.3 modulates epithelial chemokine signaling, supports barrier integrity, and enhances epithelial resilience, highlighting its potential as an efficacious multi-faceted probiotic for gut health. Full article
(This article belongs to the Special Issue Advances in Host-Gut Microbiota)
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17 pages, 744 KiB  
Article
Effect of Plant Density on Artemisia annua L. Biomass and Essential Oil Yield and Its Weed Seed Germination Suppression
by Flavio Polito, Michele Denora, Donato Casiello, Pierluigi Casiero, Loriana Cardone, Vincenzo Candido, Michele Perniola, Vincenzo De Feo, Valentino Palombo and Sebastiano Delfine
Agriculture 2025, 15(13), 1330; https://doi.org/10.3390/agriculture15131330 - 20 Jun 2025
Viewed by 427
Abstract
During spring–summer 2023 and 2024, an Artemisia annua crop was carried out, using two planting densities (20D = 5.0 plants m−2; 40D = 2.5 plants m−2). Morphological traits were measured, including height, stem number, diameter, weight, and dry above-ground [...] Read more.
During spring–summer 2023 and 2024, an Artemisia annua crop was carried out, using two planting densities (20D = 5.0 plants m−2; 40D = 2.5 plants m−2). Morphological traits were measured, including height, stem number, diameter, weight, and dry above-ground biomass. The aerial parts were hydro-distilled, and the essential oil (EO) yield increased from the 1st to 2nd year, from 0.117 to 0.439% for 20D and from 0.157 to 0.550% for 40D. There were significant variations in chemical composition between the years, with an increase in the presence of oxygenated monoterpenes in the 2nd year and the disappearance of oxygenated sesquiterpenes. In the 1st year, sesquiterpene hydrocarbons were the main class, while in the 2nd, oxygenated monoterpenes predominated. The main components were artemisia ketone (8.05–65.77%), eucalyptol (4.70–13.14%), and β-selinene (5.38–37.53%), present in all the EOs, and trans-caryophyllene (11.65%), present only in the 1st year EOs. The possible phytotoxicity of the EOs on seeds of plants found in the A. annua crops was evaluated. The most susceptible seeds were Sinapis alba, Papaver rhoeas, and Portulaca oleracea. The phytotoxicity was greater in the 2nd year, with more marked effects on the germination of P. rhoeas and P. oleracea (up to 100%). The inhibition of root elongation reached 100% for those at the higher concentrations tested. Full article
(This article belongs to the Section Crop Production)
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17 pages, 2283 KiB  
Article
Sowing in Plastic Contaminated Soils: How (Micro)plastics Impact Seed Germination and Growth of White Mustard (Sinapis alba L.)
by Špela Železnikar, Nina Kacjan Maršić and Marina Pintar
Appl. Sci. 2025, 15(12), 6801; https://doi.org/10.3390/app15126801 - 17 Jun 2025
Viewed by 289
Abstract
Microplastic (MP) particles are ubiquitous in the environment and pose a growing threat to ecosystem stability. As concern over their ecological impact increases, biotests and ecotoxicological approaches using plant species have become valuable tools for research. This study aimed to evaluate the effects [...] Read more.
Microplastic (MP) particles are ubiquitous in the environment and pose a growing threat to ecosystem stability. As concern over their ecological impact increases, biotests and ecotoxicological approaches using plant species have become valuable tools for research. This study aimed to evaluate the effects of varying concentrations of low-density polyethylene (LDPE) MP on seed germination, root development, and shoot growth of white mustard (Sinapis alba L.) under controlled laboratory and pot experiment conditions. For the seven-day laboratory experiment, concentrations of 0.01% and 1% w/w were used, whereas concentrations of 1% and 5% w/w were applied in the ten-day pot experiment. Results indicated no statistically significant effects of LDPE MP on germination rate or germination speed index (GSI) in either setting. However, shoot length data suggest that the 5% LDPE treatment may have a slight stimulatory effect compared to the control, though this trend was marginally significant. These findings highlight the complex and context-dependent nature of MP–plant interactions. Further research is needed to better understand the mechanisms driving these responses and to support the development of mitigation strategies for MP contamination in terrestrial ecosystems. Full article
(This article belongs to the Special Issue Advanced Research on Microplastics, Human Exposure and Food Safety)
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16 pages, 599 KiB  
Article
Toxicity Assessment of Catechins on Representative Aquatic Organisms and Terrestrial Plant
by Khawaja Muhammad Imran Bashir, Hye-Ryeon An, Bertoka Fajar Surya Perwira Negara, Gabriel Tirtawijaya, Maria Dyah Nur Meinita, Jae-Hak Sohn, Dicky Harwanto and Jae-Suk Choi
Toxins 2025, 17(5), 244; https://doi.org/10.3390/toxins17050244 - 14 May 2025
Cited by 1 | Viewed by 615
Abstract
Catechins, renowned for their health benefits, have unexamined environmental impacts. This study assessed the toxicity of crude catechin and catechin hydrate on invertebrate larvae, plant, and microalgae. The survival rates of Daphnia magna Straus and Artemia salina L. were monitored every 24 h [...] Read more.
Catechins, renowned for their health benefits, have unexamined environmental impacts. This study assessed the toxicity of crude catechin and catechin hydrate on invertebrate larvae, plant, and microalgae. The survival rates of Daphnia magna Straus and Artemia salina L. were monitored every 24 h over a three-day period. The germination rate and radicle length of Lactuca sativa L. was measured every 24 h for four days. Inhibitory effects were evaluated in both freshwater and seawater cultures of Chlorella vulgaris Beijerinck, with cell density recorded every 24 h and yield inhibition calculated after 96 h. Results indicated that increasing catechin concentration and exposure duration decreased the survival rate of D. magna and A. salina. Daphnia magna was more sensitive to catechins than A. salina, with 24 h lethal concentration 50 (LC-50) values of 1174 µg/mL compared to 1895 µg/mL for crude catechin, and 54 µg/mL compared to 153 µg/mL for catechin hydrate. The germination rate and radicle length of L. sativa, along with the cell density of C. vulgaris, decreased with increasing catechin concentration, but remained higher even after prolonged exposure. At low catechin concentrations, C. vulgaris cell density exceeded control levels. This study demonstrates that catechins in aquatic environments can significantly impact ecosystems. At certain concentrations, catechins are toxic and potentially lethal to aquatic organisms. Conversely, at lower concentrations, catechins may promote microalgal growth, suggesting a fertilizing effect. Understanding these dynamics is crucial for maintaining the stability of aquatic ecosystems. Full article
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18 pages, 5784 KiB  
Article
Application of Gellan Hydrogel and Kaz-6 in Wheat Seed Coating for Improved Productivity and Environmental Resilience
by Bagila Tursynova, Tolganay Zharkynbek, Rauash Mangazbayeva, Nurzhan Mukhamadiyev, Raushan Koizhaiganova, Gulnaz Mengdibayeva, Assel Ten, Bayana Yermukhambetova, Grigoriy Mun and Valentina Yu
Polymers 2025, 17(10), 1330; https://doi.org/10.3390/polym17101330 - 14 May 2025
Viewed by 564
Abstract
Drought is a major environmental constraint that negatively affects crop germination, seedling establishment, and overall yield. This study presents a sustainable approach to improving wheat productivity under water-deficit conditions through the application of a gellan gum-based hydrogel enriched with the growth stimulant. The [...] Read more.
Drought is a major environmental constraint that negatively affects crop germination, seedling establishment, and overall yield. This study presents a sustainable approach to improving wheat productivity under water-deficit conditions through the application of a gellan gum-based hydrogel enriched with the growth stimulant. The hydrogel was synthesized by inducing ionic gelation of gellan gum using potassium chloride and ammonium sulfate, forming a robust, cross-linked polymer network. Wheat seeds were coated with one to eight layers of the hydrogel using a sequential dipping and drying process. Optimal seedling performance was achieved with a two-layer coating, balancing sufficient water retention with adequate gas exchange. FTIR spectroscopy and pH analysis confirmed ionic interactions between Kaz-6 and the carboxyl groups of gellan, supporting its stable incorporation within the polymer matrix. Mechanical characterization showed that ammonium sulfate significantly enhanced gel strength and cross-linking density compared to potassium chloride. Laboratory germination assays and greenhouse trials demonstrated that seeds coated with gellan hydrogel containing Kaz-6 showed enhanced germination rates, greater biomass accumulation, and significantly improved drought tolerance—surviving up to 10 days longer than controls under water-limited conditions. These findings highlight the potential of biopolymer-based hydrogels as eco-friendly seed coating materials that can improve crop resilience and productivity in arid environments. The proposed formulation aligns with sustainable agriculture goals and represents a promising direction for future field-scale applications in climate-adaptive farming systems. Full article
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15 pages, 2185 KiB  
Article
A New Ribo-Type of Wangodinium sinense from Germination of Resting Cysts Isolated from Ballast Tank Sediments of Incoming Ships to China
by Zhe Tao, Caixia Yue, Yuyang Liu, Shuo Shi, Ruoxi Li, Zhaoyang Chai, Yunyan Deng, Lixia Shang, Zhangxi Hu, Haifeng Gu, Fengting Li and Yingzhong Tang
J. Mar. Sci. Eng. 2025, 13(5), 942; https://doi.org/10.3390/jmse13050942 - 12 May 2025
Viewed by 323
Abstract
In recent decades, ships’ ballast water and associated sediments have been recognized globally as significant vectors for the dissemination of non-indigenous species, which has attracted extensive attention due to its ecological and economic impacts. The characteristics of production of resting cysts in the [...] Read more.
In recent decades, ships’ ballast water and associated sediments have been recognized globally as significant vectors for the dissemination of non-indigenous species, which has attracted extensive attention due to its ecological and economic impacts. The characteristics of production of resting cysts in the dinoflagellate life cycle further increases the risk of biological invasions through ballast tank sediments. Despite extensive research which has characterized the species diversity of dinoflagellate cysts within ballast tank sediments, the possibility and importance of invasions caused by different ribosomal types of the same species have been paid little attention. In this study, two cultures of dinoflagellates were established through cyst germination from the ballast tank sediments collected from two ships (“THETIS” and “WARIYANAREE”) arriving at the Jiangyin Port (China) and identified as Wangodinium sinense Z. Luo, Zhangxi Hu, Yingzhong Tang and H.F. Gu by comprehensive phylogenetic analysis of rDNA sequences (including LSU, SSU, and ITS1-5.8S-ITS2). Despite the rDNA sequences of the isolates showing a generally high similarity to reference sequences, the LSU D1-D6 sequences contained up to 11 stable single nucleotide polymorphisms (SNPs), while SSU and ITS1-5.8S-ITS2 sequences exhibited up to five and two divergence sites, respectively. Moreover, phylogenetic analyses based on partial LSU and SSU rDNA sequences further indicated that strains germinated from ships’ ballast tank sediments formed a strongly supported sister clade to the strains previously isolated from Chinese and Korean waters, representing a novel ribo-type distinct from Chinese and Korean strains. Detailed morphological observations using light microscopy (LM) and scanning electron microscopy (SEM) did not find differences between our isolates and the holotype of the species in key diagnostic characteristics including the position and shape of the nucleus and chloroplasts, as well as the ASC structure, which suggested that no significant morphological divergence has occurred among these ribo-types. Acute toxicity exposure assays indicated that this ribo-type of W. sinense posed no lethal effect on rotifers at concentrations ≤ 104 cells/mL, yet it remains necessary to maintain vigilance regarding the potential risk of algal blooms resulting from higher cell density or environmental changes in the invaded ecosystems. This study reports the first successful germination of W. sinense cysts from ballast tank sediments, indicating that its cysts may be widely transferred through ballast tank sediments, and presents a potential risk of bio-invasions of new genotypes of species to a region where other genotypes of the same species have been present as indigenous species. Full article
(This article belongs to the Section Marine Ecology)
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20 pages, 6526 KiB  
Article
The LBD Transcription Factor ZmLBD33 Confers Drought Tolerance in Transgenic Arabidopsis
by Jing Xiong, Xin Mi, Lijuan Du and Xianqiu Wang
Plants 2025, 14(9), 1305; https://doi.org/10.3390/plants14091305 - 25 Apr 2025
Viewed by 489
Abstract
Drought stress severely impacts maize productivity, necessitating the exploration of molecular mechanisms underlying drought responses. In maize, while Class I members of the LBD family have been extensively studied for their essential functions in developmental regulation and environmental stress responses, the potential involvement [...] Read more.
Drought stress severely impacts maize productivity, necessitating the exploration of molecular mechanisms underlying drought responses. In maize, while Class I members of the LBD family have been extensively studied for their essential functions in developmental regulation and environmental stress responses, the potential involvement of Class II LBD genes in abiotic stress tolerance mechanisms remains poorly characterized. This study characterizes ZmLBD33, a maize Class II LBD gene, to elucidate its role in drought responses. Promoter analysis identified ABA-responsive cis-elements (AREB); ZmLBD33 expression was strongly induced in roots under drought and ABA treatments, localized to the nucleus, and exhibited dimerization via yeast two-hybrid despite lacking intact leucine zipper motifs. ZmLBD33-overexpressed plants showed later germination, shorter roots, and decreased survival rates than wild-type plants under osmotic stress and soil drought. Compared to wild-type plants, ZmLBD33-overexpressed plants showed significantly faster water loss, a greater stomatal density, and reduced stomatal closure efficiency. Histochemical analysis using DAB and NBT showed attenuated reactive oxygen species accumulation in transgenic Arabidopsis overexpressing ZmLBD33. Quantitative enzymatic activity analyses further indicated that SOD and POD levels were significantly elevated in ZmLBD33-overexpressing plants compared to wild-type plants. These findings indicate that ZmLBD33 negatively regulates drought tolerance by modulating stomatal aperture and H2O2 signaling. This study highlights the divergent roles of Class II LBD genes in stress adaptation and positions ZmLBD33 as a potential target for engineering drought-resilient crops. Full article
(This article belongs to the Special Issue Plant Stress Physiology and Molecular Biology—2nd Edition)
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20 pages, 4531 KiB  
Article
Successional Allelopathic Interactions of Amaranthus palmeri S. Wats. and Cereals
by Filiz Erbas
Sustainability 2025, 17(9), 3871; https://doi.org/10.3390/su17093871 - 25 Apr 2025
Viewed by 327
Abstract
Plant allelochemicals can affect the germination and growth of other plant species. Petri and pot experiments were conducted to detect the interaction of Amaranthus palmeri with cereals (barley, oat, wheat, and triticale). Aqueous extracts of different tissues of A. palmeri and cereals at [...] Read more.
Plant allelochemicals can affect the germination and growth of other plant species. Petri and pot experiments were conducted to detect the interaction of Amaranthus palmeri with cereals (barley, oat, wheat, and triticale). Aqueous extracts of different tissues of A. palmeri and cereals at several concentrations were used to measure the inhibitory effects on the germination of other plants in the Petri experiments. A. palmeri plants and cereals grown at two different densities were incorporated into a potting mix at two different growing stages to determine the inhibitory effects on the germination and growth of other plants in pot experiments. The relative germination inhibition of A. palmeri was present in the following order: barley > oat > triticale > wheat. The relative germination inhibition of cereals was present in the following order: oat > triticale > barley > wheat. The above-ground parts of the plants were more effective than the roots. The germination of A. palmeri was only affected by wheat, while barley was better at reducing the dry weight in pot experiments. Wheat was found to be the only cereal affected by A. palmeri. Despite the prevailing hypothesis that these plants do not affect each other’s germination and development in nature, it was concluded that using wheat and barley as a cover crop can support A. palmeri management, and delaying wheat planting in the presence of A. palmeri can protect cereals from allelopathic interference. Full article
(This article belongs to the Section Sustainable Agriculture)
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14 pages, 3467 KiB  
Article
Optimizing Soybean Productivity: A Comparative Analysis of Tillage and Sowing Methods and Their Effects on Yield and Quality
by Agnieszka Faligowska, Katarzyna Panasiewicz, Grażyna Szymańska and Karolina Ratajczak
Agriculture 2025, 15(6), 626; https://doi.org/10.3390/agriculture15060626 - 15 Mar 2025
Viewed by 1135
Abstract
This study underscores the critical role of tillage methods in optimizing soybean yield and quality. Plowed tillage + strip-drill sowing (PSD) offers a balance between crop productivity and quality by maintaining soil structure while enhancing nutrient availability. Reduced tillage methods such as zero [...] Read more.
This study underscores the critical role of tillage methods in optimizing soybean yield and quality. Plowed tillage + strip-drill sowing (PSD) offers a balance between crop productivity and quality by maintaining soil structure while enhancing nutrient availability. Reduced tillage methods such as zero tillage + strip-drill (ZSD) and no-plowed tillage + strip-drill (NSD) can improve leaf greenness by about 10–15% and pod numbers by 6.7% and 3.5%, respectively. However, such methods may reduce seed quality and germination capacity, impacting the overall yield. In contrast, plowed tillage + conventional row sowing (PCR) promotes balanced nutrient composition and carbohydrate production under optimal soil conditions. Tillage practices significantly influence nutrient components such as ash content, which ranges from 55.8 g kg−1,(PCR) to 57.4 g kg−1 (ZSD). ZSD was found to enhance protein levels by 3% at the expense of carbohydrates, likely due to improved nutrient retention. The present analysis highlights ZSD as an effective method for stabilizing protein yield (mean value 843.8 kg ha−1) and fat yield (mean value 449.3 kg ha−1) across variable environments, supporting the use of ZSD in conservation agriculture. Future studies should explore how tillage practices affect soil health, economic sustainability, and yield stability over time, especially under changing climatic conditions. Optimizing plant density, enhancing seed traits, and improving germination can collectively drive significant improvements in soybean productivity across diverse agro-ecological zones. Full article
(This article belongs to the Special Issue Sustainable Management of Legume Crops)
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20 pages, 1887 KiB  
Article
Alkaline Extraction in Air Enhances Antioxidant and Biological Activities of Humic Acids
by Anna Zavarzina, Irina Davydova, Natalia Kulikova, Anastasiya Nikolaeva and Olga Philippova
Agronomy 2025, 15(3), 689; https://doi.org/10.3390/agronomy15030689 - 13 Mar 2025
Viewed by 674
Abstract
Humic acids (HAs) possess diverse functionalities, endowing them with multiple applications as bioactive compounds in agriculture. Alkaline extraction is key to obtaining HAs from their source material. The presence of oxygen during extraction can lead to oxidative changes in the humic structure. The [...] Read more.
Humic acids (HAs) possess diverse functionalities, endowing them with multiple applications as bioactive compounds in agriculture. Alkaline extraction is key to obtaining HAs from their source material. The presence of oxygen during extraction can lead to oxidative changes in the humic structure. The extent of HA transformation depending on their origin remains poorly understood, and the effect of alkaline extraction on the HA biological activities is yet to be estimated. Here, we compare the physicochemical properties of HAs extracted from fresh organic material, compost, in air (HA-O2) and under nitrogen (HA-N2). We also assess the antioxidant properties of HAs-O2 and HAs-N2 from compost (HAC), Retisol (HAR), and Chernozem (HACh) and relate them to the HA biological activities. Changes in the HAC properties were analyzed using the following techniques: elemental composition, ultraviolet–visible and infrared spectroscopy, 13C nuclear magnetic resonance (13C-NMR), electron paramagnetic resonance (EPR), gel filtration using Sephadex G-75 gel, and potentiometric titration. The HA antioxidant properties were explored using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay (antiradical activity) and phosphomolybdenum assay (total antioxidant capacity). The HA biological activity was estimated by priming radish and wheat seeds (0.5 g L−1 HAs, 25 °C, 5 h for radish and 14 h for wheat), followed by germination tests. Alkaline extraction of HAC in air vs. nitrogen resulted in a 1.2-fold increase in the O/C ratio and optical density at E465, oxidation of aliphatic fragments, a 2-fold increase in the contents of functional groups, and a 1.2-fold increase in the number of paramagnetic centers. All HA-O2 preparations have demonstrated an enhanced antiradical activity (1.3–1.6 times) and total antioxidant capacity (1.1–1.3 times) compared to HA-N2. The Vigor Index of seeds primed with HA-O2 was 1.1-to-1.8-fold higher than those treated with HA-N2, depending on the HA origin. We demonstrate that alkaline treatment in air benefits the antiradical and biological activities of HAs, making such preparations more attractive for use as natural antioxidants and priming agents. This opens up new perspectives for using O2-modified HAs as innovative plant stimulants in agriculture. Full article
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52 pages, 17724 KiB  
Article
Thermal Influence of Volcanic Tephra on Maximum Soil Temperatures: Geoecological Implications for Germination and Distribution of Argyroxiphium sandwicense (Haleakalā, Maui, Hawai’i)
by Francisco Luis Pérez
Geographies 2025, 5(1), 13; https://doi.org/10.3390/geographies5010013 - 11 Mar 2025
Viewed by 2289
Abstract
Mid-day maximum soil temperatures were measured at 10 study plots during different hot summer days in Haleakalā Crater, Maui, with thermocouple thermometers on five adjacent microsite types: bare surface soils, soils under black tephra, soils under reddish tephra, soils shaded by silverswords, and [...] Read more.
Mid-day maximum soil temperatures were measured at 10 study plots during different hot summer days in Haleakalā Crater, Maui, with thermocouple thermometers on five adjacent microsite types: bare surface soils, soils under black tephra, soils under reddish tephra, soils shaded by silverswords, and soils under plant litter. The main tephra morphologies and geomorphic environments, as well as their geoecological association with silversword rosettes (Argyroxiphium sandwicense), were also assessed; silversword density was substantially greater on reddish tephra-covered areas than under black tephra fragments. Silversword seeds are extremely sensitive to high temperatures and fail to germinate after a short exposure to soil temperatures ≥35 °C. Thermal data sets were statistically compared with parallel box plots; the ability of various microsites to provide safe sites for silversword growth was also assessed. Bare soils and black tephra reached the highest median temperatures, up to 48.7 °C and 40.3 °C, respectively; reddish tephra remained much cooler, with all median temperatures ≤30.8 °C. Rosette-shaded soils and soils under silversword litter were the coolest, with temperatures below 18.7 °C and 18.5 °C, respectively. Temperatures in all microsites, except those under black tephra, were significantly lower (p < 0.0001) than on contiguous bare ground. It was concluded that reddish tephra provides the ideal conditions for silversword regeneration. Full article
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16 pages, 5731 KiB  
Article
Calibration and Analysis of Seeding Parameters of Soaked Cyperus esculentus L. Seeds
by Jianguo Yan, Zhenyu Liu and Fei Liu
Appl. Sci. 2025, 15(6), 2951; https://doi.org/10.3390/app15062951 - 9 Mar 2025
Cited by 1 | Viewed by 724
Abstract
The seeds of Cyperus esculentus L. exhibit an uneven surface and irregular shape, which adversely affect precision seeding. Pre-sowing seed soaking treatment not only improves seeding performance, but also enhances the germination capability of C. esculentus seeds. However, the intrinsic parameters of the [...] Read more.
The seeds of Cyperus esculentus L. exhibit an uneven surface and irregular shape, which adversely affect precision seeding. Pre-sowing seed soaking treatment not only improves seeding performance, but also enhances the germination capability of C. esculentus seeds. However, the intrinsic parameters of the seeds undergo significant changes after soaking in terms of their physical properties, such as volume, weight, and density. These changes directly influence the fluidity and positioning accuracy of the seeds during the seeding process. Additionally, contact parameters, such as the coefficient of friction and the contact area between the seeds and the seeding apparatus, are altered by soaking. These parameters are crucial for designing efficient seeding devices. Therefore, it is necessary to measure the intrinsic parameters of soaked C. esculentus seeds and their contact parameters with the seeding apparatus to provide parameter support for the precision seeding analysis of pre-soaked C. esculentus. This study focuses on the calibration and experimental investigation of discrete element parameters for soaked C. esculentus seeds. Free-fall collision tests, static friction tests, and rolling friction tests were conducted to calibrate the contact parameters between soaked C. esculentus seeds and between the seeds and steel materials. Using Design-Expert, Plackett–Burman tests, steepest ascent tests, and Box–Behnken response surface tests were designed to obtain the optimal parameter combination for the C. esculentus contact model. The optimal parameters were validated through angle of repose simulation tests and physical experiments. The results indicate that the rolling friction coefficient (F) between seeds, the static friction coefficient (E) between seeds, and the rolling friction coefficient (J) between seeds and steel plates significantly affect the angle of repose. The optimal combination of discrete element parameters is as follows: the static friction coefficient (E) between seeds is 0.675, the rolling friction coefficient (F) between seeds is 0.421, and the rolling friction coefficient (J) between seeds and steel plates is 0.506. Using the calibrated parameters for simulation, the average angle of repose was 32.31°, with a relative error of 1.1% compared to the physical experiments. Full article
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17 pages, 2673 KiB  
Article
Morphological and Phytochemical Characterization of Old Ligurian Basil Accessions: Recovery of Old Biodiversity for Future Exploitation
by Federica Betuzzi, Denise Campioli, Paola Malaspina, Fabio Rapallo, Giovanni Bottino, Gloria Scrigna, Giovanni Minuto and Laura Cornara
Plants 2025, 14(4), 553; https://doi.org/10.3390/plants14040553 - 11 Feb 2025
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Abstract
Since the 19th century, the cultivation of Ocimum basilicum L. has increasingly been established in Liguria, with the in situ reproduction of seeds. Over the years, Ligurian basil accessions were crossed with allochthonous genomes to obtain disease-resistant plants. To preserve the original genetic [...] Read more.
Since the 19th century, the cultivation of Ocimum basilicum L. has increasingly been established in Liguria, with the in situ reproduction of seeds. Over the years, Ligurian basil accessions were crossed with allochthonous genomes to obtain disease-resistant plants. To preserve the original genetic resource, nine old Ligurian accessions (CV1–9) were recovered. As part of the PSR 2014–2022 Mis. 10.2 of Liguria Region, this work aimed to characterize these CVs by morphological and phytochemical analyses to safeguard their biodiversity. Commercial O. basilicum Genovese Superbo grown in Liguria (SL) was added for comparison. The micro-morphological investigation showed significantly different trichome densities among the samples. CV4 showed the highest densities of both peltate and capitate trichomes, while CV9 and CV1 had the lowest peltate and capitate densities, respectively. In addition, to perform the germplasm characterization, seed morphometric data and germinability were evaluated. Volatile Organic Compounds (VOCs) analysis was carried out on CV1–9, SL, and Superbo plants grown in Piedmont (SP), to test the influence of territory on basil aromatic profiles. The results showed that the old accessions and SL were rich in linalool, eugenol, and bergamotene. Only CV1 slightly differed, with higher levels of methyl eugenol, eucalyptol, and camphor. On the contrary, SP had very high levels of methyl eugenol and camphor. These data represent valuable insights for preserving Ligurian old basil accessions and maintaining the production of Genovese Basil PDO (Protected Designation of Origin) in the future. Full article
(This article belongs to the Collection Bioactive Compounds in Plants)
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