Search Results (80)

Cashew (Anacardium occidentale L.), a vital tropical cash crop, may face yield declines in old plantations due to unexplored risks of autotoxicity. This study investigated the allelopathic and autotoxic potential of cashew plant under laboratory and greenhouse conditions. The laboratory bioassays with leaf and stem bark (10–200 mg) demonstrated a strong allelopathic effect, reducing lettuce radicle elongation to 7–46.0% and 9–79% of the control, respectively. Aqueous leaf extract (50 mg/mL) completely inhibited (0%) lettuce seed germination and reduced pepper germination to 42%. However, the root exudate of cashew seedlings did not have any inhibitory effect on the test plants. Greenhouse experiments simulating field litter fall revealed significant autotoxicity in cashew. Cashew seedlings grown in growth media amended with 10% cashew leaf powder exhibited severe growth suppression after 13 weeks, including a reduction in plant height by 58.2% compared to controls. Chlorophyll content, stem girth, and leaf number were also significantly reduced. This study concludes that cashew possesses significant allelopathic properties and a clear potential for autotoxicity, as directly evidenced by the suppressed growth of its own seedlings following the incorporation of leaf powder. These findings identify autotoxicity, mediated through leaf litter decomposition, as a critical risk factor for the replanting success and long-term sustainability of cashew orchards, necessitating further investigation into management strategies. Full article

Inefficient fertilization practices frequently take place in orchards in Dangshan County, leading to substantial changes in soil properties and pear tree growth. To comprehensively evaluate the long-term impact and identify limiting factors, this study assessed the effects of 30-year fertilization across different soil layers in “Dangshansuli” pear orchards. In May 2020, 30 soil samples were collected from a long-term fertilized plot and an unfertilized sandy control. The analyses focused on the physicochemical properties, mineral elements, heavy metals, chemical compound diversity, and allelopathic effects. The results showed that long-term fertilization significantly reduced soil pH (e.g., from 8.1 to 7.3 in the topsoil) and increased the content of soil organic matter by about 3.7-fold in the 0–20 cm layer. The contents of available potassium, exchangeable calcium, and magnesium in fertilized soil were optimal for pear growth, whereas available iron was deficient. Although fertilization led to the accumulation of heavy metals (Cu, Hg, Ni, Cr, As, Mn), their concentrations remained within national safety limits. The number of chemical compounds detected in fertilized soil was over 40% higher than in the control. Allelopathy tests indicated that 0.18 mmol·L⁻¹ of octadecane strongly inhibited the root growth of “Shanli” (Pyrus ussuriensis Maxim.) tissue-cultured seedlings by more than 50%. These findings provide a scientific basis for optimizing fertilization strategies in “Dangshansuli” pear orchards. Full article

Heracleum sosnowskyi is considered to be a dangerous invasive plant species that has successfully naturalized within a variety of plant communities across numerous countries. As a result of its superior competitiveness, the alien species is able to displace the indigenous species from their native habitats, thus changing the ecosystems and decreasing biodiversity. The phytochemicals present in the H. sosnowskyi aqueous extracts were revealed using GC/MS and HPLC/DAD/TOF techniques. Isopsoralen, methoxsalen, (iso)pimpinellin and/or bergapten were determined to be major compounds in the leaf, inflorescence and root extracts. Glutaric, quinic, linolenic, (iso)chlorogenic and other polyphenolic acids were identified in the extracts. Furthermore, a number of furanocoumarins, including hermandiol, bakuchicin, candinols (A and C) and candibirin F, and coumarins, umbelliferone and yunngnins (A and B), were identified in the roots. Additionally, the presence of flavonoids, including astragalin, quercetin 7,3,4-trimethyl ether, nicotiflorin and rutin, has been detected in the flower and leaf extracts. Allelopathic effects of H. sosnowskyi aqueous extracts were tested on four model plants, lettuce (Lactuca sativa L.) and three native Lithuanian meadow herbs, perennial ryegrass (Lolium perenne L.), timothy (Phleum pratense L.) and white clover (Trifolium repens L.), using the Petri dish method. H. sosnowskyi flower and leaf extracts demonstrated the strongest inhibitory effects on the germination and growth of the tested plant seeds. At the highest relative concentrations, 0.5 and 1.0, extracts of Sosnowsky’s hogweed inflorescences inhibited timothy seedling growth by 95.47% (from 19.64 ± 2.57 mm to 0.89 ± 0.73 mm) and 100%, respectively. The leaf extracts exhibited the strongest inhibitory effects on white clover seedlings. The highest relative concentrations tested (0.5 and 1.0) suppressed clover seedling growth by 94.66% (from 41.22 ± 2.53 mm to 2.20 ± 0.63 mm) and 100%, respectively. Additionally, the germination rate and vigor index of model plants were assessed. The research is of significance for the regulation and monitoring of the spreading of aggressive H. sosnowskyi plants. Moreover, it is important for the development of natural herbicides based on active phytotoxic compounds from these plants. Full article

Heracleum sosnowskyi Manden., or H. sosnowskyi, of the Apiaceae was first cultivated in the USSR in 1947 as a potential fodder plant. Due to the development of cold-resistant cultivars and the characteristics of H. sosnowskyi, it quickly became feral. As a result, H. sosnowskyi began to spread as an aggressive invasive species in the 1970s and 1980s. By the 90s it had become an ecological disaster. As well as forming monocultures and displacing native species, H. sosnowskyi contains furanocoumarins, photosensitizing compounds that increase skin sensitivity to ultraviolet rays and cause severe burns. In addition, furanocoumarins have cytotoxic, genotoxic, mutagenic and estrogenic effects. H. sosnowskyi also contains essential oils, which are particularly active during flowering and can irritate the mucous membranes of the eyes and respiratory tract, as well as cause allergic reactions in the form of bronchospasm in people with asthma and hypersensitivity. When released in high concentrations, these biologically active compounds have an allelopathic effect on native plant species, displacing them and reducing biodiversity. As H. sosnowskyi is not native; the biologically active compounds it secretes have a xenobiotic effect, causing serious damage to the ecosystems it occupies. However, in parallel with these negative properties, furanocoumarins have been found to be effective in the treatment of cancer and skin diseases. Furanocoumarins possess antimicrobial antioxidant osteo- and neuroprotective properties. Essential oils containing octyl acetate, carboxylic acid esters, and terpenes can be used in the pharmaceutical industry as antiseptic and anti-inflammatory agents. Additionally, essential oils can be used as biofumigants and natural herbicides. A comprehensive approach allows H. sosnowskyi to be viewed in two ways. On the one hand, it is an aggressive alien species that causes significant damage to ecosystems and poses a threat to human health. On the other hand, it is a potentially valuable natural resource whose biomass can be used within the principles of the circular economy. It is hoped that the use of H. sosnowskyi for economic interests can be a partial compensation for the problem of its aggressive invasion, which is of anthropogenic origin. Full article

Crateva tapia L. is a native tree species of the Caatinga biome, with medicinal and allelopathic properties. This study aimed to characterize the biometric and morphological traits of fruits, seeds, seedlings, and young plants of C. tapia, as well as to evaluate the germination pattern of its seeds under different temperatures, in order to understand the reproductive strategies and optimal conditions for its propagation. The results are intended to support conservation efforts, ecological restoration, and the sustainable use of the species within the Caatinga biome. The research was carried out at the Seed Analysis Laboratory of the Federal University of Paraíba, Campus II, Areia–PB, Brazil. The biometric data were obtained from 100 fruits and 100 seeds obtained from eight mother plants. The imbibition curve was determined from the weight of the seeds during 216 h at different temperatures, and the germination test was performed concomitantly. The fruits were morphologically described regarding the external and internal aspects of the pericarp. The seeds were described according to their consistency, color, texture, shape, hilum, and embryo. The fruits of C. tapia vary in size, fresh mass, and number of seeds, characterized as amphisarcidium, indehiscent, and polyspermic. The seeds are small, brown, reniform, and biting, with a cotyledonary embryo with a poorly differentiated hypocotyl–radicle axis, with a well-developed hilum and surrounded by a fleshy mesocarp. The germination of C. tapia seeds is epigeal-phanerocotyledonous; the seedlings have white axial roots containing absorbent hairs. Full article

Today’s primary challenges include identifying efficient, affordable, and environmentally sustainable substances to serve as raw materials in industrial, agricultural, and medicinal applications. This study aimed to evaluate the chemical composition and biological properties (namely antioxidant and allelopathic activities) of the methanolic extract derived from the above-ground portions of Artemisia judaica collected in Jazan, Saudi Arabia. GC-MS was used to evaluate the chemical composition of the methanolic extract derived from Artemisia judaica. GC-MS analysis revealed a total of 22 volatile compounds in the extract. The most prominent compounds identified were 2-ethylhexanoic acid, 5-hydroxy-6-(1-hydroxyethyl)-2,7-dimethoxynaphtho-quinone, and piperitone. The extract demonstrated strong antioxidant activity in both the DPPH and ABTS radical scavenging assays, comparable to the standard antioxidant ascorbic acid. The IC₅₀ value for the extract was 31.82 mg/mL in the DPPH assay and 39.93 mg/mL in the ABTS testing. Additionally, the extract exhibited dose-dependent inhibition of seed germination, root growth, and shoot growth of the weed Chenopodium murale in allelopathic bioassays. The most significant suppression was observed in shoot growth with an IC₅₀ value of 45.90 mg/mL, which was lower than the IC₅₀ values for root development and seed germination of C. murale, recorded at 56.16 mg/mL and 88.80 mg/mL, respectively. Furthermore, the findings indicated that methanolic extracts had significant lethal toxic effects on the life cycle of Aedes aegypti. Future research will focus on extracting uncontaminated substances and evaluating the biological effects of each specific constituent. Full article

To date, various species of Erigeron genus have been used both in the ethnopharmacology of numerous nations across the world and in contemporary herbal practices. The objective of this study is to revise the phytochemical data on the essential oils (EOs) of various fleabanes species and to evaluate the variability of their biological activities. Up to June 2025, this review provides an updated overview of 105 literature sources (published during last 25 years) related to 14 Erigeron sp. (native, naturalized, or invasive) which have been investigated extensively and are of the greatest significance. It summarizes the compositional variability of the EOs and their pharmacological and toxic effects, such as anti-inflammatory, anticancer, antiproliferative, skin regeneration, antioxidant, antifungal, antibacterial, insecticidal, larvicidal, repellent, and allelopathic activity. The EOs of each Erigeron species were characterized, and a chemical structure of 43 major constituents is presented herein. The most characteristic and prevalent compounds were found to be limonene, δ-3-carene, matricaria ester, lachnophyllum ester, germacrene D, β-caryophyllene, β-farnesene, α-bergamotene, allo-aromadendrene, etc., in the EOs from the E. acris, E. annuus, E. bonariensis, E. canadensis, E. floribundus E. mucronatus, and E. speciosus plants. Major constituents, such as borneol, bornyl acetate, modhephen-8-β-ol, cis-arteannuic alcohol, β-caryophyllene, and τ-cadinol, were found in the oils of E. graveolens (Inula graveolens). A paucity of data concerning E. incanus EOs was revealed, with the prevalence of 3-hydroxy-4-methoxy cinammic acid and thymol acetate noted in the oils. The EOs from E. multiradiatus and E. sublyratus were comprised mainly of matricaria and lachnophyllum esters. The available data on EOs of E. ramosus is limited, but the main constituents are known to be α-humulene, 1,8-cineole, eugenol, and globulol. The EOs containing appreciable amounts of matricaria and lachnophyllum esters exhibited strong anticancer, anti-inflammatory, antimicrobial, larvicidal, and repellent activities. Repellence is also related to borneol, bornyl acetate, caryophyllene derivatives, τ-cadinol, modhephen-8-β-ol, and cis-arteannuic alcohol. Cytotoxicity was determined due to the presence of limonene, δ-3-carene, α- and β-farnesene, (E)-β-ocimene, ledene oxide, sesquiphellandrene, and dendrolasin in the fleabanes EOs. Skin regeneration and antifungal properties were related to germacrene D; and anti-inflammatory effects were determined due to high amounts of limonene (E)-β-ocimene, lachnophyllum ester, and germacrene D. The antimicrobial properties of the oils were conditioned by appreciable quantities of limonene, β-pinene, 1,8-cineole, carvacrol, thymol acetae, β-eudesmol, 2,6,7,7α-tetrahydro-1,5-dimethyl-1H-indene-3-carboxaldehyde, caryophyllene and its oxide, allo-aromadendrene, α-humulene, farnesene, carvacrol, and eugenol. This review provides a foundation for further studies on volatile secondary metabolites to explore the potential sources of new biologically active compounds in Erigeron sp. Full article

The bio-prospecting of bioactive phytochemicals from invasive flora presents a sustainable paradigm for the ecologically conscious management of major invasive pest S. invicta. Ageratina adenophora, while recognized for its allelopathic insecticidal properties, exhibits poorly characterized toxicological profiles and mechanistic underpinnings against S. invicta, warranting systematic investigation to elucidate its mode of action. This study elucidates the bioactive insecticidal compounds of A. adenophora and their toxicological impacts on S. invicta, including behavioral, metabolic, and enzymatic perturbations, via liquid chromatography–mass spectrometry (LC-MS) profiling. The ethanol extracts of the roots, stems, and leaves of A. adenophora have shown control effects on S. invicta, with an LC₅₀ (50% lethal concentration) of 331.847, 188.256, and 166.253 mg/mL at 48 h, respectively. Metabolite profiling of A. adenophora revealed that safranal and dihydrocoumarin are relatively high in plant leaves, and they showed significant insecticidal activity and behavioral inhibitory effects on S. invicta with LC₅₀ 349.042 mg/L and 118.336 mg/L at 48 h, respectively. Notably, these two bioactive compounds disrupted the normal energy production through glucose metabolism and the citrate cycle, which eventually led to the death of S. invicta. Further, these two compounds also activated the detoxification metabolic pathway of S. invicta. These findings provide a theoretical basis for the use of these bioactive compounds in the integrated management of S. invicta and may lead to the development of a new biopesticide. Full article

Allelopathy plays a major role in agricultural production, influencing plant protection, crop yield, and crop rotation systems. This study investigated the effects of root exudates on 3105c alfalfa (Medicago sativa) seeds and seedlings to identify crops with strong and weak allelopathic potential. The results revealed that corn (Zea mays L.) (T1) exhibited the strongest allelopathic effects, whereas soybean (Glycine max (Linn.) Merr.) (T10) exhibited the weakest effects. T1 promoted seed germination by increasing radicle length and the simple vitality index. Both T1 and T10 promoted 3105c seedling growth and enhanced antioxidant capacity, albeit through different mechanisms. T1 primarily increased antioxidant capacity by elevating ascorbate and dehydroascorbate levels while reducing malondialdehyde content. In contrast, T10 enhanced antioxidant capacity by increasing soluble sugar and protein levels via hydroxyl free radical inhibition. These findings demonstrate that the allelopathic properties of corn effectively promote alfalfa growth by enhancing seed germination and improving physiological stress resistance. Full article

The mixotrophic dinoflagellate Akashiwo sanguinea is known to have acute toxic effects on multiple marine organisms, while the composition and chemical properties of its toxins remain unclear. In this study, we established a method for separation and purification of A. sanguinea toxins using chromatographic techniques. The acetone extract of A. sanguinea exhibited higher hemolytic activity and shorter incubation time compared to methanol and ethyl acetate extracts. Five fractions were obtained by solid-phase extraction (SPE), of which SPE3 (acetone/water ratio 3:2) and SPE4 (acetone/water ratio 4:1) exhibited the highest hemolytic activities and allelopathic effects. Further purification on SPE3 and SPE4 using reverse-phase high-performance liquid chromatography (RP-HPLC) coupled with a diode array detector (DAD) resulted in 11 subfractions, among which Fr4-5 displayed the strongest hemolytic activity. Nearly all active subfractions exhibited higher hemolytic activities incubated under light than those in the dark (p < 0.05), suggesting that A. sanguinea can produce both photosensitive and non-photosensitive toxins, with the former being the primary contributors to its hemolytic activity. Molecular characterization by UV-Vis, FTIR, and HRMS/MS analysis revealed that the structural features of Fr4-5 were highly consistent with porphyrin analogs and could be derived from chlorophyll c-related precursors. These findings highlight that the photosensitive toxins in A. sanguinea may serve dual roles in stress adaptation and ecological competition, potentially contributing to the formation of the blooms. Full article

In spite of the many chemical reports on polyacetylenes of the genus Artemisia, combined conclusions regarding their distribution and biological functions are widely missing. The aim of the present review was to arrange the diversity of polyacetylenes in the genus following biogenetic aspects and group them together into characteristic structural types. The co-occurrence of the dehydrofalcarinol type with the aromatic capillen-isocoumarin type represents a characteristic biogenetic trend, clearly segregating species of the subgenus Dracunculus from those of the subgenera Artemisia and Absinthium, distinguished by the spiroketal enol ether and/or linear triyne type. Various accumulation trends toward specific structures additionally contribute to a more natural species grouping within the subgenera. Biological activities were reported for all four structural types, ranging from antifungal, insecticidal, nematicidal, and cytotoxic properties to allelopathic effects. Of particular interest were their remarkable cytotoxic potencies, from which the very high values of dehydrofalcarin-3,8-diol may be associated with the pronounced affinity of this type to form extremely stable bonds to proteins acting in signaling pathways. The aromatic acetylene capillin inhibited the viability of various tumor cells in a dose- and time-dependent manner. Its potent apoptosis-inducing activity was induced via the mitochondrial pathway. A group of spiroketal enol ethers was identified as inhibitors of PMA-induced superoxide generation. Among them, the epoxide of the isovalerate ester exhibited the highest potency. The ecological impact of acetylene formation was made apparent by the allelopathic effects of DME of the linear triyne type, and the aromatic capillen by inhibiting seed germination and growth of widespread weeds. Full article

Justicia adhatoda, also known as Adulsa or Vasaka, is a notable member of the family Acanthaceae, with a broad geographic distribution across varied climatic conditions, and is known for its extensive medicinal properties for treating respiratory disorders, tuberculosis, malaria, and dysentery. It possesses several pharmacological activities, including anti-bacterial, anti-fungal, and anti-cancerous ones. In addition to discussing its morphology, phytochemistry, and pharmacological aspects, the present review also focuses on its several unexplored facets, such as pollination mechanism, cytology, molecular and genetic aspects, conservation, and ecological attributes. The literature survey indicates that, despite its medicinal value, J. adhatoda is also a strong invader in various ecosystems, suppressing associated species and cause vegetation homogenization. It also provides several ecosystem services, including soil stabilization, ecological restoration, and phytoremediation by removing contaminants such as chromium and mercury from wastewater. Additionally, its leaves increase the nitrogen content in compost, promote the proliferation of earthworms, and help suppress plant diseases. This highlights its potential for sustainable land management and integrated disease control. The urgency of this research is underscored by the significant gap in the literature regarding the ecological interactions of J. adhatoda, particularly its allelopathic effects on other plant species. The findings underscore the need for sustainable utilization and conservation strategies, emphasizing the dual importance of J. adhatoda as a medicinal resource and an ecological disruptor. Full article

Globalization has greatly expanded the opportunities for plant species to enter new areas through a wide range of pathways. Elucidating the pathways of spread of alien species and the characteristics of organisms that make them invasive is one of the most pressing problems in ecological sciences. Once established, alien species may have serious implications for communities and vice versa. Allelopathy has been proposed as one of the possible invasion mechanisms of exotic plants. Impatiens parviflora and Impatiens glandulifera are among the widely spread invasive plant species in the Baltic region. The aim of the study was to evaluate the allelopathic effect of invasive Lithuanian Impatiens spp. and their neighboring plants (11 pristine species) using parameters of germination and seedling growth of biotest species Lepidium sativum, and to expand this study by determining the content of phenolic compounds and the radical scavenging activity in the leaf extracts of Lithuanian Impatiens spp. populations (20 of each Impatiens species). Leaf extracts of all species examined had an inhibitory effect on Lepidium sativum germination and morphology of the seedlings. In our study, at all leaf extract concentrations, significantly higher allelopathic potential on radicle growth was characteristic of I. glandulifera compared to native species Alnus glutinosa, Calystegia sepium, and Urtica dioica. At all leaf extract concentrations, I. parviflora showed significantly higher allelopathic potential on radicle growth compared to native species Urtica dioica. Impatiens glandulifera had a higher juglone index than Impatiens parviflora. I. glandulifera also had the highest juglone index compared to all neighboring species studied. The differences between the populations in the content of phenolic compounds, DPPH and ABTS radical scavenging activity were 2.3, 2.2 and 2.7 times for I. glandulifera and 2.6, 5.2 and 2.7 times for I. parviflora. The mean values of total phenolic content, DPPH and ABTS radical scavenging activity of I. glandulifera populations were 2.1, 2.7 and 3.3 times higher than those of I. parviflora populations, respectively. In general, our results about allelopathic potential and phenolics content, as well as free radical scavenging ability, confirm the supreme competitive ability of I. glandulifera compared to both I. parviflora and to the native co-occurring species. Full article

Essential oils (EOs) are mixtures of volatile organic compounds that mediate plant interactions and are also appreciated for their biological properties in aromatic plants. However, the study of EOs in wild plants with biological activity has been neglected. Ipomoea murucoides is a wild species with allelopathic and insecticide activities; however, the climate factors associated with EOs and their role in intra- and interspecific interactions are still unknown. We investigated the effects of temperature, rain, and solar irradiance for two years on the EOs of I. murucoides and documented the effect of herbivory (without, <20%, >20%, and mechanical damage) on their composition. We evaluated the receptivity to possible infochemicals in conspecific and congeneric neighbors to I. murucoides plants exposed to methyl jasmonate (MeJA), herbivory by Ogdoecosta biannularis and without an elicitor. We measured the stomatal density and aperture in the second leaf generation of the neighbor plants. The year and herbivory >20% affected the composition of EOs. Nerolidol could be a biological marker for herbivory. We concluded that herbivory and rain irregularity contribute to EOs changing. The response in the stomatal density in plants not consumed by I. pauciflora but near I. murucoides under MeJA or herbivory gives evidence of interspecific plant–plant communication. Full article

Climate change and nutrient enrichment are increasing the frequency of algal blooms, with sometimes significant impacts on coastal ecosystems. Haslea ostrearia blooms have been documented in oyster ponds and are not harmful, yet their effects in open environments remain underexplored. Marennine, a blue pigment produced by H. ostrearia, can display a range of biological properties in laboratory conditions, including antibacterial and allelopathic properties. Other blue Haslea species, forming blooms, synthesize bioactive marennine-like pigments. This study aims to understand if and how these blooms could affect the underlying community of microorganisms living in the biofilms. Morphological and molecular techniques were used to assess community dynamics during bloom events. Our findings indicate that blue Haslea blooms do not significantly alter the diatom or bacterial populations. However, they are paired with enhanced alpha diversity in the microbial communities. These observations suggest a complex interaction between bloom events and microbial dynamics. Additionally, this study expands our understanding of the bioactive properties of marennine-like pigments and their ecological roles, suggesting new avenues for biotechnological applications. This work underscores the importance of further research into the environmental and biological implications of blue Haslea blooms. Full article