Allelopathic Inhibitory Effect Research Articles

Applying a neural network machine learning model to predict seasonal allelopathic inhibitory effects of Myriophyllum spicatum on the growth of Microcystis aeruginosa

Applying a neural network machine learning model to predict seasonal allelopathic inhibitory effects of Myriophyllum spicatum on the growth of Microcystis aeruginosa

Effects of 13C isotope-labeled allelochemicals on the growth of the invasive plant Alternantheraphiloxeroides

The secondary metabolites of indigenous plants have significant allelopathic inhibitory effects on the growth and development of invasive alien plants. Methyl palmitate (MP) and methyl linolenate (ML) were used as exogenous allelopathic substances. The research investigated the differences of inhibitory effects of MP and ML on the growth of seedlings of Alternantheraphiloxeroides, and calculated their morphological characteristics, biomass, physiological indicators and the response index (RI). The synthetical allelopathic index (SE) of 1 mmol/L MP was the smallest (− 0.26) and the allelopathic inhibition was the strongest; therefore, it was selected as a 13C-labeled allelochemical. The distribution of 1 mmol/L MP in different parts of A.philoxeroides and the correlation between the biomass ratios of roots, stems and leaves and the 13C content were studied by 13C stable isotope tracing experiments. Atom percent excess (APE) between roots, stems and leaves of A.philoxeroides treated with 1 mmol/L MP were significantly different in terms of magnitude, with leaves (0.17%) > roots (0.12%) > stems (0.07%). The root, stem and leaf biomass ratios of invasive weeds had great significant positive correlation with 13C content (p < 0.01, R2 between 0.96 and 0.99). This current research provides a new idea and method for the control of A.philoxeroides, but large-scale popularization remains to be studied.

Allelopathic potential of aqueous extracts of passion fruit Passiflora mucronata fruit peels on lettuce

Pesticide misuse has led to problems in agriculture, contamination of environment, and human health. However, research into alternative methods of controlling invasive plants is expanding. The allelopathic effect of secondary metabolites from plant parts suggests a potential and sustainable alternative to plant residues for use as bioherbicides. Given the above, the current study aimed to investigate the allelopathic potential of various concentrations of the aqueous extract of fruit peels of genotypes of Passiflora mucronata in seed germination and seedling growth of Lactuca sativa L. Fruit peels of genotypes of P. mucronata were used to obtain an aqueous extract, which was then filtered and diluted at the following concentrations: T1=100; T2=50; T3=25; T4=12.5 mg mL-1; T5= negative control (distilled water) and T6= positive control (glyphosate). Germination was carried out in Petri plates and was conditioned in a biochemical oxygen demand germination chamber at 25 ± 2 °C. Macroscopic evaluation was performed at the germination stage and root and aboveground growth of the seedlings, and the germination velocity index were also evaluated. Cytogenetic analysis was performed, and mitotic index was obtained. The design was entirely randomized, with five repetitions of 25 seeds each. Allelopathic substances found in the bark of P. mucronata fruits interfere with seed germination and vigor, as well as initial seedling growth. The germination of L. sativa seeds was 100% inhibited by extract concentrations of 50 % and 100 %. The cell cycle of L. sativa seeds is inhibited by allelopathic substances present in the bark of P. mucronata fruits. It is concluded that aqueous extracts of Passiflora mucronata have an allelopathic inhibitory effect on germination and initial growth of L. sativa

In vitro evaluation of the potential allelopathic and ichthyotoxic effect of the raphidophyte Heterosigma akashiwo and the dinoflagellate Alexandriumcatenella

Ichthyotoxic algal blooms cause economic losses throughout the world. However, the mechanisms and molecules proposed so far fail to explain the massiveness of these events. In this research, the allelopathic effect of two bloom-forming species (the raphidophyte Heterosigma akashiwo and dinoflagellate Alexandrium catenella) was evaluated between them and with Rhodomonas salina bioassay. Mono- and co-cultures were carried out with the aim of providing evidence of the relation between allelopathy and ichthyotoxicity. The allelopathic inhibitory effect of the A. catenella's supernatant was significantly enhanced when supernatants were obtained from co-cultures with direct contact between these species. We could not observe any allelopathic response provoked by H. akashiwo. On the other hand, A. catenella was able to decrease the cell concentration of H. akashiwo and R. salina. Besides, allelopathy and ichthyotoxicity were found for A. catenella's supernant, being the allelopathic effect not related to saxitoxin. These results reinforce the hypothesis that the allelopathic effect being regulated by the presence of other microalgae and could be responsible for ichthyotoxicity.

Bioherbicidal potential of plant species with allelopathic effects on the weed Bidens bipinnata L.

Plant species with allelopathic effects against weeds have emerged as a potential strategy for the development of ecologically friendly bioherbicides. In this study, the allelopathic effects of the plant species Dipteryx lacunifera Ducke, Ricinus communis L., Piper tuberculatum Jacq., and Jatropha gossypiifolia L. on the weed Bidens bipinnata L. were investigated. In vitro bioassays revealed that aqueous extracts of selected plant species were able to inhibit seed germination and seedling growth of B. bipinnata, highlighting the strongest allelopathic effect evidenced by R. communis. The phytotoxicity of the aqueous extracts was evaluated in pot experiments, which indicated that the foliar application of R. communis and P. tuberculatum extracts on B. bipinnata plants caused yellowing of leaves, affecting the chlorophyll content and reducing growth. The discrimination of the plant extracts by attenuated total reflectance Fourier transform mid-infrared (ATR FT-MIR) spectroscopy combined with principal component analysis (PCA) indicated the presence of allelochemical compounds, such as phenolics and terpenoids, which may be associated with allelopathic activity. Overall, this study provides valuable information about the substantial allelopathic inhibitory effects of the plant species R. communis and P. tuberculatum on the weed B. bipinnata, which may be used for the development of eco-friendly bioherbicides.

Allelopathic inhibitory effect on the growth of microcystis aeruginosa by improved ultrasonic-cellulase extract of Vallisneria

The unique and efficient characteristics of allelopathy in submerged plants make it an environmentally friendly method to control harmful algal blooms. Increased research focus has been placed on the improved allelochemical extraction methods of submerged plants because of their cost-utility relationships. In this study, the growth inhibition effect of Vallisneria extract on Microcystis aeruginosa (M. aeruginosa) cells through the combination of enzyme and ultrasonic-assisted extraction method was analyzed. By establishing a co-cultivation experiment, the growth indicators, photosynthetic system, and oxidative stress system of M. aeruginosa were determined. The reactive oxygen species (ROS) and superoxide dismutase (SOD) activity, as well as the catalase (CAT) and Malondialdehyde (MDA) levels of algal cells were found to have increased significantly after co-cultivation, which indicated that the Vallisneria ultrasonic-cellulase extract could induce oxidative stress in Microcystis aeruginosa cells. The Vallisneria extract could promote at low concentrations and inhibit at high concentrations on the growth of Microcystis aeruginosa. The effective suppression of growth of algae cells with the extract was observed at 5 g/L (fresh weight). The results showed that the Vallisneria ultrasonic-cellulase extract had a significant inhibitory effect on M. aeruginosa, making the effective ingredients a useful reference for algae inhibitors.

Diagnostic significance of the synthesis of phenolic compounds and proline in the leaves of Schisandra chinensis and Actinidia arguta for the indication of the stress levels of plants under conditions of mixed plantings

The peculiarities of the accumulation of polyphenolic compounds and free proline were investigated in the leaves of Actinidia arguta and Shisandra chinensis during their cultivation in vegetation containers with different ratios of the number of plants, namely 1 : 1, 2 : 1, 1 : 2. Monocultural (single-species) planting was used as a control. The content of free proline in plant leaves was carried out according to the method, which is based on the interaction of proline with a ninhydrin reagent, forming a pink-red color. The amount of polyphenolic compounds was determined by the Folin-Ciocalteu method. It was found that the ratio of plants grown together significantly affects the accumulation of primary and secondary metabolites in their leaves. Under conditions of mixed planting, more proline and phenolic substances are accumulated in plant leaves compared to monoculture. The maximum proline content, 19.44 ± 0.91 mg/g of dry weight (DW), was observed in the leaves of A. arguta in the experiment combination with a prevailing number of schisandra plants at a ratio of S. chinensis and A. arguta plants of 2:1. In the same combination, the leaves of actinidia contained the highest amount of phenolic compounds (36.87 ± 2.22 mg/g DW). The studied root exudates of the experimental plants had an allelopathic inhibitory effect on the test culture. The exudates caused 12.0 % average decrease in root growth of A. arguta test objects, and 30.0 % average decrease in root growth of S. chinensis test objects compared with the control. This allows us to conclude about the high activity of schisandra’s allelochemicals, which negatively affect the development of actinidia plants. The optimal ratio of plants A. arguta and S. chinensis when grown together is 2 : 1, since a higher concentration of schisandra plants in a container more stress in actinidia plants, expressed as an increased accumulation of phenols and prolines in its leaves. The result of a comparative analysis of the amount of proline and phenolic compounds can be used to assess the mutual influence of plants in mixed plantings to optimize their growing conditions, which confirms the diagnostic significance of these metabolites for indicating the stress state of the studied plants.

Parthenium a Noxious Weed: A Review on the Allelopathic Impact on Crop Plants and Their Management

Allelopathy is a chemical interaction between higher plants in which allelochemicals generated by donor plants can significantly alter – and in some cases, hinder – the development of recipient (test) plants. Allelopathy is thought to have a significant role in their fast spread. This is particularly true of invasive alien species (IAS) such as Ambrosia artemisiifolia and Sorghum halepense. Only a few weed species are known to have an allelopathic inhibitory effect among these dominant weeds. Parthenium hysterophorus L. is world's worst weed. Although it originated in tropical America, it has now spread quickly to Asia, Africa, Australia, and Europe. It can be controlled by herbicides, but their use adversely affects the environment and human health. It has been shown that extracts, residues and essential oils of many allelopathic plant species effectively control the germination and growth of Parthenium.

Changxun Fang. Pioneers of Allelopathy: Wenxiong Lin

Wenxiong Lin did research for &gt; 30 years in plant molecular ecology and agro-ecology, rice allelopathy and continuous monoculture problems/soil sickness of Chinese medicinal plants. His 20 Patents and most publications (about 100) have focussed on (i). Gene regulation of allelochemicals biosynthesis in allelopathic rice, (ii). allelopathic inhibitory effects on weeds, (iii). continuous monoculture problems/soil sickness in medicinal plants and (iv). the influence of allelochemicals and monoculture practice on the rhizospheric micro-environment. He helped in development of microbial fertilizer to alleviate the autotoxicity problem in continuous cropping of Radix pseudostellariae and Rehmannia glutinosa, etc. He had been the President of Asian Allelopathy Society, and got the outstanding achievement from the platform of International Allelopathy Foundation. His student, Dr. Changxun Fang got Rice Award and Grodzinsky Award respectively in the 6th and 8th World Congress of International Allelopathy Society. His elucidation of the molecular ecological mechanism of rice allelopathy was awarded the II Class Prize of Fujian Provincial Scientific and Technological Progress Award in 2007. His researches to find the mechanism of development of continuous cropping obstacle/soil sickness in R. pseudostellariae and its remedy was awarded the I Class Prize of Fujian Provincial Scientific and Technological Progress Award in 2020.

Allelopathic effect of Artemisia argyi on the germination and growth of various weeds

Allelopathy means that one plant produces chemical substances to affect the growth and development of other plants. Usually, allelochemicals can stimulate or inhibit the germination and growth of plants, which have been considered as potential strategy for drug development of environmentally friendly biological herbicides. Obviously, the discovery of plant materials with extensive sources, low cost and markedly allelopathic effect will have far-reaching ecological impacts as the biological herbicide. At present, a large number of researches have already reported that certain plant-derived allelochemicals can inhibit weed growth. In this study, the allelopathic effect of Artemisia argyi was investigated via a series of laboratory experiments and field trial. Firstly, water-soluble extracts exhibited the strongest allelopathic inhibitory effects on various plants under incubator conditions, after the different extracts authenticated by UPLC-Q-TOF-MS. Then, the allelopathic effect of the A. argyi was systematacially evaluated on the seed germination and growth of Brassica pekinensis, Lactuca sativa, Oryza sativa, Portulaca oleracea, Oxalis corniculata and Setaria viridis in pot experiments, it suggested that the A. argyi could inhibit both dicotyledons and monocotyledons not only by seed germination but also by seedling growth. Furthermore, field trial showed that the A. argyi significantly inhibited the growth of weeds in Chrysanthemum morifolium field with no adverse effect on the growth of C. morifolium. At last, RNA-Seq analysis and key gene detection analysis indicated that A.argyi inhibited the germination and growth of weed via multi-targets and multi-paths while the inhibiting of chlorophyll synthesis of target plants was one of the key mechanisms. In summary, the A. argyi was confirmed as a potential raw material for the development of preventive herbicides against various weeds in this research. Importantly, this discovery maybe provide scientific evidence for the research and development of environmentally friendly herbicides in the future.

Potential risks of nicotine on the germination, growth, and nutritional properties of broad bean

This study evaluated the allelopathy, uptake and accumulation, and potential agricultural and food safety risks of nicotine in broad bean (Vicia faba L.) during seed germination and seedling growth. Nicotine stress has an allelopathic inhibitory effect on seeds and a hormesis effect on germinated seeds and seedlings, which has an enhancement effect (<50 mg kg−1) and an inhibition effect (>100 mg kg−1) on the germinated seeds and an enhancement effect (<100 mg kg−1) and an inhibition effect (>200 mg kg−1) on the seedlings. Exogenous nicotine can be absorbed by broad bean roots from nicotine-contaminated soil and accumulated in the main organs of the seedlings, especially the leaves, which exceeded the maximum residue level (0.03 mg kg−1 DW) at 50 mg kg−1. Moreover, nicotine resulted in a bitter taste in the edible broad bean leaves, disrupting the balance of basic nutritional properties, decreasing sucrose, and increasing bitter substances such as choline and procyanidin. These results demonstrated that residual nicotine in the soil not only poses potential risks to sustainable agricultural development but also a food safety risk for consumers. The present study provides insight into the potential risks of nicotine in agroecosystems.

Allelopathy of rape on seed germination and seedling growth of three crops

Rape is an important green manure crop in China. It could increase soil fertility, but might have allelopathic effect on subsequent crops. We examined the effects of rape water-extract (at 0.025, 0.05 and 0.1 g·mL-1 concentrations) on seed germination, seedling growth, physiology and biochemistry of three crops including oat (Avena sativa), corn (Zea mays), and sunflower (Helianthus annuus). The results showed that water extract of rape did not affect seed germination rate of three crops. Oat had a trend of "low promotion and high inhibition", while sunflower had a trend of inhibition. High concentration of rape water extract inhibited root and stem length of oat seedling, corn seedling stem length and sunflower seedling root length, while low concentration treatment promoted root and stem length of corn seedling. The highest protein contents in oats and sunflower presented at the treatment of 0.05 g·mL-1, and that of corn at the treatment of 0.025 g·mL-1, which were significantly higher than that of control. The proline contents in sunflower decreased significantly in different treatments, while the proline content of corn was significantly higher than that of control at 0.05 g·mL-1. POD activity of corn was at a maximum at 0.05 g·mL-1, and that of sunflower was at 0.025 g·mL-1, which were significantly higher than control. There was no significant difference between control and other concentration treatments. The SOD activity of oat was significantly decreased at 0.025 g·mL-1. There was no significant difference in CAT activity between the three crops and the control. The MDA content in sunflower seedlings increased significantly at 0.1 g·mL-1, while that in corn seedlings was significantly lower than control. Our results indicated that the allelopathic inhibitory effect of rape water extract was the strongest on sunflower, followed by corn and oat.

Allelopathic Effects of Imperata Cylindrica Aqueous Extract on the Germination of Cucumis Sativus and Lolium Perenne

In this study, the allelopathic effect of Imperata cylindrica has been investigated. Aqueous extracts of Imperata cylindrica were tested at concentrations of 31.25, 62.5, and 125 mg/ml to study different parameters on Cucumis sativus and Lolium perenne. Various factors were studied to determine the inhibition and growth of root and shoot length, percentage germination, and fresh and dry weight. Results indicated that the aqeous extract of Imperata cylindrica contain allelochemicals which may contribute to its invasiveness and extreme competitiveness. The results of this study show that Imperata cylindrica contains allelochemical compounds particularly in root and shoot extracts that might be the potential candidates for future investigations for the development of herbicides based on its secondary metabolites and their allelopathic inhibitory effects. Further research is needed to investigate the allelopathic effect of Imperata cylindrical aqueous extracts under field conditions against the associated weed species and elucidation of the mechanism of inhibition involved

Biodeterioration Patterns and Their Interpretation for Potential Applications to Stone Conservation: A Hypothesis from Allelopathic Inhibitory Effects of Lichens on the Caestia Pyramid (Rome)

The colonisation of stone by different organisms often leaves biodeterioration patterns (BPs) on the surfaces even if their presence is no longer detectable. Peculiar weathering patterns on monuments and rocks, such as pitting phenomena, were recognised as a source of information on past colonisers and environmental conditions. The evident inhibition areas for new bio-patinas observed on the marble blocks of the Caestia Pyramid in Rome, recognisable as tracks of previous colonisations, seem a source for developing new natural products suitable for restoration activities. To hypothesise past occurring communities and species, which gave rise to such BPs, we carried out both in situ observations and analyses of the rich historical available iconography (mainly photographs). Moreover, we analysed literature on the lichen species colonising carbonate stones used in Roman sites. Considering morphology, biochemical properties and historical data on 90 lichen species already reported in Latium archaeological sites, we suppose lichen species belonging to the genus Circinaria (Aspicilia s.l.) to be the main aetiological agent of such peculiar BPs. These results seem relevant to highlight the long-lasting allelopathic properties of some lichen substances potentially applicable as a natural product to control colonisation, improving the environmental and economical sustainability of stone restoration.

Allelopathically inhibitory effects of eucalyptus extracts on the growth of Microcystis aeruginosa

Microcystis aeruginosa (M. aeruginosa), as the dominant algae in eutrophic water bodies, has caused a serious harm to the local eco-environment. A biological tool, employing allelopathic inhibitory of eucalyptus to control M. aeruginosa, has been receiving tremendous attention. This work presents the results of the allelopathic inhibitory effects of eucalyptus (Eucalyptus grandis × E.urophylla ‘GLGU9’) extracts of roots (ERE), stems (ESE), and leaves (ELE) on culture solutions of M. aeruginosa and its eco-physiological mechanism. The inhibitory effects of the extracts on the growth of M. aeruginosa varied greatly with ELE exhibiting the highest level of potency. Modes of action by which ELE inhibited M. aeruginosa growth were established. They involved reduction in photosynthesis, disruption of the cell membrane integrity, and inhibition of esterase activities of the cyanobacterial cells. However, ELE did not exhibit any gradients of toxicity towards zebrafish nor Washington grass plant. Species abundance and diversity in the systems remained likewise unaffected by ELE. The synergistic interaction between ELE and single-component allelochemicals (e.g., gallic acid and berberine) was ascribed to the increase in efficacy of allelochemicals in the various systems. The results of this study provide an underlying, novel, and attractive approach for controlling the growth of M. aeruginosa in aquatic environments.

The effects of Triplochiton scleroxylon aqueous extracts on initial growth of some vegetable crops in Ghana

The effect of Triplochiton scleroxylon (wawa) aqueousextracts were tested on the seeds of tomato (Lycopersicumesculentum), pepper (Capsicum annuum ) and garden egg (Solanummelongena ) in the pathology laboratory of the Forestry Research Institute of Ghana (FORIG). Aqueous extracts of T. scleroxylon leaves (L) and roots (R) were prepared at different concentrations of 2%, 4%, 6%, and 8% and applied to the seeds. The effects of these treatments were assessed in a Completely Randomized Design (CRD) with 4 replications. The findings showed that all the vegetable crops were affected by the different concentrations of the leaf and roots aqueous extracts (P&lt;0.05). Tukey-Kramer multiple comparison indicated that the inhibitory effect was positively correlated with concentration of the extracts. The higher extract concentrations (6%-8%) had stronger inhibitory effect whereas; in some cases the lower concentration (2%-4%) showed stimulatory effect during germination. The radicles were more susceptible to the effect of the extracts than the plumules. The germination of L.esculentum was highly inhibited in growth by 51.4% in both the leaf and root extracts. Similarly, C.annuum recorded the highest inhibitory effect on radicle length by 72.5% in the leaf extract whilst, the highest inhibitory effects in plumule was 44%. The overall results point to an allelopathic inhibitory effect of T. scleroxylon on the three vegetable crops.

Comparative Phytotoxicity of Aqueous Extracts of Centaurea maculosa and Melilotus officinalis on Germinability and Growth of Wheat

Abstract Weed incursion in cultivated fields is a serious biological problem, which causes considerable yield losses of economically important field crops through allelopathy and competitive interactions. Spotted knapweed (Centaurea maculosa) and yellow melilot (Melilotus officinalis) are among the most prevalent weeds in cultivated fields of Pakistan, particularly in wheat fields. Like many other weeds, they may pose allelopathic and competitive challenges to field crops. The objective of this study was to evaluate allelopathic potentials of the two weeds on germination and seedling growth of wheat under laboratory conditions. Amounts of 15, 20, 25 and 30% concentrated leaf aqueous extracts of C. maculosa and M. officinalis were prepared and tested for their effects on germination percentage, radicle and coleoptile lengths of wheat. Germination, radicle and coleoptile lengths of test crop declined significantly at higher concentration (25-30%) of the extracts of two weeds. However, concentration of M. officinalis up to 20% had either no effect or stimulatory effects on the studied growth characteristics of wheat. Highest germination inhibition and decreased seedling growth were caused by leaf extracts of C. maculosa at 30% extract concentration. Growth inhibition was generally dependent on the extract concentration. The study indicated that both plant exhibited allelopathic activity and growth inhibitory effects on wheat at higher concentration; however, extracts of C. maculosa were more phytoinhibitory than M. officinalis. The weeds could serve as potent allelopathic plants for management of other weeds.

Inhibitory action of allelochemicals from Artemisia nanschanica to control Pedicularis kansuensis, an annual weed of alpine grasslands

The inhibitory action of allelochemicals can be used effectively for biological weed management and can minimise environmental impacts related to herbicides. The aim of the present study was to identify allelochemicals of Artemisia nanschanica Krasch, a typical weed with strong allelopathic effects, that could potentially control Pedicularis kansuensis Maxim, the key pioneer weed that causes rapid degradation of alpine pastures. Gas chromatography and mass spectrometry were used to identify the compounds of six extracts from A. nanschanica. Two ethyl acetate extracts were the most effective in reducing the seed germination rate and in inhibiting seedling shoot and root growth of P. kansuensis. Three chemical compounds from the ethyl acetate extracts were identified for their allelopathic inhibitory effects, a sesquiterpene and two aromadendrene oxides, with the sesquiterpene being the most effective. The three compounds showed the best inhibitory effect through synergistic action. We concluded that the three allelochemicals of A. nanschanica, either alone or in combination, can be used to biologically control P. kansuensis in alpine pastures on the Tibetan plateau.

ATIVIDADES ANTIOXIDANTE E ALELOPÁTICA DE EXTRATOS FOLIARES OBTIDOS DE EUGENIA DYSENTERICA

The aim of this study was to evaluate the antioxidant and allelopathic potential of ethanolic and hydroalcoholic 70:30 and 50:50 (ethanol: water) extracts from the leaves of Eugenia dysenterica. The antioxidant activity of the extracts were evaluated by applying the free radical scavenging method using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The allelopathic bioassays were carried out in laboratory, considering germination percentage, Index of Germination Speed (IVG), radicle / primary root length and hypocotyl / coleoptile length of lettuce and corn seeds. All parameters underwent variance analysis, and the mean values were compared by means of Scott-Knott test (p less then 5%). In relation to the antioxidant potential all extracts showed activity, with inhibitory concentration (IC50) at 0.73; 1.68 e 1.83mg/mL for the ethanolic, hydroalcoholic 70:30 e hydroalcoholic 50:50, respectively. Regarding allelopathic activity, all extracts reduced the IVG of lettuce and inhibit the radicle / primary root growth and hypocotyl / coleoptile of target species. Therefore, the extracts tested of E. dysenterica showed antioxidant potential and allelopathic inhibitory effect on the initial development of lettuce and corn

Potential allelopathic inhibitory effect of Salix nigra on growth of Triticum aestivum

Potential allelopathic inhibitory effect of Salix nigra on growth of Triticum aestivum