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Bacterial wilt is a significant soil-borne disease that poses a threat to mulberry production yield and quality of agricultural production worldwide. However, the disease resistance mechanisms dependent on root exudates are not well understood. In this present study, we investigated the antibacterial mechanisms of the main active substances (erucamide, oleamide, and camphor bromide) present in mulberry root exudates (MRE) against Ralstonia pseudosolanacearum (Rp), the causal agent of bacterial wilt. Our findings revealed that these three active substances inhibited the growth activity of Rp by affecting the cell morphology and extracellular polysaccharide content, as well as triggering a burst of reactive oxygen species. The active substances induced oxidative stress, leading to a decrease in Rp growth. Additionally, the expression levels of key genes in the hrp gene cluster (hrpB, hrpX, and hrpF) and other virulence-related genes (such as ripAW, ripAE, Rs5-4819, Rs5-4374, ace, egl3, and pehB) were significantly reduced upon treatment with the active substances. Further pathogenicity experiments demonstrated that root exudates (at a concentration of 1.5 mg·mL−1) delayed or slowed down the occurrence of bacterial wilt in mulberry. These findings provide valuable insight into the antimicrobial mechanisms of MRE against Rp and lay a theoretical foundation for the development and application of biocontrol agents to control mulberry bacterial wilt. [ABSTRACT FROM AUTHOR]

Bacteriocins may be used as natural preservatives and antibiotic substitutes in various foods. However, the multistep purification process of bacteriocins results in high production costs, which is an obstacle to their commercial use and consumer accessibility. In this study, a bacteriocin-like inhibitory substance (BLIS) from Bacillus spp. isolated from Korean fermented foods was partially purified using the aqueous two-phase system (ATPS). The maximum activity of the BLIS was achieved for ATPS composed of PEG 1000 (15% [w/w])/ammonium sulfate (20% [w/w])/sodium chloride (2% [w/w]), which caused BLIS activity to increase by 3 times with a 99% recovery rate. In particular, B. amyloliquefaciens Y138-6 BLIS exhibited broad antibacterial activity, high resistance to acid-base stress, and excellent thermal stability. This antibacterial substance inhibited the growth of aerobic bacteria and fungi on the walls of cheese and ripening rooms. These antibacterial properties have been shown to increase food safety and have the potential for use as biopreservatives. Moreover, considering that the execution of the ATPS requires only salts and PEG, it is a simple, environmentally friendly, and cost-effective process and may have industrial applications in the recovery of BLIS from fermentation broth. [ABSTRACT FROM AUTHOR]

The aim of this study was to enhance the shoot production of date palm, Hayani cv. by investigating the effect of adding jatropha leaves extract in appropriate doses to the germination and multiplication media of date palm. a small cluster of 7-10 matured somatic embryos of date palm Hayani cv. were grown for 12 weeks on MS medium with 0.5 mg l-1 BA, 0.1 mg l-1 NAA and 10.0 ml l-1 JLE which produced the highest number of somatic embryos (28.3 embryos/jar), with the maximum number of leaves (34.5 leaf/jar) with the longest leaf length (6.0 cm). furthermore; during shoot multiplication stage, clusters of shoots cultivated on MS basal medium supplemented with 1.0 mg l-1 BA, 0.5 mg l-1 TDZ and 0.25 mg l-1 NAA with 10 ml l-1 JLE resulted in the best shoot regeneration, with maximum number of shoots (25.2 shoots/jar), the maximum number of leaves (56.0 leaf/jar), and the longest leaf length (5.0 cm). The regenerated shoots with lengths of 5-7 cm were grown on 1/2 MS medium with 1.0 mg l-1 NAA during the rooting stage. [ABSTRACT FROM AUTHOR]

Bacteria have a tendency to form multicellular biofilms, which adhere to surfaces and contain extracellular polymeric substances (EPS). This tendency is accompanied by hydrophobic interactions, which are vital in the biofilm attachment process. Oral biofilms contribute to a range of oral health issues, including gingivitis, dental caries, and halitosis. Therefore, this research aimed to investigate the correlation between oral biofilm growth inhibition and hydrophobicity reduction in Streptococcus mutants, Streptococcus sanguinis, Lactobacillus acidophilus, and Actinomyces viscosus. Essential oil-derived compounds, namely eugenol, C-10 massoia lactone, thymol, cinnamaldehyde, and zerumbone, were applied in the experiment. A microdilution assay using crystal violet staining evaluated the oral microbes' biofilm growth. The adhesion of microbes to hexadecane was measured to assess hydrophobicity reduction, which was analyzed correlatively using PAST (Paleontological Statistics) software and the Principal Component Analysis (PCA) method. The results showed a positive correlation of the hydrophobicity reduction towards the biofilm formation inhibition for all tested microbes (graphical angle <45°). The Principal Component (PC) analysis, based on the eigene values, showed that PC1 and PC2 accounted for 54.149% and 25.652% of the total variation, respectively. These two components explained 79.801% of the total variation, indicating a significant level of variability. This finding supported the notion that a greater reduction in microbial hydrophobicity was associated with stronger inhibitory activity against planktonic growth. The hydrophobicity reduction assay may indicate a potential of bioactive compounds against biofilm growth inhibition of oral microbes [ABSTRACT FROM AUTHOR]

Introduction: Solanum rostratum, an annual malignant weed, has seriously damaged the ecological environment and biodiversity of invasion area. This alien plant gains a competitive advantage by producing some new phytotoxic substances to inhibit the growth of native plants, thus achieving successful invasion. However, the chemical structures, inhibitory functions and action mechanisms of phytotoxic substances of S. rostratum remain unclear. Methods: In this study, to clarify the chemical structures of phytotoxic substances from S. rostratum, we isolated phenylpropanoid amides from the plant. Their structures were identified by comprehensive HR-ESIMS, NMR and ECD data. And the inhibitory functions of isolated phenylpropanoid amides on one model plant (Arabidopsis thaliana) were also investigated. In addition, the action mechanisms of active phenylpropanoid amides were revealed by antioxidant-related enzymes [Catalase (CAT), Peroxidase (POD), Superoxide dismutase (SOD)] activities and corresponding molecular docking analyses. Results and Discussion: Phytochemical research on the whole plant of S. rostratum led to the isolation and identification of four new phenylpropanoid amides (1-4), together with two known analogues (5-6). All the compounds showed phytotoxic effects with varying levels on the seed germination and root elongation of one model plant (Arabidopsis thaliana), especially compound 2 and 4. Likewise, compounds 2 and 4 displayed potent inhibitory effects on antioxidant-related enzyme (POD). In addition, compounds 2 and 4 formed common conventional hydrogen bonds with residues Ala34 and Ser35 in POD revealed by molecular docking analyses. These findings not only helped to reveal the invasion mechanism of S. rostratum from the perspective of "novel weapons hypothesis", but also opened up new ways for the exploitation and utilization of S. rostratum. [ABSTRACT FROM AUTHOR]

Solid-based residues (SBRs) of Cordyceps militaris are often considered as waste after the cultivation of the fruiting body. To demonstrate the value of this by-product, different ratios of two favorable green solvents (EtOH and water) were employed to optimize the yields of cordycepin (Cor) and adenosine (Ado) and investigate relevant activities of plant growth inhibition (allelopathy), antioxidants, and xanthine oxidase. The SBR extracts of 60% EtOH-40% water (W4) and 40% EtOH-60% water (W6) exhibited the highest antioxidant activity as well as yielded the optimum content of Cor and Ado. The W4 and Wt (hot water) exhibited maximum inhibitory effects on the growth of Raphanus sativus (radish), Lactuca sativa (lettuce) and two noxious weeds, Echinochloa crus-galli (barnyard grass) and Bidens pilosa (beggarticks). Furthermore, GC-MS scan analysis revealed the presence of 14 major compounds in the SBRs. W4 is the best solvent to optimize yields of Cor and Ado, as well as having the strongest levels of antioxidant activity, xanthine oxidase, and growth-inhibitory activity. This study reveals that SBRs are a potential source of medicinal and agricultural utilization. [ABSTRACT FROM AUTHOR]

Invasive tree species are a significant threat to native flora. They modify the environment with their allelopathic substances and inhibit the growth of native species by shading, thus reducing diversity. The most effective way to control invasive plants is to prevent their spread which requires identifying the environmental parameters promoting it. Since there are several types of invasive plant databases available, determining which database type is the most relevant for investigating the occurrence of alien plants is of great importance. In this study, we compared the efficiency and reliability of point-based (EUROSTAT Land Use and Coverage Area Frame Survey (LUCAS)) and polygon-based (National Forestry Database (NFD)) databases using geostatistical methods in ArcGIS software. We also investigated the occurrence of three invasive tree species (Ailanthus altissima, Elaeagnus angustifolia, and Robinia pseudoacacia) and their relationships with soil, hydrological, and climatic parameters such as soil organic matter content, pH, calcium carbonate content, rooting depth, water-holding capacity, distance from the nearest surface water, groundwater depth, mean annual temperature, and mean annual precipitation with generalized linear models in R-studio software. Our results show that the invasion levels of the tree species under study are generally over-represented in the LUCAS point-based vegetation maps, and the point-based database requires a dataset with a larger number of samples to be reliable. Regarding the polygon-based database, we found that the occurrence of the invasive species is generally related to the investigated soil and hydrological and climatic factors. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study is to investigate anticancer activity of Brassica oleracea var. alboglabra (BOA) against the proliferation of BGC-823 human gastric cancer cells. Materials and Methods: B. oleracea var. alboglabra was extracted by ethanol 98% at a solid-to-liquid ratio of 1:8, (w/v) for 24h at room temperature. The cytotoxic effect of vegetables was examined by MTT assay. The migration of the cancer cells was conducted by wound healing assay and visualized under an inverted microscope. The mRNA expression level was quantified by real time PCR. Major Findings: It was found that ethanol extract of BOA exhibited the inhibitory activity against the proliferation of BGC-823 cells at IC50 value of 217.6 ± 2.8 µg/ml. Moreover, the treatment of BOA extract at concentration of 100 µg/ml for 24 h significantly suppressed the migration of gastric cancer cells into the gap as compared to the untreated cell group. Notably, the cytotoxic effect of BOA extract on human gastric cancer cells was found due to induction of apoptosis, mediating the up-regulation of caspase-8, -9, -3, and Bax in cancer cells. Conclusion: These results indicated that B. oleracea var. alboglabra have the potential inhibitory activity against the development of gastric cancer. [ABSTRACT FROM AUTHOR]

Root rot is a common disease, that severely affects the yield and quality of alfalfa. Biocontrol is widely used to control plant diseases caused by pathogenic fungi, however, biocontrol strains for alfalfa root rot are very limited. In this study, a Bacillus subtilis CG-6 strain with a significant biocontrol effect on alfalfa root rot was isolated. CG-6 secretes antibacterial enzymes and siderophore, phosphate solubilization and indoleacetic acid (IAA). The inhibition rate of strain CG-6 against Fusarium oxysporum was 87.33%, and it showed broad-spectrum antifungal activity. Inoculation with CG-6 significantly reduced the incidence of alfalfa root rot, the control effect of greenhouse cultivation reached 58.12%, and CG-6 treatment significantly increased alfalfa plant height, root length, fresh weight, and dry weight. The treatment with CG-6 significantly increased the levels of antioxidant enzymes (catalase, peroxidase, superoxide dismutase, and lipoxygenase) in alfalfa leaves by 15.52%–34.03%. Defensive enzymes (chitinase and β-1,3-glucanase) increased by 24.37% and 28.08%, respectively. The expression levels of regulatory enzyme genes (MsCAT , MsPOD , MsCu, Zn-SOD1 , MsCu, Zn-SOD2 , MsCu, Zn-SOD3 , and MsLOX2) and systemic resistance genes (MsPR1 , MsPDF1.2 , and MsVSP2) increased by 0.50–2.85 fold, which were higher than those in the pathogen treatment group. Therefore, CG-6 could be used as a potential strain to develop biopesticides against alfalfa root rot. • Bacillus subtilis CG-6 was isolated from alfalfa rhizosphere soil. • CG-6 has strong inhibition effect on the growth of the pathogenic bacterium Fusarium oxysporum and can remarkably reduce the incidence rate of alfalfa root rot. • CG-6 could promote that growth of alfalfa. • CG-6 could secrete antibacterial substances such as cellulase to inhibit the growth of pathogenic bacteria. • CG-6 might activate JA-mediated signaling pathway to trigger plant defense. [ABSTRACT FROM AUTHOR]

This work aims to evaluation of the antifungal activity of dichloromethane essential oil of barks of Cinnamomum zeylanicum against black rot onions pathogenic fungi such as Penicillium sp and Aspergillus niger. The antifungal activity of essential oils of barks of Cinnamomum zeylanicum was tested in vitro by agar well diffusion method against plant pathogenic fungi strains vis Penicillium sp. and Aspergillus niger. The results showed that the essential oils of Cinnamomum zeylanicum exhibited the highest percentage of growth inhibition (100%) against Aspergillus niger and Penicillium sp at (1% v/v) and (2.5% v/v) minimum inhibitory concentration respectively. The ability of the extracts to inhibit the growth of the fungi is an indication of the antifungal potential of cinnamon, which make the candidate for production of antifungal agents. It can be applied in agricultural product for development of transgenic resistant to plant diseases. [ABSTRACT FROM AUTHOR]

Background: Peanut stem rot is a serious plant disease that causes great economic losses. At present, there are no effective measures to prevent or control the occurrence of this plant disease. Biological control is one of the most promising plant disease control measures. In this study, Pseudomonas chlororaphis subsp. aurantiaca strain zm-1, a bacterial strain with potential biocontrol properties isolated by our team from the rhizosphere soil of Anemarrhena asphodeloides, was studied to control this plant disease. Methods: We prepared extracts of Pseudomonas chloroaphis zm-1 extracellular antibacterial compounds (PECEs), determined their antifungal activities by confrontation assay, and identified their components by UPLC-MS/MS. The gene knockout strains were constructed by homologous recombination, and the biocontrol efficacy of P. chlororaphis zm-1 and its mutant strains were evaluated by pot experiments under greenhouse conditions and plot experiments, respectively. Results: P. chlororaphis zm-1 could produce extracellular antifungal substances and inhibit the growth of Sclerotium rolfsii, the main pathogenic fungus causing peanut stem rot. The components of PECEs identified by UPLC-MS/MS showed that three kinds of phenazine compounds, i.e., 1-hydroxyphenazine, phenazine-1-carboxylic acid (PCA), and the core phenazine, were the principal components. In particular, 1-hydroxyphenazine produced by P. chlororaphis zm-1 showed antifungal activities against S. rolfsii, but 2-hydroxyphenazine did not. This is quite different with the previously reported. The extracellular compounds of two mutant strains, ΔphzH and ΔphzE, was analysed and showed that ΔphzE did not produce any phenazine compounds, and ΔphzH no longer produced 1-hydroxyphenazine but could still produce PCA and phenazine. Furthermore, the antagonistic ability of ΔphzH declined, and that of ΔphzE was almost completely abolished. According to the results of pot experiments under greenhouse conditions, the biocontrol efficacy of ΔphzH dramatically declined to 47.21% compared with that of wild-type P. chlororaphis zm-1 (75.63%). Moreover, ΔphzE almost completely lost its ability to inhibit S. rolfsii (its biocontrol efficacy was reduced to 6.19%). The results of the larger plot experiments were also consistent with these results. Conclusions: P. chlororaphis zm-1 has the potential to prevent and control peanut stem rot disease. Phenazines produced and secreted by P. chlororaphis zm-1 play a key role in the control of peanut stem rot caused by S. rolfsii. These findings provide a new idea for the effective prevention and treatment of peanut stem rot. [ABSTRACT FROM AUTHOR]

The aim of the work was to improve the elements of garlic bulb storage technology by using hydrophobic protective coatings, growth inhibitors. The study allows you to choose protective coatings of garlic bulbs for long-term storage and extend the duration of storage. It has been found, that the loss of weight of garlic bulbs during storage depends on the method of storage and type of treatment of garlic plants. Weight loss during storage in boxes with polyethylene inserts is reduced by 2 times, bulbs, treated with paraffin, - by 3.4 times. Treatment of plants with maleic acid hydrazide (MAH) reduces weight loss by 1.7 times. After 6 months of storage, the loss due to dry matter ranged from 51.7 to 69.7 % of weight loss. It has been found, that the treatment of plants by MAH helps to reduce losses due to germination of bulbs, damage by microorganisms, drying compared to the control version and storage in boxes with polyethylene inserts. The highest yield of 91.8 % of commercial bulbs is provided by their treatment with paraffin. Analysis of variance showed that the method of storage affects the preservation of garlic by 98 %, the development of diseases - by 54 %. Treatment by MAH affected the germination of bulbs by 98 %. Based on the obtained results, a correlation analysis was performed and the linear dependence of the weight loss of winter garlic bulbs depending on the peculiarities of the storage method was established. [ABSTRACT FROM AUTHOR]

• Maillard reaction products (MRPs) retarded carp lipid oxidation and microbial growth. • MRPs inhibited Mb oxidation by maintaining Mb reduction and stabilizing heme iron. • MRPs delayed the carp deterioration of texture and flavor through antioxidant effect.. Lipid oxidation is the major cause of quality deterioration in freshwater fish, especially mediated by myoglobin (Mb). This study aimed to investigate the antioxidant mechanism of Maillard reaction products (MRPs) in Mb-mediated lipid oxidation in common carp (Cyprinus carpio). MRPs exhibited promising antioxidant and antimicrobial capacities based on the reduced content of peroxide and thiobarbituric acid-reactive substances and inhibited microbial growth. MRPs inhibited the oxidation of Mb by lowering the transfer from oxymyoglobin to metmyoglobin and improving the stability of heme iron. The correlation analysis showed that MRPs regulated the formation of free radicals by maintaining the reduced structure of Mb and the integrity of heme iron, and also directly inhibited the formation of oxidation products in a chain radical reaction. The texture and electronic nose analysis indicated that MRPs could delay the structural disruption and flavor deterioration of surimi. Therefore, MRPs could effectively inhibit Mb-induced lipid oxidation and further control the resulting changes in the flavor and texture of surimi. [ABSTRACT FROM AUTHOR]

Microbial diseases cause considerable losses in fruit and vegetable production both during the cultivation of plants and their manipulation, transport and storage. In order to sustain crops yield, farmers use synthetic pesticides that have a negative effect on the environment and human health. For this reason, antimicrobial research is mainly focused on the development of efficient and ecofriendly technologies involving the elimination or reduction of synthetic pesticides in agriculture. One solution is represented by the use of soil bacteria that produce antimicrobial substances to inhibit the growth of phytopathogenic microorganisms. In this context, the main goal of this study was to evaluate the antimicrobial activity of P3.3S strain in order to be used as a biocontrol agent. Thus, the antimicrobial activity of P3.3S strain was assessed using agar diffusion method. Two bacterial strains - Agrobacterium tumefaciens C58, Agrobacterium tumefaciens GV220 and also Rhizoctonia solani were used as test phytopathogenic microorganisms. The results indicate that P3.3S strain inhibits the growth of tested phytopathogens, with a higher inhibitory activity against strain GV220 compared with C58. The largest zone of inhibition was recorded at 72 hours. Strain P3.3S showed better inhibitory activity than kanamycin (100 µg/ml) which was used as positive control. Regarding antifungal activity, the culture of P3.3S showed the best inhibition of mycelial growth, followed by the supernatant and filtrate. The inhibitory activity of the filtrate may indicate that the strain P3.3S produces antimicrobial substances that are released in the medium. In conclusion, strain P3.3S has potential to be used as a biocontrol agent against the tested phytopathogens, but further studies are needed. [ABSTRACT FROM AUTHOR]

[Display omitted] Infections caused particularly by Candida glabrata are hard to treat due to the development of antifungal resistance that occurs mainly through the production of efflux pumps and biofilm. Thus, a promising strategy to overcome infections caused by C. glabrata could be to use a substance able to inhibit efflux pumps and eradicate biofilms. Lapachones are natural naphthoquinones that possess a variety of pharmacological properties. Previous studies show that these substances inhibit the growth, virulence factors and efflux pumps of C. albicans. The aim of the present study was to evaluate whether lapachones are able to inhibit efflux pumps related to antifungal resistance in C. glabrata and either prevent biofilm formation or affect mature biofilms. Assays were performed with Saccharomyces cerevisiae strains that overexpress C. glabrata transporters (CgCdr1p and CgCdr2p). One C. glabrata clinical isolate that overexpresses CgCdr1p was also used. Both β-lapachone and β-nor-lapachone affected the growth of S. cerevisiae and C. glabrata when combined to fluconazole, and this action was inhibited by ascorbic acid. Both lapachones stimulated ROS production, inhibited efflux activity, adhesion, biofilm formation and the metabolism of mature biofilms of C. glabrata. Data obtained on the present study point to the potential use of β-lapachone and β-nor-lapachone as antibiofilm agents and adjuvants on the antifungal therapy related to resistant infections caused by C. glabrata. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different carbon sources on the denitrification performance, soluble microbial products (SMPs), and microbial community in lab-scale denitrification biofilters (DNBFs) treating simulated secondary effluent. Three biofilters, named D 1 , D 2 , and D 3 , were fed with sufficient supplies of sodium acetate, methanol, and glucose, respectively. The denitrification efficiencies and denitrification rates of the three DNBFs followed the order D 2 > D 1 > D 3. The final effluent SMP concentrations were 26.24 ± 3.55 mg/L, 24.95 ± 2.67 mg/L, and 28.00 ± 2.44 mg/L in D 1 , D 2 , and D 3 , respectively. The results also showed that the proteins were the main components of SMPs. External carbon sources were also involved in the initial denitrification in D 1 and D 2 , while denitrifying bacteria were induced to utilize SMPs in D 3. The total relative abundance of these denitrifying bacteria followed the order D 1 > D 2 > D 3. Moreover, fluorescent soluble microbial byproduct-like substances inhibited the growth of functional bacteria, resulting in a decrease in denitrification efficiency. Therefore, because the SMPs also significantly affected nitrate removal in the DNBFs, their different components exhibited differing effects on denitrification. [Display omitted] • Biofilters D 1 and D 2 showed better denitrification performance than D 3. • Glucose as a carbon source was unfavorable to the effluent quality. • The protein like-substances in the SMPs contributed to total nitrogen removal. • The fluorescent soluble microbial byproduct-like substances in the SMPs inhibited the denitrification process. • The relative abundance of denitrification bacteria followed the order of D 1 > D 2 > D 3. [ABSTRACT FROM AUTHOR]

Aspergillus flavus is a common contaminant in grain, oil and their products. Its metabolite aflatoxin B1 (AFB1) has been proved to be highly carcinogenic. Therefore, it is of great importance to find possible antifungal substances to inhibit the growth and toxin production of Aspergillus flavus. Carvacrol (CV) was reported as a potent antifungal monoterpene derived from plants. In this paper, the antifungal effects and mechanism of CV on Aspergillus flavus were investigated. CV was shown good inhibition on the growth of Aspergillus flavus and the production of AFB1. CV used in concentrations ranging from 0, 50, 100 and 200 μg/mL inhibited the germination of spores, mycelia growth and AFB1 production dose-dependently. To explore the antifungal mechanism of CV on Aspergillus flavus, we also detected the ergosterol content of Aspergillus flavus mycelia, employed Scanning Electron Microscopy (SEM) to observe mycelia morphology and utilized Ultra-High-Performance Liquid Chromatography-High-Resolution Mass Spectrometry (UHPLC-HRMS) to explore the lipidome profiles of Aspergillus flavus. The results showed that the production of ergosterol of mycelia was reduced as the CV treatment concentration increased. SEM photographs demonstrated a rough surface and a reduction in the thickness of hyphae in Aspergillus flavus treated with CV (200 µg/mL). In positive ion mode, 21 lipids of Aspergillus flavus mycelium were downregulated, and 11 lipids were upregulated after treatment with 200-µg/mL CV. In negative ion mode, nine lipids of Aspergillus flavus mycelium were downregulated, and seven lipids upregulated after treatment with 200-µg/mL CV. In addition, the analysis of different lipid metabolic pathways between the control and 200-µg/mL CV-treated groups demonstrated that glycerophospholipid metabolism was the most enriched pathway related to CV treatment. [ABSTRACT FROM AUTHOR]

Ornamental plants are cultivated worldwide. Chrysanthemum is classified as one of the most important cut and potted flowers in most of the countries. The consumer's expectation is to find small–compact, and full of inflorescences plants. To meet these demands, growers are tending to use plant growth retardants. Three Chrysanthemum indicum L. varieties ('Smola White', 'Arber' and 'Vienna White') were assessed by using four plant growth regulators (PP–Bumper 250 EC; CC–Stabilan SL; MP–Medax Top SC; and PD–Toprex SC). Results indicate that treated plants show significant decrease in the assessed parameters, although in some cases growth could be a variety–dependent factor. It can also be concluded that retardants inhibit chrysanthemum growth. PD treatments greatly inhibited the growth of the plant, and also had a negative effect on inflorescences. In conclusion, the present work strengthens the possibility of using retardants as plant growth inhibitors in Chrysanthemum cultivation. [ABSTRACT FROM AUTHOR]