Inhibition Of Seed Germination Research Articles

Nitric Oxide is Involved in the Inhibition of Seed Germination by Paclobutrazol in Arabidopsis

Nitric Oxide is Involved in the Inhibition of Seed Germination by Paclobutrazol in Arabidopsis

Pectin methylesterase 31 is transcriptionally repressed by ABI5 to negatively regulate ABA-mediated inhibition of seed germination.

Pectin methylesterase (PME), a family of enzymes that catalyze the demethylation of pectin, influences seed germination. Phytohormone abscisic acid (ABA) inhibits seed germination. However, little is known about the function of PMEs in response to ABA-mediated seed germination. In this study, we found the role of PME31 in response to ABA-mediated inhibition of seed germination. The expression of PME31 is prominent in the embryo and is repressed by ABA treatment. Phenotype analysis showed that disruption of PME31 increases ABA-mediated inhibition of seed germination, whereas overexpression of PME31 attenuates this effect. Further study found that ABI5, an ABA signaling bZIP transcription factor, is identified as an upstream regulator of PME31. Genetic analysis showed that PME31 functions downstream of ABI5 in ABA-mediated seed germination. Detailed studies showed that ABI5 directly binds to the PME31 promoter and inhibits its expression. In the plants, PME31 expression is reduced by ABI5 in ABA-mediated seed germination. Taken together, PME31 is transcriptionally inhibited by ABI5 and negatively regulates ABA-mediated seed germination inhibition. These findings shed new light on the mechanisms of PMEs in response to ABA-mediated seed germination.

Comparative efficacy of two Kokilaksha Formulations vis-a-vis Vinblastine, using Seed Germination Inhibition

Seed germination inhibition was previously demonstrated as a simple preliminary method for the identification of potential anticancer compounds. Studies conducted by us have indicated that horse gram (Macrotyloma uniflorum) germination was inhibited significantly, by the herbal drug termed HST-K derived from Asteracantha longifolia. Presently we have determined the EC-50 values of the same drug and along with a commercially available formulation of Kokilaksha using the seed-based assay method and expressed these values as equivalents of vinblastine. Efficacy of the HST-K drug was found to be 2.3, 3.1 and 1.6 fold greater than the commercially available formulation of Kokilaksha with respect to the retardation of seed weight, amylolytic and alkaline phosphatase activities respectively. The EC-50 value for vinblastine with respect to seed weight inhibition was calculated as 0.07mg/ml which corresponded to the 49.2-fold diluted HST-K extract. Likewise, the 117.- fold and 88.7-fold diluted HST-K drug formulation was found to be equivalent to 0.05mg/ml and 0.04mg/ml of vinblastine in terms of EC-50 values for amylolytic and alkaline phosphatase activities respectively. The HST-K extract was thus more efficacious than the commercially used formulation of Kokilaksha as evidenced by our present studies.

Study of Sambiloto Andrographis paniculate Ness. Extract as an Eco-Friendly Biocontrol on Weed Seed Germination and Growth

The use of synthetic herbicides causes many problems, including pollution, a decrease in soil organic content, and weed resistance to specific herbicides. Plants provide a source of novel phytotoxic compounds that can be evaluated in the search for efficient and ecologically safe herbicides. This research aimed to examine the allelochemical bioherbicidal activity of sambiloto (Andrographis paniculate Ness) leaf extract (SLE) to suppress weed seed germination and growth. The experiment was designed to investigate the effect of the SLE as a potent weed seed germination inhibitor and retard weed growth. In this experiment, a non-factorial randomized block design was used, with treatments SLE0 (0% Extract), SLE1 (Extract 0.1%), SLE2 (Extract 0.5%), SLE3 (Extract 1.0%), and SLE4 (Extract 1.5%). The result showed that weed height and biomass were significantly reduced after the extract was applied. The plant-based extracts contained 0.1114% flavonoids and 0.1628% tannins. The findings suggest that this sambiloto herbaceous extract has a promising future in modern plant protection as bioherbicide to suppress germination and weed growth. Therefore, the application of these bio-products could be beneficial for sustainable agricultural practices.

Nuclear factor OsNF-YC5 modulates rice seed germination by regulating synergistic hormone signaling.

Regulation of seed dormancy/germination is of great importance for seedling establishment and crop production. Nuclear factor-Y (NF-Y) transcription factors regulate plant growth and development, as well as stress responses; however, their roles in seed germination remain largely unknown. In this study, we reported that NF-Y gene OsNF-YC5 knockout increased, while its overexpression reduced, the seed germination in rice (Oryza sativa L.). ABA-induced seed germination inhibition assays showed that the osnf-yc5 mutant was less sensitive but OsNF-YC5-overexpressing lines were more sensitive to exogenous ABA than the wild type. Meanwhile, MeJA treatment substantially enhanced the ABA sensitivity of OsNF-YC5-overexpressing lines during seed germination. Mechanistic investigations revealed that the interaction of OSMOTIC STRESS/ABA-ACTIVATED PROTEIN KINASE 9 (SAPK9) with OsNF-YC5 enhanced the stability of OsNF-YC5 by protein phosphorylation, while the interaction between JASMONATE ZIM-domain protein 9 (OsJAZ9) and OsNF-YC5 repressed OsNF-YC5 transcriptional activity and promoted its degradation. Furthermore, OsNF-YC5 transcriptionally activated ABA catabolic gene OsABA8ox3, reducing ABA levels in germinating seeds. However, the transcriptional regulation of OsABA8ox3 by OsNF-YC5 was repressed by addition of OsJAZ9. Notably, OsNF-YC5 improved seed germination under salinity conditions. Further investigation showed that OsNF-YC5 activated the high-affinity K+ transporter gene (OsHAK21) expression, and addition of SAPK9 could increase the transcriptional regulation of OsHAK21 by OsNF-YC5, thus substantially reducing the ROS levels to enhance seed germination under salt stress. Our findings establish that OsNF-YC5 integrates ABA and JA signaling during rice seed germination, shedding light on the molecular networks of ABA-JA synergistic interaction.

Beneficial properties of soil bacteria from Cannabis sativa L.: Seed germination, phosphorus solubilization and mycelial growth inhibition of Fusarium sp.

Soil microbes play a vital role in promoting plant growth and health through various mechanisms, including nutrient availability, microbial competition inhibition, and plant defense. However, their interaction and effects in cannabis cultivation remains largely unexplored. In this study, we investigated the symbiotic effects of soil bacteria on cannabis by characterizing microbial communities from soil samples collected in the Salado-Ibague (S) and Mariquita (M) regions of central west Colombia. Among the 265 microorganisms detected, we selected 21 g-positive bacteria from S and 10 g-positive bacteria from M for further analysis. The cannabis seed germination rates were evaluated after eight months of storage and seed pretreatment to assess the potential benefits of these soil bacteria. Remarkably, seed germination rates exceeding 80% were exhibited by 10 Bacilli strains, highlighting their ability to maintain germination potential even under storage and pretreatment conditions. In addition, antagonism assays were conducted to investigate the inhibitory effects of Bacilli on the mycelial growth of the pathogen Fusarium oxysporum (MGIF). Significant inhibition of mycelial growth was observed in nine Bacillus strains. Among them, Bacillus S11 exhibited the most significant inhibition (MGIF: 65%) compared to the control F. oxysporum (MGIF: 0%) (n = 3, p < 0.05). Additionally, the phosphorus solubilization capacity of cannabis soil Bacilli was examined using the phosphorus solubilization index (PSI). Among 31 Bacilli evaluated, six significantly increased the bioavailability of non-useable tricalcium phosphate into a useable form of monophosphate (PSI: 247–435). Our study has unveiled several beneficial characteristics of Bacillus strains isolated from cannabis soil. These include maintaining seed germination rates even after extended storage and pretreatment, exhibiting phosphorus solubilization capabilities, and demonstrating inhibitory effects against the microbial pathogen F. oxysporum. These findings emphasize the potential of harnessing the beneficial properties of Bacilli for sustainable cannabis cultivation practices.

Determining the Median Lethal Concentration (LC50) and Seedling Growth Effects of MARDI Nano-fertilizer on Rock melon (Cucumis melo)

New fertilizer formulations and nitrogen delivery systems are needed to address deteriorating nutrient-use-efficiency and environmental hazards due to farmers' dependency on chemical fertilizers. Nanofertilizers (NF) made from tailored smart nano materials are a viable alternative to inefficient and harmful traditional fertilizers. Nanotechnology and NFs may help solve chemical fertilizers formulation difficulties. To boost rock melon yields, MARDI has created a nano-fertilizer made from nano-emulsions. The relations between seed germination inhibition (%) of rock melon seed and different concentrations of MARDI nano-fertilizer showed that when nano-fertilizer concentrations increased from 10 to 45% with inhibition 3.3% to 100%, seed germination decreased. The LC50 value was calculated at 32.2% equal to 322,000 ppm, with upper and lower limits at 25.346% and 40.953%, 96 hrs after treatments, indicating the formulation is not toxic with a high LC50 value. In order to further study the effects of the created nano-fertilizer on the growth of rock melon plants across the adult, reproductive, and developmental stages, it is suggested that future field trials work use a concentration of 0.5% of the developed MARDI nano-fertilizer.

Review of the Current Research Progress of Seed Germination Inhibitors

Germination inhibitors, which inhibit the germination of seeds, spores and other plant reproductive material, are abundant in the plant kingdom and include phenols, cyanides, alkaloids, essential oils, amino acids, etc. These inhibitors can be classified as germination destructors and germination retarders depending on whether they harm the morphology, structure and physiology of the seed. Germination retarders are closely related to seed dormancy, and exogenous retarders can be used to extend the “dormancy” period of non-dormant seeds or perishable seeds by applying the proper dosage. They have significant potential applications as preservatives for seed preservation following harvest or for the storage of long-term germplasm resources. Germination destructors, as a type of relatively high-efficiency, low-specificity “toxic chemicals”, are of significant benefit in the application of effective and environmentally benign herbicides. At present, the main problems related to the research methods of germination inhibitors include difficulty in determining the specific endogenous substances and the minimum inhibitory concentration to induce dormancy, as well as whether the application of exogenous inhibitors will cause physiological damage to seeds. In the future, we should strengthen the tracking of germination inhibitors, explore the mechanisms of action of specific substances and deeper molecular mechanisms and finally explore new developments and new applications of different inhibitors.

Comparative chemical composition and pesticidal evaluation of Acorus calamus accessions collected from different geographical locations

The objectives of the present study were to investigate the phytochemical composition of essential oils (EO) from rhizomes of Acorus calamus collected from Jorhat, Assam; Munsyari and Pantnagar, Uttarakhand, India. EOs were studied for different pesticidal activities viz; nematicidal, insecticidal, and herbicidal activity. To study the synergistic effect of EOs on pesticidal activity, four combinations of EOs were prepared. Phenylpropanoids with β-asarone as the main compound were identified in all collections with varying percentages. Its contribution was found to be 85.8% in Munsyari EOs followed by 74.3% in Pantnagar and 62.6% in Assam collections. All EOs exhibited dose-dependent in vitro nematicidal activity against Meloidogyne incognita in terms of immobility and inhibition of egg hatching. The activity was observed as maximum in the EO combination of all three collections (1:1:1) whereas minimum in the Assam collections. In insecticidal activity against Lipaphis erysimi and Selepa celtis, maximum mortality was observed in Munsyari collections. The oils were assessed for sprout inhibition activity in terms of seed germination inhibition, coleoptile growth of the shoot and root against Raphanus raphanistrum. Maximum seed germination inhibition, % shoot, and root growth inhibition were found in all collections EO combinations. To predict the possible mode of action and the structure-activity relationship between major compounds of EOs and biological activities, in silico molecular docking and ADME/Tox studies were performed. The docking results revealed the mode of action of proteins of insects, nematodes, and weeds and were found in support of in vitro experiments. The study may be helpful for the development of herbal-based pesticides after proper clinical trials.

Evaluation of Helichrysum arenarium flower exudate as an inhibitor on Lolium perrene seed germination under laboratory conditions

Abstract Compounds accumulated on the surface of plant tissues and structures like glandular trichomes and thin epicuticular layer are defined as exudate, external, superficial. They exhibited important protective activities - antifungal, antibacterial, insect antifeedant, larvicidal, antiplasmodial, and UV protective. The exudate obtained from Helichrysum arenarium flowers was evaluated for its inhibitory activity on germination and initial radicle elongation of Lollium perrene seeds. The experiment was done in vitro in Petri dishes. The exudate, in water–acetone mixture (99.5:0.5), was assayed at concentrations of 1, 3, 5, 7, and 10 mg/mL. The chemical composition of the exudate was analyzed by GC/MS. Exudate solution with 5 mg/mL concentration was found to cause more than 90% of seed germination inhibition. At the same concentration, complete inhibition of root growth was observed. The main bioactive component of exudate was identified as flavonoid aglycone–naringenin. The inhibitory activity of H. arenarium on seed germination was investigated for the first time in the present study.

Gibberellic Acid Alleviates Cadmium-Induced Seed Germination Inhibition through Modulation of Carbohydrate Metabolism and Antioxidant Capacity in Mung Bean Seedlings

Gibberellins (GA) are the decisive players in seed germination whose functionality could be adversely affected by the presence of cadmium (Cd); however, the underlying mechanisms are unclear. Eco-toxicological effects of Cd (0, 25, 50, 75, and 100 µM) on the early stages of ontogenesis in a mung bean variety (ML-2056) were investigated. Seed germination characteristics along with Cd-tolerance index were recorded at the seventh day of germination. Additionally, endogenous gibberellic acid (GA3) level, amylase activity, oxidative stress, and the antioxidant defense system were also investigated in Cd-stressed germinating seedlings. Results revealed that Cd reduced seed germination and interfered with GA synthesis in a concentration-dependent manner. Further, to validate the role of GA in Cd-tolerance, experiments were executed to explore the effect of seed priming with GA3 and its biosynthesis inhibitor paclobutrazol (PBZ) on ML-2056 under Cd stress. Application of GA3 improved the activities of amylase and carbohydrate-metabolizing enzymes, the antioxidant defense system, and sustained lower H2O2 and TBARS contents, whereas PBZ caused a significant reduction in growth and decreased endogenous GA3 content in Cd-stressed ML-2056, suggesting a crucial role of GA synthesis in reversing Cd-induced negative effects. Overall, GA synthesis played a crucial role in mitigating Cd toxicity in mung bean, which might be used as a criterion for developing Cd-stress-tolerant genotypes.

Phytochemical Screening and Evaluation of Pesticidal Efficacy in the Oleoresins of Globba sessiliflora Sims and In Silico Study.

Globba sessiliflora Sims is an aromatic rhizomatous herb of family Zingiberaceae which is endemic to Peninsular India. This study first reports the phytochemical profile and pesticidal potential of oleoresins obtained from the aerial and rhizome parts of Globba sessiliflora Sims. The oleoresins were prepared by the cold percolation method and were analyzed by a gas chromatography-mass spectrometry (GC-MS) method. Both the oleoresins varied greatly in composition, the major compounds identified in aerial part oleoresin (GSAO) were methyl linoleate, methyl palmitate, and phytol, while the major compounds present in rhizome part oleoresin (GSRO) were γ-sitosterol, 8 (17),12-labdadiene-15, 16-dial, methyl linoleate, and methyl palmitate. In order to evaluate the biological activities, the oleoresins were tested under laboratory conditions for nematicidal action and inhibition of egg hatching potential against root knot nematode, where GSRO was more effective. Insecticidal activity was performed against mustard aphid, Lipaphis erysimi and castor hairy caterpillar, Selepa celtis. In case of mustard aphid, GSRO (LC50 = 154.8 ppm) was more effective than GSAO (LC50 = 263.0 ppm), while GSAO (LC50 = 346.7.0 ppm) was more effective against castor hairy caterpillar than GSRO (LC50 = 398.1 ppm). The herbicidal activity was performed in the receptor species Raphanus raphanistrum subsp. sativus, and the oleoresins showed different intensities for seed germination inhibition and coleoptile and radical length inhibition. Molecular docking studies were conducted to screen the in vitro activities and through molecular docking, it was found that the major oleoresins components were able to interact with the binding pocket of HPPD and AChE with γ-sitosterol showing the best binding affinity.

Comparison of Pregnant Diagnosis in Local Buffalo with a Seed Germination Inhibition Test and Rectal Palpation

Comparison of Pregnant Diagnosis in Local Buffalo with a Seed Germination Inhibition Test and Rectal Palpation

Optimal conditions for the high yield of bioactive asterric acid from marine derived Fungus Aspergillus sp.

Marine-derived microorganisms are vital sources of bioactive secondary metabolites. Secondary metabolites of coral-derived fungi have several essential bioactivities. Asterric acid 1 is a broad-spectrum bioactive secondary metabolite of several fungal genera, especially Aspergillus and Penicillium. It has a wide range of interesting bioactivities such as antifungal, antimicrobial, cytotoxic, fungicidal, pesticidal, nematicidal, seed germination inhibition, anti-HIV activity, as a first non-peptide for endothelin binding inhibition, anti-plasmodial activity against the erythrocyte stages of chloroquine-resistant Plasmodium falciparum, having vascular endothelial growth factor inhibitory activity and as medicine for the initial stage of an endothelin receptor agonist. In this study, the yield of asterric acid was improved to a multi-gram quantity from the soft coral-derived fungus Aspergillus sp. through media optimization. The pure spoors of Aspergillus sp. were fermented at room temperature in the absence of sodium chloride salt. The yield of asterric acid was 650 mg/L at optimal conditions. The optimal conditions for the high yield of asterric acid were found as rice medium, room temperature, 56 days incubation and absence of sodium chloride salt.

The potential of seed germination inhibition test for early pregnancy detection and improved reproductive efficiency of cattle in Zambia

Early pregnancy diagnosis is an important management practice for reducing calving interval, increasing cattle reproductive efficiency, and the overall herd productivity. This study was undertaken to assess the viability of seed germination inhibition technique (Punyakoti test) for early pregnancy detection in cattle under the tropical rearing conditions. Twenty-four randomly selected cows were used for the experiment. Urine samples were collected and subjected to Punyakoti test, using maize seeds, within 6 hours of collection. Descriptive statistics employing means and standard error were used to analyse data, also, inferential statistics including analysis of variance and t-tests were employed to ascertain differences between the variables under study. Urine from pregnant cows had the highest (80.03±3.99) inhibitory effect while the distilled water group had the least (7.50±3.81) mean seed germination inhibition. The means of germinated maize seeds in pregnant and non-pregnant cow urine treatment groups were significantly different. The means of germinated maize seeds in unstripped and stripped pregnant cow urine were significantly different, while the mean shoot length values for the same treatments were not significantly different. Urine from 42 days’ pregnant cows had the highest germination inhibition (80.21±3.59) while the least (25.00±4.35) was observed on day 10. The Punyakoti test reliably detected pregnancy starting from 26 days after insemination. In conclusion, this technique can be used for detecting pregnancy as early 26 days after insemination. The potential role of steroids and involvement of abscisic acid (ABA) in seed germination inhibition requires further investigation.

Evaluation of phytotoxicity of sweet cheese whey in alfalfa and corn

The use of cheese whey in agricultural applications is an option to reduce the environmental impact caused when it is dumped without control. The purpose of this work was to measure the phytotoxicity of the sweet whey that is generated during the production of fresh cheese using seeds and seedlings of alfalfa (Medicago sativa L.) and corn (Zea mays L.) as test-object organisms. The variables evaluated were the lethal concentration (LC50) due to the inhibition of germination in both seeds, and the sublethal concentration (CSL) due to the decrease in the development of sprouts and seedlings. Four individual experiments were carried out under controlled laboratory conditions, both in Petri dishes with culture medium and in germinators with support, in a completely randomized experimental design (DECA) with five treatments (4, 8, 12, 16 and 20% of whey and a drinking water control) with a total of 252 experimental units. The results obtained indicate that sweet whey has an LC50-5 of 53% and a CSL-10 of 12% in alfalfa seeds (p&lt;0.05) and an LC50-60 of 20% in alfalfa seedlings and an LC50-20 of 20% in corn seedlings. It was observed at 60 days that at concentrations between 4 and 6%, sweet whey has a growth-promoting effect on corn seedlings (p&lt;0.05), concluding that it is possible to safely use diluted whey in sustainable agricultural practices.

ABA-insensitivity of alfalfa (Medicago sativa L.) during seed germination associated with plant drought tolerance

Abscisic acid (ABA) is a vital stress hormone of plants in coping with adverse environmental conditions, such as drought stress. Sensitivity of seed germination to exogenous ABA treatment could be linked to varied drought stress responses in different plant species. Polyploid and outcrossing nature of alfalfa makes it an extensive reservoir of genetic variation, and each single alfalfa seed may have a different genetic background. We speculate the alfalfa seeds resistant to exogenous ABA treatment during germination could lead to a strong plant drought tolerance. Here, we selected the alfalfa seedlings (S0–50) from seeds germinated under 50 μM ABA treatment. The S0–50 alfalfa plants showed more sensitivity in stomatal closure to exogenous ABA and PEG treatments, and also stronger drought tolerance than the plants of ABA-sensitive seeds during germination (S0–0). Leaf ABA content analysis indicated that the S0–50 plants had a higher ABA content in normal and under drought stress growth conditions than the S0–0 plants. The seeds of the S0–50 plants (S1–50) showed significantly higher germination percentage under 50 μM ABA treatment and had longer roots after 15% PEG6000 treatment than the segregated ABA-sensitive seeds (S1–0). We found a cytosol-nucleus dual-localized PPR protein gene MsSOAR1 was significantly highly expressed in the S0–50 than in the S0–0 plants. Overexpression of AtSOAR1 , a negative regulator in ABA-mediated seed germination inhibition in Arabidopsis and a homologous gene of MsSOAR1 , led to significantly improved drought tolerance, increased branch number and plant height, and reduced expression of the ABA receptor genes MsPYL5 and MsPYL6 of AtSOAR1 transgenic alfalfa plants (TGs) . The results suggest that ABA-insensitivity during seed germination is associated with the impaired ABA signaling transduction. Screening alfalfa seedlings during seed germination with exogenous ABA is a way to obtain drought tolerant alfalfa germplasm. • During vegetative stage, the ABA-insensitive ‘Zhongmu No.1’ alfalfa plants, during seeds germination, showed stronger drought tolerance. • Higher ABA content and higher expression of MsSOAR1 gene may contributed to improved drought tolerance of alfalfa plants. • Ectopic overexpression of AtSOAR1 significantly improved alfalfa drought tolerance. • Screening alfalfa seedlings during seed germination with exogenous ABA is a way to obtain drought tolerant alfalfa germplasm.

Phytochemical Profile, In Vitro Bioactivity Evaluation, In Silico Molecular Docking and ADMET Study of Essential Oils of Three Vitex Species Grown in Tarai Region of Uttarakhand.

A comparative study of volatiles, antioxidant activity, phytotoxic activity, as well as in silico molecular docking and ADMET study, was conducted for essential oils from three Vitex species, viz., V. agnus-castus, V. negundo, and V. trifolia. Essential oils (OEs) extracted by hydrodistillation were subjected to compositional analysis using GC-MS. A total number of 37, 45, and 43 components were identified in V. agnus-castus, V. negundo, and V. trifolia, respectively. The antioxidant activity of EOs, assessed using different radical-scavenging (DPPH, H2O2 and NO), reducing power, and metal chelating assays, were found to be significant as compared with those of the standards. The phytotoxic potential of the EOs was performed in the receptor species Raphanus raphanistrum (wild radish) and the EOs showed different levels of intensity of seed germination inhibition and root and shoot length inhibition. The molecular docking study was conducted to screen the antioxidant and phytotoxic activity of the major and potent compounds against human protein target, peroxiredoxin 5, and 4-hydroxyphenylpyruvate dioxygenase protein (HPPD). Results showed good binding affinities and attributed the strongest inhibitory activity to 13-epi-manoyl oxide for both the target proteins.

Effects of Chitosan and Silica Nanoparticles Against the Development and Growth of Red Chilli Anthracnose Disease Colletotrichum sp.

&lt;b&gt;Background and Objective:&lt;/b&gt; &lt;i&gt;Colletotrichum&lt;/i&gt; sp., is a pathogen that causes anthracnose disease that can reduce chilli production. One environmentally for controlling plant disease can be done using chitosan and silica nanotechnology. This study aimed to test the ability of chitosan and silica nanoparticles to inhibit the growth of &lt;i&gt;Colletotrichum&lt;/i&gt; sp. and suppress the development of the diseases on chilli seeds. &lt;b&gt;Materials and Methods:&lt;/b&gt; This research consisted of the pathogenicity test of chitosan and silica nanoparticles and chilli seed germination inhibition test to control the development of &lt;i&gt;Colletotrichum&lt;/i&gt; sp., using a completely randomized design within 10 treatments and 3 replications. &lt;b&gt;Results:&lt;/b&gt; The results showed that 100 ppm chitosan nanoparticles inhibited the growth of &lt;i&gt;Colletotrichum&lt;/i&gt; sp. and conidia germination with inhibition percentages of 92.20 and 99.4%, respectively. In addition, the development of anthracnose on chilli seed germination has been suppressed by 93% at a 100 ppm concentration of silica nanoparticles. &lt;b&gt;Conclusion:&lt;/b&gt; In conclusion, both single or mixed formulations of chitosan and silica nanoparticles were able to inhibit the growth and development of &lt;i&gt;Colletotrichum &lt;/i&gt;sp. and increase the chilli seed viability.

Phytotoxic Effect of Treated Wastewater on Seed Germination and Percent Root Elongation Inhibition in Some Vegetable Crops

Aims: Summer irrigations for citrus fruits and fodder are considered as pre-irrigations for growing annual crops in Tunisia. However, given the quality of this treated wastewater, pre-irrigation effect on the seed germination capacity remains unclear. We propose to study the effect of different concentrations of treated wastewater on the germination of some vegetables.&#x0D; Methodology: This laboratory experiment investigates the effect of different concentration from 0 to 100% (0%, 20%,40%, 60%, 80% and 100%) of treated wastewater on seed germination (%), germination index (Ig), root elongation and root elongation inhibition index (REI%) for some vegetable crops, the most commonly used by farmers: Radish, Okra and Pea.&#x0D; Results: Pea germination rate (%G) dropped significantly from 60% to 30% with WW concentration. The germination index (Ig) decreased for Radish and Pea seeds with increasing WW concentration; it decreases from 1.03 to 0.72 and from 0.8 to 0.33 for radish and pea, respectively. While, the sprouting index for okra increased from 1.24 to 2.2 with increasing WW concentration. According to the REI% values, there is no effect of WW concentration on the root elongation of okra. On the other hand, the most pronounced REI% was noticed for Pea which has shown positive REI% values for all the concentrations with an inhibition effect of about 67% for the 100% WW treatment. For the radish, the root elongation inhibition started from the 40% WW concentration.&#x0D; Conclusion: The crops tested have been arranged in the following order: Okra&gt;Radish&gt;Pea depending on the tolerance to treated wastewater. We conclude that the effect of treated wastewater on seed germination is depending on crops species and we should take care before using the treated wastewater for pre-sowing irrigation purposes.