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This study aimed at evaluating the effectiveness of chitosan nanoparticles (ChNPs), silver nanoparticles (AgNPs) and their combination (Ch-AgNPs) in controlling the chocolate spot of faba bean caused by Botrytis fabae. Five isolates of B. fabae were collected from diseased faba bean plants and screened for pathogenicity on the most susceptible faba bean cultivar, Giza 843. Among the isolates, B. fabae isolate No.3 exhibited the highest virulence. Antifungal effects of ChNPs, AgNPs (with an average particle size of 15 and 42 nm, respectively), and Ch-AgNPs mixture at 5, 10 and 20 ppm were assessed against B. fabae isolate No.3. In vitro experiments demonstrated that the Ch-AgNPs mixture at 20 ppm exhibited the greatest inhibitory effect on the mycelial growth of B. fabae, with a reduction of 100% compared to the individual nanoparticles. Transmission electron microscopy revealed notable cellular changes in B. fabae cells treated with the Ch-AgNPs mixture. Greenhouse results exhibited that the great reductions in disease severity were achieved with Tridex 80% WP® fungicide (96.51%), followed by Ch-AgNPs mixture with 84.53% reduction. The Ch-AgNPs mixture effectively enhanced the activity of peroxidase and polyphenoloxidase enzymes and the total phenol content in the plants. Application of ChNPs, AgNPs, and the Ch-AgNPs mixture significantly improved faba bean growth and yield parameters. However, the cytotoxicity assay indicated a concentration-dependent toxic effect of Ch-AgNPs, with no significant hemolytic activity observed in red blood cells. In conclusion, the Ch-AgNPs mixture was promising as a fungicide for combating the chocolate spot in faba bean.

Incorporating the Internet of Things (IoT) and smart irrigation systems into developing regions encounters significant financial constraints. To address this gap, this study aimed to identify the most effective locations for the sensor deployment using the Geographic Information System (GIS) techniques, maximizing the spatial coverage of soil moisture states while minimizing the number of required wireless sensor nodes. Ensuring the accuracy of YL-69 soil moisture sensors is pivotal for system efficiency therefore, a volumetric water content (VWC) calibration was conducted. Soil samples from the surface and subsurface layers were subjected to a comprehensive laboratory analysis to assess their physical and chemical attributes. Employing the Soil-Plant-Atmosphere-Water model (SPAW), the available water-holding capacity (AWHC) for these soil samples was estimated. A sensor placement strategy was formulated, aligning with AWHC maps to detect the spatial variations at varying depths. Further soil samples were collected to fine-tune the sensor calibration. Our findings revealed that third-order polynomial regression equations yielded the best correspondence between the sensor readings and the reference VWC measurements, with R2 values ranged from 0.94 to 0.99 for surface layers and 0.95 to 0.98 for subsurface layers. This innovative approach facilitated the deployment of IoT and smart irrigation applications by determining the optimal sensor placement and enhancing the efficiency and cost-effectiveness of the water management systems.

AbstractThis study addressed the increasing challenges of climate change by exploring the use of machine learning (ML) algorithms to predict the reference evapotranspiration (ETo). Accurate ETo prediction is crucial for optimizing irrigation water management. This research aimed to assess the reliability and accuracy of ML algorithms in predicting ETo values. Three ETo calculation methods were employed: Penman-Monteith (PM), Hargreaves (HA), and Blaney-Criddle (BC). The study analyzed ETo and other climate variables using the modified Mann-Kendall test (m-MK) and Theil Sen’s slope estimator methods to identify trends. Multiple ML algorithms, including Support Vector Regression (SVR), Random Forest (RF), XGboost, K-Nearest Neighbor (KNN), Decision Trees (DT), Linear Regression (LR), and Multiple Linear Regression (MLR) were utilized for ETo prediction. The ML algorithms exhibited excellent performance, with coefficients of determination (R2) values ranging from 0.97 to 0.99 for PM, 0.99 for HA, and from 0.91 to 0.92 for BC. The models demonstrated a high value of the Kling-Gupta efficiency (KGE) with low Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) values. Strong correlations between the predicted and calculated daily ETo were observed with R2 values of 0.99, 0.99, and 0.92 for PM, HA, and BC methods, respectively. In conclusion, this study affirmed the accuracy and reliability of ML algorithms to match that of standard ETo prediction equations.

Abstract Calcareous soils are characterized by a high calcium carbonate content (calcite), which plays a crucial role in the soil structure, plant growth, and nutrient availability. The high content of CaCO3 leads to the increment of the soil alkalinity, which results in a lowering of the nutrient availability causing a challenge for the agriculture in these soils. In this study, the calcite-solubilizing potential of the diazotrophic Azotobacter salinestris YRNF3 was investigated in vitro as a probable bio-agent for enhancing the calcareous soils properties such as soil pH and nutrient availability. Twelve diazotrophic bacterial strains were isolated from wheat rhizosphere collected from different wheat-cultivated fields in five Egyptian governorates. Using Nessler’s reagent, all isolated bacterial strains were found to have the ability to produce ammonia. By amplification of nifH gene, a PCR product of 450 bp was obtained for all isolated bacterial strains. For each isolate, three biological and three technical replicates were applied. All isolated diazotrophic bacteria were qualitatively screened for their calcite-solubilizing ability. To quantitatively investigate the calcite-solubilizing potential of A. salinestris YRNF3 in vitro, changes in the contents of soluble calcium (Ca2+), bicarbonate (HCO3 −), total nitrogen (TN), total protein (TP), and pH were daily measured in its culture filtrate along 10 days of incubation. The results showed that the pH values in the culture filtrate ranged from 5.73 to 7.32. Concentration of Ca2+ and HCO3 − in the culture filtrate significantly decreased with the increment in the incubation time, while concentration of TN increased along the time. The highest TN concentration (0.0807 gL−1) was observed on days 4 and 5, compared to that of the day 0 (0.0014 gL−1). Content of TP in the culture filtrate also significantly increased along the incubation period. The highest TP content was recorded in day 4 (0.0505%), while no TP content was recorded on day 0. Furthermore, data obtained revealed that A. salinestris YRNF3 produced acid phosphatase at low activity (5.4 U mL−1). HPLC analysis of the culture filtrate indicated production of different organic acids, namely lactic acid (82.57 mg mL−1), formic acid (46.8 mg mL−1), while acetic acid was detected in a low quantity (3.11 mg mL−1). For each analysis, three replicates of each treatment were analyzed. Means of the tested treatments were compared using Tukey's HSD test at p ≤ 0.05. In conclusion, findings of this work suggested that A. salinestris YRNF3 has the potential to be a probable bioagent to be used for the reclamation of the calcareous soils by solubilizing CaCO3, improving soil fertility, and promoting plant growth. However, further studies are needed to investigate its field application and their long-term effects on the soil properties and plant productivity. To the best of the author's knowledge, this is the first study reporting the calcite-solubilizing ability of a nitrogen-fixing bacteria. Having these two abilities by one microorganism is a unique feature, which qualifies it as a promising bioagent for reclamation of the calcareous soils.

Abstract Environmental pollution due to the improper use of the chemical fungicides represents a vital ecological problem, which affects human and animal health, as well as the microbial biodiversity and abundance in the soil. In this study, an endophytic fungus Aspergillus oryzae YRA3, isolated from the wild plant Atractylis carduus (Forssk.) C.Chr, was tested for its biocontrol activity against Rhizoctonia root rot of sorghum. The antagonistic potential of A. oryzae YRA3 was tested against Rhizoctonia solani in vitro. A full inhibition in the growth of R. solani was recorded indicating a strong antagonistic potential for this endophyte. To investigate the chemical composition of its metabolites, GC/MS analysis was used and thirty-two compounds in its culture filtrate were identified. Among these metabolites, some compounds with an antifungal background were detected including palmitic acid, 2-heptanone, and 2,3-butanediol. To these antifungal metabolites the antagonistic activity of A. oryzae YRA3 can be attributed. In the greenhouse experiment, treating of the infected sorghum plants with A. oryzae YRA3 significantly reduced severity of the Rhizoctonia root rot by 73.4%. An upregulation of the defensive genes (JERF3), (POD) and (CHI II) was recorded in sorghum roots when were inoculated with A. oryzae YRA3. In addition, an increment in the activity of peroxidase and polyphenol oxidase, as well as the total phenolic content in the sorghum roots was also recorded. Furthermore, the results obtained from the greenhouse experiment revealed a growth-promoting effect for inoculating the sorghum plants with A. oryzae YRA3. It can be concluded that A. oryzae YRA3 can be a probable biological agent to control this disease in sorghum. However, its evaluation under field conditions is highly needed in the future studies.

Fusarium head blight (FHB) is a devastating fungal disease caused by Fusarium graminearum. Pectin lyase, a pectinase, acts on the α-1,4-glycosidic linkage of galacturonic acid primarily by β-elimination. In this study, three pectin lyase genes (FgPel1, 2, 3) in F. graminearum were selected, and deletion mutants (ΔFgPel1, 2, 3) were constructed by homologous recombination for functional characterization. The gene deletions affected the morphology and growth rate of F. graminearum on pectin medium at various concentrations, with the growth rate of ΔFgPel1 being more significant. The growth of ΔFgPel1 colonies slowed at pH 4, with optimal growth at pH 6.5, whereas ΔFgPel2 and ΔFgPel3 exhibited greater inhibition at pH 8. Colony morphology and diameter of the deletion mutants showed no significant differences compared to the wild-type strain PH-1, and there was no effect on conidial production or germination rate. Pathogenicity assays demonstrated that gene deletion significantly reduced the ability of F. graminearum to infest corn silks and wheat ears, and that ΔFgPel2 showed a more pronounced reduction in pathogenicity on wheat spikes. In summary, the pectin lyase genes (FgPel1, 2, 3) are involved in pectin utilization and are influenced by external pH conditions, which attenuate the pathogenicity of F. graminearum without affecting its vegetative growth or asexual spore formation. These findings elucidate the roles of these genes and provide a basis for controlling FHB.

Abstract Background Stripe rust is considered one of the most devastating diseases of wheat all over the world, resulting in a high loss in its production. In this study, time-course changes in expression of the polyphenol biosynthesis pathways genes in wheat against stripe rust were investigated. The defense mechanisms triggered by mycorrhizal colonization and/or spraying with Streptomyces viridosporus HH1 against this disease were also investigated. Results Results obtained revealed that C3H, which is considered the key gene in lignin biosynthesis, was the most expressed gene. Furthermore, most of the chlorogenic acid and flavonoid biosynthesis genes were also overexpressed. Volcano plots of the studied genes reveal that the dual treatment led to a high significant overexpression of 10 out of the 13 studied genes. Heatmap of these genes showed that the most frequent expressed gene in response to all applied treatments along the study period was DFR, the key gene in the biosynthesis of anthocyanidins. Gene co-expression network of the studied genes showed that HQT was the most central gene with respect to the other genes, followed by AN2 and DFR, respectively. Accumulation of different flavonoids and phenolic acids were detected in response to the dual treatment, in particular, cinnamic acid, coumarin, and esculetin, which recorded the highest elevation level recording 1000, 488.23, and 329.5% respectively. Furthermore, results from the greenhouse experiment showed that application of the dual treatment led to an 82.8% reduction in the disease severity, compared with the control treatment. Conclusions We can conclude that the biosynthesis of lignin, chlorogenic acid, and flavonoids contributed to the synergistic triggering effect of the dual treatment on wheat resistance to stripe rust.

This research evaluated the importance of establishing an integrated sprinkler irrigation design connected to fish farm ponds in order to achieve environmental and financial benefits. To achieve the aim of the study, two field experiments were conducted at a private farm in the Nubaria area of Beheira Governorate during the 2022 and 2023 seasons to quantify all the benefits from using fish water effluent (FWE) in irrigation. The obtained results indicated that the effluent could represent a good source of irrigation and bio-fertilization. The yield of tomato was higher when using FWE for irrigation compared with using groundwater for irrigation (IW). This was due to the additional amounts of dissolved bio-nitrogen along with other nutrients present in the FWE. The proportion of dissolved nitrogen added by using FWE was 22.3 kg nitrogen per hectare in 2022 and 24.6 kg nitrogen per hectare in 2023, in addition to some other major elements such as phosphorus and potassium, which are also among the main nutrients needed by crops. It has also been noticed that the fertility of the sandy soil increased with the use of FWE for irrigation. One of the most important results was the possibility of reducing the addition of nitrogen mineral fertilizers by 25%, thus saving on N fertilizers when growing tomato. In addition to the vitality of the FWE and its macro- and microelements, algae, microorganisms, and other organic materials, the use of this type of water as an alternative source for irrigation, along with the reduction in the amount of added mineral fertilizers, will reduce the degree of groundwater contamination with mineral fertilizers and increase the income of farmers. It was also observed that the air temperature decreased during the growing season when compared with the temperature of uncultivated surrounding areas.

Abstract Fusarium root rot, caused by Fusarium solani (Mart.) Sacc., represents one of the most damaging diseases of maize affecting plant growth and yield. In this study, the antagonistic potential of a non-aflatoxigenic endophytic Aspergillus flavus YRB2, isolated from Thymelaea hirsuta (L.) Endl., was tested against F. solani in vitro. In addition, its biocontrol activity against Fusarium root rot of maize was evaluated under greenhouse conditions. Its impacts on plant molecular, pathological, physiological, and growth levels were also studied. Results obtained revealed a potent antagonistic behavior for A. flavus YRB2 against F. solani in vitro, recording 80% growth inhibition. Seventeen secondary metabolites were detected in the n-hexane extract of A. flavus YRB2 filtered culture broth using GC-MS analysis. Among them, various antifungal secondary metabolites were produced, namely palmitic acid, α-linolenic acid, stearic acid, 2, 4-di-tert-butylphenol, diisobutyl phthalate, and heneicosane. In contrast, HPLC analysis showed that no aflatoxins (B1, B2, G1, and G2) were detected. Under greenhouse conditions, colonization of maize plants with A. flavus YRB2 exhibited a potential biocontrol activity against Fusarium root rot, recording 73.4% reduction in the disease severity. Triggering of transcriptional expression level of the defense-related genes JERF3 (7.2-fold), CHI II (8-fold), and POD (9.1-fold) was reported, indicating the inducing effect on the plant immunity. In addition, an increment in the antioxidant enzymes POD and PPO, and the total phenolic content in maize roots was also observed in response to this treatment. Moreover, a growth-promoting effect was also observed for colonization of maize plants with A. flavus YRB2. Based on the obtained data, we can conclude that A. flavus YRB2 may represent a promising biocontrol and growth-promoting agent for maize plants against Fusarium root rot. Nevertheless, field evaluation is highly requested before the use recommendation.

Abstract Sorghum damping-off, caused by Fusarium solani (Mart.) Sacc., is a serious disease which causes economic loss in sorghum production. In this study, antagonistic activity of lavender essential oil (EO) at 0.5, 0.75, 1.0, 1.25, 1.5, and 1.6% against F. solani was studied in vitro. Their effects on regulation of three SbWRKY transcription factors, the response factor JERF3 and eight defense-related genes, which mediate different signaling pathways, in sorghum were investigated. Effects of application under greenhouse conditions were also evaluated. The results showed that lavender EO possesses potent antifungal activity against F. solani. A complete inhibition in the fungal growth was recorded for lavender EO at 1.6%. Gas chromatography–mass spectrometric analysis revealed that EO antifungal activity is most likely attributed to linalyl anthranilate, α-terpineol, eucalyptol, α-Pinene, and limonene. Observations using transmission electron microscopy revealed many abnormalities in the ultrastructures of the fungal mycelium as a response to treating with lavender EO, indicating that multi-mechanisms contributed to their antagonistic behavior. Results obtained from Real-time PCR investigations demonstrated that the genes studied were overexpressed, to varying extents in response to lavender EO. However, SbWRKY1 was the highest differentially expressed gene followed by JERF3, which suggest they play primary role(s) in synchronously organizing the transcription-regulatory-networks enhancing the plant resistance. Under greenhouse conditions, treating of sorghum grains with lavender EO at 1.5% prior to infection significantly reduced disease severity. Moreover, the growth parameters evaluated, the activities of antioxidant enzymes, and total phenolic and flavonoid contents were all enhanced. In contrast, lipid peroxidation was highly reduced. Results obtained from this study support the possibility of using lavender EO for control of sorghum damping-off. However, field evaluation is highly needed prior to any usage recommendation.

Aflatoxin B1 is one of the most deleterious types of mycotoxins. The application of an endophytic fungus for biodegradation or biosuppression of AFB1 production by Aspergillus flavus was investigated. About 10 endophytic fungal species, isolated from healthy maize plants, were screened for their in vitro AFs-degrading activity using coumarin medium. The highest degradation potential was recorded for Trichoderma sp. (76.8%). This endophyte was identified using the rDNA-ITS sequence as Trichoderma harzianum AYM3 and assigned an accession no. of ON203053. It caused a 65% inhibition in the growth of A. flavus AYM2 in vitro. HPLC analysis revealed that T. harzianum AYM3 had a biodegradation potential against AFB1. Co-culturing of T. harazianum AYM3 and A. flavus AYM2 on maize grains led to a significant suppression (67%) in AFB1 production. GC-MS analysis identified two AFB1-suppressing compounds, acetic acid and n-propyl acetate. Investigating effect on the transcriptional expression of five AFB1 biosynthesis-related genes in A. flavus AYM2 revealed the downregulating effects of T. harzianum AYM3 metabolites on expression of aflP and aflS genes. Using HepaRG cell line, the cytotoxicity assay indicated that T. harazianum AYM3 metabolites were safe. Based on these results, it can be concluded that T. harzianum AYM3 may be used to suppress AFB1 production in maize grains.

Banana plants (Musa acuminata L.) are exposed to various biotic and abiotic stresses that affect their production worldwide. Banana plants respond to these stresses, but their responses to combined stresses are unique and differ from those to various individual stresses. This study reported the effects of the mycorrhizal colonization of banana roots and/or infection with root rot on the transcriptional expression of the responsive factor JERF3 and stress-responsive genes (POD, PR1, CHI, and GLU) under different salinity levels. Different transcriptional levels were recorded in response to the individual, dual, or triple treatments. All the applied biotic and abiotic stresses triggered the transcriptional expression of the tested genes when individually applied, but they showed different influences varying from synergistic to antagonistic when applied in combinations. The salinity stress had the strongest effect when applied in combination with the biotic stress and/or mycorrhizal colonization, especially at high concentrations. Moreover, the salinity level differentially affects the banana responses under combined stresses and/or mycorrhizal colonization in addition, the mycorrhizal colonization of banana plantlets improved their growth, photosynthesis, and nutrient uptake, as well as greatly alleviated the detrimental effects of salt and infection stresses. In general, the obtained results indicated that the responses of banana plantlets under the combined stresses are more complicated and differed from those under the individual stresses depending on the crosstalks between the signaling pathways.

Downy mildew is the most destructive disease of grapevines in the regions of relatively warm and humid climate causing up to 50% yield losses. Application of silicon- (Si-) based products have been extensively studied against various oomycete, fungal, bacterial, and viral plant diseases, but studies on Si application in their nanosize are limited. In this study, the field application of silica nanoparticles (SiNPs) on Thompson Seedless grapevines (H4 strain) infected with downy mildew was evaluated. In addition, molecular, physiological, ultrastructural, and toxicity investigations were also conducted. The obtained results revealed that spraying of grapevines with SiNPs at 150 ppm significantly overexpressed the transcription factor jasmonate and ethylene-responsive factor 3 recording 8.7-fold, and the defense-related genes β-1,3-glucanase (11-fold), peroxidase (10.7-fold) pathogenesis-related-protein 1 (10.6-fold), and chitinase (6.5-fold). Moreover, a reduction up to 81.5% in the disease severity was achieved in response to this treatment. Shoot length and yield per grapevine were considerably enhanced recording up to 26.3 and 23.7% increase, respectively. The berries quality was also improved. Furthermore, this treatment led to an enhancement in the photosynthetic pigments, induction of phenolic and ascorbic acid contents, an increase in the activity of peroxidase and polyphenol oxidase enzymes, and a reduction in the cellular electrolyte leakage, lipid peroxidation, and H2O2 content. Scanning electron microscopy observations showed an increase up to 86.6% in the number of closed stomata and a reduction up to 55% in the average stomatal pore area in response to this treatment. Observations of the transmission electron microscopy showed ultrastructural alterations in the cells of a grapevine leaf due to the infection with downy mildew, including plasmolysis and disruption of the cellular components, abnormal chloroplasts, and thickening of the cell wall and cell membrane. These abnormal alterations were reduced in response to SiNPs spray. In contrast, this study also showed that this treatment had considerable cytotoxic and genotoxic effects at this direct dose/concentration. So, additional investigations to determine the SiNPs residue in the produced edible plant parts are urgently needed. In addition, the pre-harvest interval, toxicity index, and risk assessment should be evaluated before any recommendation for use.

Studies of the biodiversity of plant pathogenic and toxigenic fungi are attracting great attention to improve the predictability of their epidemics and the development of their control programs. Two hundred maize grain samples were gathered from 25 maize-growing governorates in Egypt and 189 samples were processed for the isolation and identification of seed-borne fungal microbiome. Twenty-six fungal genera comprising 42 species were identified according to their morphological characteristics and ITS DNA sequence analysis. Occurrence and biodiversity indicators of these fungal species were calculated. Ustilago maydis, Alternaria alternata, Aspergillus flavus, A. niger, Penicillium spp., Cladosporium spp. and Fusarium verticillioides were the highly frequent (>90% for each), recording the highest relative abundance (˃50%). Al-Menia governorate showed the highest species diversity and richness, followed by Sohag, Al-Nobaria and New Valley governorates. Correlations of 18 fungal species with temperature, relative humidity, precipitation, wind speed, and solar radiation were analyzed using canonical correspondence analysis. Results showed that relative humidity, temperature, and wind speed, respectively, were the most impactful weather variables. However, the occurrence and distribution of these fungi were not clearly grouped into the distinctive climatic regions in which maize crops are grown. Monitoring the occurrence and distribution of the fungal pathogens of maize grains in Egypt will play an important role in predicting their outbreaks and developing appropriate future management strategies. The findings in this study may be useful to other maize-growing countries that have similar climatic conditions.

Rhizoctonia root rot is one of the most destructive diseases of tomato and other crops. The biocontrol of plant diseases using endophytic bacteria has gained significant attention due to their distinct advantages compared with the free-living ones, as well as their new unexplored and unique properties. Endophytic Bacillus subtilis SR22 represents a promising and more effective biocontrol and growth-promoting agent for tomato plants than the free-living agents, being an ecofriendly and sustainable tool in modern agriculture. In this study, the direct antagonistic activity of B. subtilis SR22 was investigated against Rhizoctonia solani in vitro. The biocontrol activity of B. subtilis SR22 against Rhizoctonia root rot of tomato was also investigated. Effects on the level of the transcriptional expression of defense-related genes, biochemical responses, and the vegetative growth of tomato plants were also studied. The dual culture test showed 51% inhibition in the mycelial growth of R. solani due to B. subtilis SR22, indicating its potent antagonistic behavior. Using a GC-MS analysis, twenty bioactive compounds were detected to be produced by B. subtilis SR22, including chlorogenic acid, pyrrolo [1,2-a]pyrazine-1,4-dione, hexahydro, propyl thioglycolic acid, phthalic acid, and 2,3-butanediol. Under greenhouse conditions, the application of B. subtilis SR22 led to a reduction (up to 51%) in Rhizoctonia root rot of tomato. Furthermore, an upregulation in the expression of the responsive factor JERF3 (10.9-fold) and the defense-related genes POD (9.1-fold) and PR1 (4.5-fold) in tomato plants was recorded due to the application of B. subtilis SR22. In addition, this treatment enhanced the total phenolic content (76.8%) and activity of the antioxidant enzymes POD (56%) and PPO (29.2%) in tomato roots, indicating its resistance-inducing effect on tomato plants. Moreover, this treatment enhanced most of the evaluated growth parameters in tomato plants (up to 35%). We can conclude that B. subtilis SR22 is a promising biocontrol agent and growth promoter in tomato plants against Rhizoctonia root rot. An evaluation of the formulation and field application of this bio-agent is necessary in future studies.

Fusarium wilt is a detrimental disease of pea crop, resulting in severe damage and a reduction in its yield. Developing synergistically enhanced bioagents for disease management and growth promotion is pivotal for food safety, security, and sustainability. In this study, biocontrol potential of treating pea plants with Streptomycesviridosporus HH1 and/or their colonization with Rhizophagusirregularis against infection with Fusarium wilt was investigated. Impacts on the expression profiles of defense-related genes, biochemical, and ultrastructural levels, as well as the growth and yield of pea plants in response to these treatments, were also investigated. Data obtained indicated the antifungal activity of S. viridosporus HH1 against F. oxysporum f.sp. pisi in vitro. Furthermore, the GC-MS analysis revealed production of different bioactive compounds by S. viridosporus HH1, including 2,3-butanediol, thioglycolic acid, and phthalic acid. The results from the greenhouse experiment exhibited a synergistic biocontrol activity, resulting in a 77% reduction in disease severity in pea plants treated with S. viridosporus HH1 and colonized with R. irregularis. In this regard, this dual treatment overexpressed the responsive factor JERF3 (5.6-fold) and the defense-related genes β-1,3-glucanase (8.2-fold) and the pathogenesis-related protein 1 (14.5-fold), enhanced the total phenolic content (99.5%), induced the antioxidant activity of peroxidase (64.3%) and polyphenol oxidase (31.6%) enzymes in pea plants, reduced the antioxidant stress, and improved their hypersensitivity at the ultrastructural level in response to the Fusarium wilt pathogen. Moreover, a synergistic growth-promoting effect was also recorded in pea plants in response to this dual treatment. In this regard, due to this dual treatment, elevated levels of photosynthetic pigments and improved growth parameters were observed in pea leaves, leading to an increment in the yield (113%). In addition, application of S. viridosporus enhanced the colonization levels with R. irregularis in pea roots. Based on the obtained data, we can conclude that treating pea plants with S. viridosporus HH1 and colonization with R. irregularis have synergistic biocontrol activity and growth-promoting effects on pea plants against Fusarium wilt. Despite its eco-safety and effectiveness, a field evaluation of this treatment before a use recommendation is quite necessary.

Rhizoctonia root rot is one of the most destructive diseases affecting pea crops, resulting in up to 75% loss. In this study, the biocontrol activity of seaweed (Ascophyllum nodosum) extract at 1, 2, and 3% and/or mycorrhization of pea roots was investigated against Rhizoctonia root rot under greenhouse conditions. In addition, their effects on the transcriptional, physiological, ultrastructural, and growth status of pea plants were also studied. The results showed that the mycorrhizal colonization of pea roots and the application of the seaweed extract at 3% synergistically overexpressed the responsive factor (JERF3) recording 18.2-fold, and the defense-related genes peroxidase (23.2-fold) and chitinase II (31.8-fold). In addition, this treatment improved the activity of the antioxidant enzymes POD and PPO, increased the phenolic content in pea roots, and triggered multiple hypersensitivity reactions at the ultrastructural level of the cell, leading to a 73.1% reduction in disease severity. Moreover, a synergistic growth-promoting effect on pea plants was also observed. The photosynthetic pigments in pea leaves were enhanced in response to this dual treatment, which significantly improved their yield (24 g/plant). The inducing effect of mycorrhizal colonization on plant resistance and growth has been extensively studied. However, developing improved and synergistically acting biological agents for plant disease control and growth promotion as alternatives to the chemical fungicides is crucial for safety and food security. Based on these results, it can be concluded that the mycorrhizal colonization of pea roots and soaking their seeds in the A. nodosum extract at 3% have a promising and improved biocontrol activity against R. solani, and a growth-promoting effect on pea plants. However, field applications should be evaluated prior to any use recommendations.

White rot, caused by Sclerotium cepivorum, is a serious and economically important disease of garlic, which leads to losses in the garlic production in most of the tropical, subtropical and temperate areas. Biocontrol potential of an endophytic Bacillus amyloliquefaciens GGA and/or arbuscular mycorrhizal fungi (AMF) against this disease was investigated. The B. amyloliquefaciens GGA exhibited antagonistic activity against S. cepivorum in vitro. Scanning electron microscopy revealed alterations in the morphology of the pathogen in response to the exposure to the bacterial metabolites. Results from a pot experiment demonstrated that application of the dual treatment of the B. amyloliquefaciens GGA and AMF reduced disease incidence and severity more than the single treatments, and led to the greatest increases in total phenol content, activities of the defense-related enzymes phenylalanine ammonia-lyase, polyphenoloxidase and peroxidase, and transcriptional expression levels of the defensin and chitinase genes. Growth and yield parameters of garlic plants were enhanced after this treatment. This study showed good efficacy on the tested biocontrol agents for control white rot of garlic plants grown in pots. Future research should evaluate these biocontrol strategies under field conditions.

Fresh date palm fruits (cv. Barhi) have received much attention due to their sweet taste and popularity in marketing. There is a critical need to prolong their storability, as well as maintain their quality during the postharvest and marketing periods. In this study, the effects of spraying date palm trees with melatonin (Mt) and/or methyl jasmonate (Mj) at 10, 20, and 50 ppm, on their growth and yield were investigated. In addition, impacts on quality and storability of the fruits were also studied. In general, application of Mt was mostly more effective than that of Mj, even at 50 ppm, with regard to all evaluated parameters. However, the dual treatment at 50 ppm recorded the highest relative chlorophyll and nutrient content in date palm leaves, as well as the yield and its components. Regarding the date palm fruits stored at 4 °C for 28 days, this dual treatment recorded the lowest weight loss and fruit decay values (0.14 and 2%, respectively), the highest firmness (6 g·cm−2), total soluble solids content (36 °Brix), total sugar content (32.5 g/100 g fresh weight), and the lowest total acidity (0.16 g citric acid/100 mL juice). Moreover, the highest total phenolic content and activity of peroxidase and polyphenol oxidase enzymes in the stored fruits were also recorded for the dual treatment. In contrast to the untreated fruits, scanning electron microscopy observations showed that the sprayed fruits had a very good microstructure, showing intact and thick exocarp tissue with a dense layer of epicuticular wax. The mesocarp tissue showed a normal and clear cellular framework with well organized and arranged cells, after 28 days storage at 4 °C. Based on these results, we can conclude that application of the dual treatment (Mt + Mj) at 50 ppm is a promising way to prolong the storability of date palm fruits and maintain their quality during storage periods.

Surveillance investigations for pathogenic and toxigenic fungi are important to refine our understanding of their epidemiology and help in predicting their outbreaks. During 2019, 198 samples of wheat grains were collected from 25 wheat-growing governorates in Egypt to detect and identify seed-borne mycoflora in vitro. Forty-four fungal species belonging to 20 genera were identified. Molecular data for these fungi were analyzed to construct a phylogenetic tree. Occurrence and biodiversity indicators were calculated. Two prevalent pathogens (average incidence > 40%) were Alternaria alternata and Cladosporium spp. Ustilago tritici was present in only seven of the 25 governorates, and less abundant than Tilletia tritici, the causal agent of stinking smut. Sinai governorate recorded the greatest species diversity, while the greatest species richness was in Qena and Sohag governorates. Canonical correspondence analysis of data for 20 fungal genera with temperature, relative humidity, precipitation, wind speed or solar radiation revealed that relative humidity was the most influential weather variable. It showed that occurrence and distribution of the 20 genera corresponded well with three out of four Egyptian climatic regions: Mediterranean, semi-arid, and arid. Knowing pathogen occurrence and distribution in Egypt is the first step to developing future disease management strategies to limit yield losses and improve food security. Despite this study being conducted on the wheat-growing areas in Egypt, our findings are useful for other wheat-growing countries that share the same climatic conditions. The correlation between a given fungus and the climatic variables can be useful in other ecosystems.

Sonia Meza-Vargas, Eleni Giannouli, Magdy Younes Sleep Disorders Centre, University of Manitoba, Winnipeg, MB, Canada Introduction: The utility of multiple sleep latency tests (MSLTs) is limited to determining sleep onset latency (SOL) and rapid eye movement sleep latency. The odds ratio product (ORP) is a continuous index of sleep depth with values of 0, 1.0, and 2.5 reflecting very deep sleep, light sleep, and full wakefulness, respectively. We determined the time course of sleep depth during MSLT naps expecting that this would enhance the test's clinical utility. Methods: Thirty MSLTs (150 naps) were performed for excessive somnolence. Patients indicated whether they slept (yes/no) after each nap. SOL was scored by two experienced technologists. Time course of ORP was determined with a commercial system. We determined ORP at SOL (ORPSOL), times ORP decreased

Few reports explain the mechanism of PEG action on stomatal behavior and anatomical structure and analyze the photosynthetic pigments of in vitro date palm plantlets for better tolerance to ex vitro exposure. The main challenge for in vitro micropropagation of date palm techniques remains restricted to high survival rates and vigorous growth after ex vitro transplantation. In vitro hardening is induced by Polyethylene glycol PEG (0.0, 10, 20, 30 g L−1) for 4 weeks. Leaf anatomy, stomatal behavior, water loss %, photosynthetic pigments, and reducing sugars were examined in date palm plantlets (Phoenix dactylifera L.) cv. (Sewi) after 4 weeks from in vitro PEG treatment and after 4 weeks from ex vitro transplanting to the greenhouse. Leaf anatomy and the surface ultrastructure of in vitro untreated leaves showed a thin cuticle layer, wide opened malfunctioning stomata, and abnormal leaf anatomy. Furthermore, addition of PEG resulted in increasing cuticle thickness, epicuticular wax depositions, and plastids density, improving the stomatal ability to close and decreasing the stomatal aperture length while reducing the substomatal chambers and intercellular spaces in the mesophyll. As a result, a significant reduction in water loss % was observed in both in vitro and ex vitro PEG treated leaves as compared to untreated ones, which exhibited rapid wilting when exposed to low humidity for 4 h. PEG application significantly increased Chlorophylls a, b and carotenoids concentrations, especially 10, 20 g L−1 treatments, which were sequentially reflected in increasing the reducing sugar concentration. However, leaves of plantlets treated with PEG at 30 g L−1 became yellow and had necrosis ends with death. In vitro hardening by 20 g L−1 PEG increased the survival rate of plantlets to 90% after ex vitro transfer compared to 63% recorded for the untreated plantlets. Therefore, this application provides normal date palm plantlets developed faster and enhances survival after ex vitro transfer.

Plant facilitation has a pivotal role in regulating species coexistence, particularly under arid environments. The present study aimed to evaluate the facilitative effect of Calligonum polygonoides L. on its understory plants in coastal habitat. Forty Calligonum shrubs were investigated and the environmental data (soil temperature, moisture, pH, salinity, carbon and nitrogen content, and light intensity), vegetation composition, and diversity of associated species were recorded under- and outside canopies. Eight of the most frequent understory species were selected for evaluating their response to the facilitative effect of C. polygonoides. Bioactive ingredients of Calligonum roots were analyzed using gas chromatography-mass spectrometry (GC-MS), and mycorrhizal biodiversity in their rhizosphere soil was also assessed. The effect of Calligonum on understory plants ranged between facilitation and inhibition in an age-dependent manner. Old shrubs facilitated 18 and inhibited 18 associated species, while young shrubs facilitated 13 and inhibited 9 species. Calligonum ameliorated solar radiation and high-temperature stresses for the under canopy plants. Moreover, soil moisture was increased by 509.52% and 85.71%, while salinity was reduced by 47.62% and 23.81% under old and young shrubs, respectively. Soil contents of C and N were increased under canopy. This change in the microenvironment led to photosynthetic pigments induction in the majority of understory species. However, anthocyanin, proline contents, and antioxidant enzyme activities were reduced in plants under canopy. Thirteen mycorrhizal fungal species were identified in the rhizospheric soil of Calligonum with the predominance of Funneliformis mosseae. Thirty-one compounds were identified in Calligonum root extract in which pyrogallol and palmitic acid, which have antimicrobial and allelopathic activities, were the major components. The obtained results demonstrated that facilitation provided by Calligonum is mediated with multiple mechanisms and included a set of interrelated scenarios that took place in a species-specific manner.