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Frequency Incidence of Tomato Chlorosis Virus and Tomato Yellow Leaf Curl Virus Affecting Tomato Plants
2024
Wael El-Araby | Ahmed Al Attar | Baadawi Othman | Khaled Eldougdoug
The Tomato Chlorosis Criniviruses (ToCV) and Tomato yellow leaf curl Geminivirus (TYLCV), which naturally infecting and limited to the phloem, have caused a drastic reduction in tomato yield. The current study aims to determine the incidence of single and mixed viruses using biological, serological and molecular PCR methods in natural tomato plants. The incidence of mixed infection was found more frequently, followed by ToCV and TYLCV (42.3, 28.8, 17.8 in 2020 and 49.1, 29.7 and 19.1% in 2021, respectively). ToCV causes chlorosis, TYLCV causes leaf curl and yellowing, while mixed ToCV & TYLCV cause progress symptoms. By using the heat shock protein 70 (HSP70) and coat protein (CP) genes, ToCV and TYLCV isolates could be identified. These isolates were recorded in GenBank under accession codes "ON951644.1" and "OP265136.1" respectively. Host plants responded differently to severe and common disease density between ToCV and TYLCV. The transmitted whitefly could distinguish between ToCV and TYLCV within 15-20 minutes of the acquisition period. ToCV increases in fields with high whitefly populations, requiring further research to understand effects and reduce harm.
Afficher plus [+] Moins [-]Glutathione-S-Transferase Response Towards Imidacloprid in Honeybees (Apis mellifera L.)
2024
Hussein Ali | Basma Abdel-Aty | Walaa El-Sayed | Faiza Mariy | Gamal Hegazy
Imidacloprid is a systematic neonicotinoid widely used to combat piercing-sucking insects; however, neonicotinoids, despite having low effects on vertebrates, showed high adverse effects on honeybees (Apis mellifera L.). Glutathione-S-transferases (GST) are an important constituent of the defense system in detoxifying invading chemicals. This work examines the effects of imidacloprid on GST activity in vivo and in vitro conditions. Results revealed that there are two responses of GST activity toward IMI treatment; first, stimulation of enzyme activity to combat and detoxify the insecticide. Second, direct inhibition of GST, which is confirmed by the in vitro inhibition with IC50 887.42 ppm. At a short exposure time to IMI (2 hours) at an IMI concentration of 0.35 ppm, the enzyme was stimulated up to 113% while increasing exposure time or IMI concentration, the inhibition effect dominates.
Afficher plus [+] Moins [-]L-Ascorbic Acid Improves Fruit Setting and Activates Antioxidant Enzymes in Tomato Plants (Solanum lycopersicum L.) Grown Under Heat Stress Conditions
2024
Abdalla Abdelmonaem | Zeinab Abdou | Hany Sror | Mohamed Aboul Fotouh
Heat stress is an environmental problem that can negatively impact tomato productivity by reducing fruit setting and disrupting pollen development. The present study aims to understand the molecular mechanism of heat tolerance induced by L-ascorbic acid. Plants were grown in the summer of 2022 (day and night temperatures were 34.4°C and 25.2°C respectively). The plants were divided into two groups: one was sprayed with L-ascorbic acid (0.5 mM) and the other served as a control. Growth parameters, antioxidant enzymes, proline, hydrogen peroxide, and malondialdehyde levels in the leaves were determined. Additionally, a molecular docking allowed understanding the interaction between the antioxidant enzymes and L-ascorbic acid. Results indicated that L-ascorbic acid increased antioxidant enzyme activities (catalase, peroxidase, ascorbate peroxidase, polyphenol oxidase), proline content, fruit setting and growth indicators (shoot and root fresh and dry weight). It also reduced hydrogen peroxide and malondialdehyde levels in tomato leaves. Furthermore, the in-silico analysis revealed that L-ascorbic acid binding energies toward antioxidant enzymes were similar to those of known activators. In conclusion, foliar application of L-ascorbic acid (0.5 mM) effectively mitigated heat stress effects, activating antioxidant enzymes and eliminating reactive oxygen species, ultimately resulting in increased fruit setting.
Afficher plus [+] Moins [-]Rootability of Some Mulberry Cultivars Treated with Growth Regulators
2024
Ayat Salah El den | Hassan Elwakeel | Ahmed Awad | Mohamed Abd El-Hamed Nasser
The Red and White pakestanian mulberry cultivars and Baladi mulberry trees were propagated by using medium hardwood cuttings pre-pared in November, December and January, and treated with the growth regulators IBA and NAA (0, 2000, 4000 and 6000 ppm) during 2020 and 2021 seasons. The hardwood cuttings treatment was planted in wooden frames inside the greenhouse in a cultivation medium consisting of peat moss and sand (1:3 v/v respectively). Data showed that Baladi mulberry cultivar gave the highest values of rooting percentage while the White Pakestanian gave the highest values for the number of roots per cutting. Concerning growth regulator treatments, IBA at 6000 gave the highest significant number of roots per cutting followed by NAA at 6000 ppm. In the interaction between the two studied factors, the highest rooting percentage was found by NAA at 6000 ppm for Baladi and White cultivars. While the highest values of root number and root length were resulted by IBA at 6000 ppm followed by NAA at 6000 ppm for Baladi and White mulberry cultivars. The C/N ratio in Baladi and White cultivars cuttings was highest in hardwood cuttings prepared in November. While the values of C/N ratio in Red mulberry cultivar cuttings were highest in hardwood cuttings prepared in January.
Afficher plus [+] Moins [-]In vitro, Evaluation of Organic and Mineral Treatments Against Potato Black-leg Disease (Pectobacterium atrosepticum)
2024
Sondos Nagdy | Afaf El-Meneisy | Naglaa Balabel | Nagy Abd El-Ghaffar
Potato (Solanum tuberosum L.) is considered one of the main food crops in many countries worldwide. The present work was planned to manage potato black-leg disease using organic treatments as well as mineral-nitrogenous treatments, in addition to examining their effects on the pathogenic bacterium (Pectobacterium atrosepticum) population under artificial inoculation conditions. The obtained data indicated that applications of cabbage, onion and peppermint dry ground leaves as organic matters, and applications of ammonium super-phosphate, potassium sulfate and urea as mineral-nitrogenous fertilizers reduced P. atrosepticum population and black-leg disease of potato compared with the control treatment. In addition, these treatments led to increasing potato yield, while the beneficial effects increased with increasing their doses compared with the control treatment. Meanwhile, the organic matter appeared highly effective compared with mineral-nitrogenous fertilizers in disease reduction. However, mineral-nitrogenous fertilizers appeared highly effective in increasing potato yield. Meanwhile, onion dry ground leaves (organic matter) and urea (nitrogenous fertilizer) were the most effective on the pathogenic bacterium population and severity of the disease compared with other treatments
Afficher plus [+] Moins [-]Isolation and Characterization of Probiotics from Various Food Products as Potential Human Food Additives
2023
Fekria Mohamed Ali | Enas Hassan | Ahmed Abdelhafez | Basma Abd-Elhalim
In this study, human-safe lactic acid microorganisms (LAM) were isolated from food samples to be used as potential additives for human food. Samples from various food sources (artisanal cheeses, fermented chickpeas, fermented rice, natural yogurt, pickles, and raw milk) were used to inoculate de Man, Rogosa, and Sharpe (MRS) and malt agar plates, which were incubated at 30°C for 48 h or 37°C for 72 h to isolate lactic acid bacteria and yeast, respectively. Out of 120 isolates (85 bacteria and 35 yeast), 75 isolates showed γ-hemolytic activity and were considered “Generally Recognized As Safe” (GRAS) isolates. After testing their growth rate under the gastrointestinal tract (GIT) conditions, including acidic pH and specific bile salt concentrations, we selected 30 isolates. Then, we evaluated the fermentative abilities of these 30 isolates on nine types of carbohydrates, their total acidity, and their antagonistic activity against five human pathogens. Based on the results of these tests, four isolates were selected for identification using the Biolog program and 16S rRNA sequencing for bacteria and 18S rRNA sequencing for yeast and found to be Bacillus bingmayongesis (FJAT-13831), Lacticaseibacillus paracasei (R094), Pediococcus pentosaceus (DSM 20336), and one yeast isolate as Saccharomyces cerevisiae (SaCe1 26S).
Afficher plus [+] Moins [-]The Potential Efficiency of Lactobacillus farraginis Isolated from Ruminants with a View to be Used as Animal Probiotics
2023
Mona Zayed | Dalia Abd El-Fattah | Rateb Abbas | N. El-Bordeny | Sherif Edris
Probiotics refer to microorganisms that exhibit a beneficial effect on the animals’ health through intestinal microbial balance. This investigation intends to identify and define the probiotic characteristics of Lactobacillus strains isolated from the digestive systems of ruminants. Bacterial strains were isolated purified and characterized based on morphological and biochemical characteristics. The isolates were identified using the 16S rRNA gene partial sequencing method. Most of the strains exhibited a decrease in the growth by increasing the concentration of the bile salt, NaCl, increasing the temperature over 37oC, and moving toward neutrality and alkalinity of the media. Strain Lactobacillus farraginis MD_A11 revealed the lowest decrease in the growth percentage when subjected to different bile salt concentrations of 5.96, 6.61, 6.85, 7.40, 7.53, and 7.64%, NaCl% concentrations of 1.40, 5.62, 6.48, 7.36, 7.39, 7.41, 7.42, 7.28, and 13.76%, raising the temperature over 37oC being 4.19 & 3.945%, different pH levels as compared to control, and it recorded the lowest medium pH after the third day being 4.20 with titrable acidity of 0.32%. Strain Lactobacillus farraginis MD_A11 could be recommended as a probiotic feed additive for ruminants to improve their growth performance and productivity.
Afficher plus [+] Moins [-]Residue Assessment of Bifenazate, Spirodiclofen and Abamectin in Strawberry Fruits Under Field Conditions
2023
Eman Abdelmaksoud | Walaa Elsayed | Shoukry Elrefai | kadry mahmoud | Khaled Ramadan
The dissipation behavior of three pesticides, bifenazate, spirodiclofen and abamectin was studied in strawberry fruits using a modified QuEChERS extraction technique. The residues of the tested acaricides were determined under field conditions after 1 hour (zero days), 1, 3, 7, 14, and 21 days. The maximum residue limits (MRLs) were 2, 2, and 0.15 mg/kg for bifenazate, spirodiclofen and abamectin, respectively. The strawberry fruits could be used safely after 15 days from bifenazate spraying and after 3 days from spirodiclofen spraying. The concentration of abamectin after 21 days did not reach MRL. The half-life values (t1/2) of bifenazate, spirodiclofen, and abamectin in strawberry fruits were 0.99, 0.86, and 5.7 days, respectively.
Afficher plus [+] Moins [-]Effect of Pruning Levels on Yield and Fruit Quality of Melody (Blagratwo) Seedless Table Grape Cultivar
2023
Ali Ali | Nazmy Abdle Hamid | Amin shaddad | Mohamed Nasser
Three years old uniform vines for cv. "Melody syn. Blagratwo" seedless table grape were selected, and three levels of bud load were trimmed, namely 60, 72, and 78 buds/ vine. The findings revealed that vegetative growth traits, characteristics of yield and bunch quality were significantly affected by all different pruning levels of cane length in both seasons of this study. Highest bud load vines (78 buds/vine) produced the greatest yield and cluster number but had a negative effect on the percentage of bud behavior, shoot thickness, shoot length, weight of annual pruning (Kg/vine), cluster and berry quality parameters. In contrast, lowest vine bud load (78 buds/vine) had a better bud behavior, vegetative growth traits, cluster characteristics and berry characteristics but both bunch numbers and yield were reduced. In addition, vines pruned with bud load of 72 buds per vine significantly showed the best outcomes, since it successfully struck a balance be-tween features of vegetative growth, yield, cluster and berry physical and quality attributes in both seasons.
Afficher plus [+] Moins [-]Evaluation of Certain Synthetic and Natural Pesticides Against Whitefly Bemisia tabaci (Genn.) on Green Bean and Effect on Honeybee Apis mellifera L.
2023
Sharihan Ahmad | Walaa Abdelghany | Ahmed Ahmed | Sawsan Abdelmegeed
The green bean crop (Phaseolus vulgaris) is infested with many insects such as whiteflies (Bemisia tabaci). An investigation was carried out to study the insecticidal activity of whitefly (Bemisia tabaci), five pesticides were used, namely Thiamothoxam, Sulfoxaflor, Spirotetramat, Pymetrozine, and Flonicamid, and three commercial natural pesticides, namely Superrego, Topnine, and Bernastar. Pesticides and natural pesticides were sprayed during the two seasons of 2020 and 2021. The obtained results in terms of the reduction rate of the insects' number were as follows: The highest rate of reduction appeared in Thiamothoxam and Sulfoxaflor treatments, where it reached above 80%, while the other pesticides were in the range of 40% to 60%, and the lowest reduction rate was 34.33% and 36.00 % for Bernastar during season 2020 and 2021 respectively. When evaluating the toxicity of these pesticides and natural pesticides against honeybees (Apis mellifera), the pesticides did not reveal any toxicity to honeybees, except for Thiamothoxam, Sulfoxaflor, and Superrego The LC50 and LD50 values against honeybees were 0.2 ppm and 0.000005µg/one honeybee for Thiamothoxam, 4.5 ppm and 0.0001125 µg/one bee for Sulfoxaflor, and 0.95 ppm and 0.00002375 µg /one bee for Superego respectively.
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