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Morphological and Molecular Identification of Penicillium digitatum Causing Green Mould of Citrus Fruits in Egypt
2023
Desouki, Abdalrahman | Ahmed Reda, Labiba | Rashed, Mohamed | Shehata, Shehata
Nine Penicillium digitatum isolates were isolated from citrus fruits and tested for their pathogenicity on Navel orange fruit (Citrus sinensis L.). In this regard, the isolates exhibited three different levels of virulence. The isolates were identified morphologically using malt extract agar (MEA) and Czapek yeast extract agar (CYA) for colony characteristics, and MEA for microscopic features. Each one of the isolates has the unique features of P. digitatum, especially the largest conidia (6.1-11.9 µm long X 3.2-8 µm width), and phialides (10.1-21.4 µm long X 4-5.1 µm width). In addition, the isolates were identified on a molecular basis using ITS1 and ITS4 primers to confirm morphological identification. Phylogenetic analysis revealed that there was high variance among the isolates, and there were different relations between some of our isolates and other P. digitatum registered strains originating from different countries all over the world. The sequences were submitted to respective GenBank nucleotide databases with accession No. OR198852, OR198853, OR198854, OR198855, OR198856, OR198857, OR198858, OR198859 and OR198860. We also isolated a new P. digitatum (OB15: OR198859) strain with high virulence and rapid sporulation
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
Ahmad, Sharihan | Abdelghany, Walaa | Ahmed, Ahmed | Abdelmegeed, Sawsan
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.
Afficher plus [+] Moins [-]Description of Leafhopper, Hebata (Alboneurasca) decipiens (Paoli, 1930) and Its Transmitting Phytoplasma Infesting Sugar Beet Plants
2023
Ibrahim, Heba | Abdelrahman Emam, Azza | Bondok, Ahmed | Ahmed, Magdy | Abd-Elraheem, Amro
The second sugar crop of sugar production after sugar cane world-wide is sugar beet (Beta vulgaris L.). This plant is subjected to the infestation of several insect pests that cause considerable damage, especially leafhoppers, that can transmit phytopathogens (e.g., phytoplasma). In this work, we identified and described the leafhopper, Hebata (Alboneurasca) decipiens, in addition to detection and molecular identification of Candidatus Phyto-plasma that was transmitted by this leafhopper on sugar beet plants from naturally infected sugar beet plants to an uninfected one. The 16S rDNA gene from phytoplasma was amplified by a nested polymerase chain reaction (PCR) assay and directly sequenced using specific primer pairs DNA fragments. The resulting sequences were analyzed and compared with another phytoplasma sequence available at GenBank sequences performing BLAST using DNAMAN.
Afficher plus [+] Moins [-]Molecular Identification of Some Rhizobium and Serratia Isolates as Potential Producers of Indole-3-Acetic Acid
2023
Sello, Shaimaa | Abdel Razik, Ashraf | Ibrahim, Samir | Elateek, Sawsan
In order to reduce the use of chemical fertilizers, the use of biological inoculants has been increased. Beneficial microorganisms are used to increase crop yields by stimulating plant growth through the production of phytohormones. In the present study, Indole Acetic Acid (IAA) production was analyzed in 18 bacterial isolates with Plant Growth-Promoting (PGP) capabilities; 15 of these isolates were Rhizobium, and three were Serratia. All isolates have been characterized morphologically and biochemically, and their IAA production in the presence of tryptophan, a precursor for IAA biosynthesis, has been evaluated. IAA production was detected using the Salkowski reagent with CT-2200 spectrophotometer at 530 nm. The levels of IAA production varied between the different isolates. The top two IAA producers were selected for genetic identification using 16SrRNA primers (27F and 1492R). One of the Rhizobium isolates (NRC-R2) shared 95% sequence similarity with Rhizobium sp., according to a Blastn search in GenBank and Rhizobium leguminosarum, whereas the Serratia isolate (Ain Shams Center for Genetic Engineering and Biotechnology (ACGEB)-S2 was 99.5% similar to Serratia sp. In the near future, it is possible that these two isolates could serve as biological sources for IAA.
Afficher plus [+] Moins [-]Effect of Pruning Levels on Yield and Fruit Quality of Melody (Blagratwo) Seedless Table Grape Cultivar
2023
Ali, Ali | Abdle Hamid, Nazmy | shaddad, Amin | Nasser, Mohamed
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 [-]Partial Gap-Filling of the Nile Tilapia Oreochromis niloticus Draft Genome
2023
Zoghly, Hala | Rashed, Mohamed | Magdy, Mahmoud
Nile tilapia is a freshwater fish of African origin, with productive and economical characteristics affecting global fish markets. The Oreochromis niloticus reference genome has a diploid set of 22 linkage groups (LGs) in addition to ungrouped sequences. A total of 42,622 genes have been identified, but 550 genomic gaps may include more. Our study focused on some of these genomic gaps, where appropriate primers were designed and then multiplied through the polymerase chain reaction (PCR) technique. From local samples, DNA was extracted and amplified with the new primers. Successful amplicons were sequenced and annotated using available bioinformatics tools. Five assessed sequences were annotated, of which three were newly predicted in O. niloticus, as mucin 1-like, and KLR genes, and SATB region. The other two sequences belonged to grid2 and trpm7 which were previously predicted. Although individual attempts to identify genomic gaps are not feasible in filling the large lack of information on the Nile tilapia genome, a good number and valuable new information has been reached. How-ever, the following plan showed many technical problems, more time, effort, and cost that could be avoided by suggesting the application of another technique, such as whole-genome sequencing, mapping, and assembly.
Afficher plus [+] Moins [-]Effect of Gamma Radiation on Ephedrine and Pseudoephedrine in Callus and Suspension Cultures of Ephedra alata
2023
Abdelsalam, Naglaa | Abd El-Aal, mona | Aboul Fotouh, mohamed | Reda, mohamed | Safe, Ibrahim
Ephedra is the most widely and largest widespread genus in the Gnetopsida, a subgroup of the gymnosperms. This research was done to find out how gamma radiation affected the in vitro growth of callus and suspension cultures. In addition, the effect of gamma rays (γ-rays) on the ephedrine and pseudoephedrine concentrations was evaluated through HPLC analysis. The cell suspension and callus cultures were formed on Murashige and Skoog's basal medium (MS) supplemented with 0.5 mg/l kinetin (Kn), and 3 mg/l of 2, 4-dichlorophenoxy acetic acid (2,4-D) and exposed to variable gamma radiation doses (0, 5, 10, 15, 20, 25 and 30 Gray). Highly significant differences in both fresh and dry callus weights were recorded due to the effect of gamma rays (γ-rays). The findings demonstrated that in the cell suspension and callus cultures, 15 Gray achieved the highest fresh and dry weights when compared to the control. Similarly, the highest concentrations of ephedrine and pseudoephedrine were found in suspension and callus cultures compared to control at 15 Gray.
Afficher plus [+] Moins [-]Efficacy of Potassium Fertilizer and Certain Pesticides for the Management of Brinjal Fruit Infection by Shoot Borer [Leucinodes Orbonalis (Guenée)]
2023
bhandari, Sagar | kandel, Bikash | gyawali, Pramod | pokhrel, Saurav | ojha, Sushil | bhandari, Sarita
The research aims to evaluate the efficacy of different levels of potassium fertilizer (8 g/plant K2O) as well as the insecticides neemix, spinosad, and imidacloprid at the rates of 6 ml, 0.33 ml, and 0.33 g/L water, respectively, for the management of brinjal fruits and shoot borer. The two-factor randomized complete block design with three replications was used. Significant minimum shoot damage was recorded in the plots treated with imidacloprid (0%), spinosad (1.67%) and neemix (5.0%) at 81 days after planting. Similarly, a significant minimum fruit infestation (2.90%) was recorded with imidacloprid, which was lower than those of spinosad (15.16%) and neemix (19.63%). The application of potassium fertilizer at a rate of 8 g/plant showed a significant reduction in shoot infestation (2.50%) 81 days after planting. The minimum percentage yield of infested fruit was reported with spinosad (1.03%), which was at par with other insecticidal treatments. Considering the negative impacts of chemical pesticides, neemix 6 ml/L water in combination with potassium fertilizer at 8 g/plant is recommended.
Afficher plus [+] Moins [-]The Relationship Between Vegetation Type and Population Density-Diversity of Spiders in Certain Vegetable Crops
2023
Abd El-Karim, Hamdi | Rizk, Marguerite
The experiment was carried out on three different vegetable crops, Cucumber Cucumis sativus L. (Cucurbitaceae), eggplant Solanum melongena L. (Solanaceae) and okra Abelmoschus esculentus L. (Malvaceae), during summer 2021, to investigate the effect of vegetation type on spider density and diversity. For this study, the pitfall trap method was used to collect spiders from the soil surface to ensure a comprehensive representation of all spider guilds. During this study, 20 species belonging to 6 families were collected. The results showed that a total of 374, 285 and 194 individuals belonging to 18, 17 and 15 species were recorded in okra, cucumber and eggplant fields respectively. Species diversity was greater in okra cultivation. Results also indicated that the Lycosidae family was the most abundant and dominant, representing 71.75%, followed by the Linyphiidae family of 90 individuals representing 10.55% of the whole obtained population. The most dominant species were Wadicosa fidelis 152, 98 and 67 individuals and Pardosa injucunda 111, 69 and 52 individuals in okra, cucumber and eggplant respectively. It is inferred from this study that the type of plant can have an impact on spider communities.
Afficher plus [+] Moins [-]Evaluation of Biologically Treated Olive Mill Wastewater for Irrigation of Pea Plant
2023
Abdelhafez, Ahmed | yehia, Rokia | Abdelaal, Azza
This study evaluated the use of biologically treated olive mill wastewater (OMWW) for irrigation of pea plants, rather than discharging this nutrient-rich liquid and polluting the environment. Pea seeds were planted in pots containing soil irrigated with tap water (control), untreated (crude) OMWW, or OMWW treated with the fungus, Pleurotus columbinus, or algae Spirulina platensis or Wollea sp., with two NPK rates. Plant length shoot and root dry weight, nitrogen, phosphorus, potassium, chlorophyll, and carotene contents were measured, along with to nitrogenase and dehydrogenase activity. The highest shoots N and P content were recorded in plants irrigated with Sp. Platensis-treated OMWW + 100% NPK; while the highest K content was in plants irrigated with crude OMWW + 100% NPK. The highest dehydrogenase activity, 59.01 μg TPF/100 g soils, was recorded in plants irrigated with P. columbinus-treated OMWW supported with 75% NPK, while maximum nitrogenase activity (261.82 μmol/100g soil/day) occurred in plants irrigated with Wollea sp.-treated OMWW with 75% NPK. The highest content of chlorophylls a & b and carotene (0.838, 0.276, 0.252 mg/g dry weight, respectively) were found in plants irrigated with OMWW treated with Wollea sp. and 100% NPK. Thus, biologically treated OMWW showed promising impacts on plant growth parameters.
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