检索结果-南通市图书馆

Production and Optimization of Pseudomonas fluorescensBiomass and metabolites for Biocontrol of Strawberry Grey mould

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2012年第7期3卷 836-845页

作者： wafaa m. haggag mostafa Abo El Soud Biotechnology and Genetic Engineering Unit National Research Center Dokki Cairo Egypt. Department of Plant Pathology National Research Centre Dokki Cairo Egypt

Pseudomonas species have been widely studied as biological agents (BCAs) and it is alternative to the application of chemical fungicides. Our objective was to optimize nutritional and environmental conditions of the isolated Pseudomonas fluorescens fp-5 for biomass and metabolites production and to evaluate itsagainst the grey mould disease caused by Botrytis cinerea on strawberry plants under field conditions. Pseudomonas fluorescens, showed antagonistic properties, in vitro, against thepathogen Botrytiscinerea. Effect of the separated secondary metabolites on the fungal growth by broth dilution technique and antifungal activity by agar well diffusion technique was studied. Response surface methodology was used to investigate the effects of four fermentation parameters (pH, incubation time, carbon and nitrogen concentrations) on biomass and bioactivemetabolites [antibiotic phenazin and siderophore] production. Glycerol was found to be the best carbon source for improved biomass and metabolites production. meanwhile, peptone and yeast extract were found to be the best nitrogen source. Analysis of each formulation revealed that glycerol oil at 0.01% the best oil used for protect P. fluorescens for 3 months Under natural condition, P. fluorescens formulation was effective in reducing B. cinerea disease in strawberry leaves and fruits. Pre-harvest treatment protected fruits from Botrytis post-harvest disease in comparing of fungicide. In addition, the obtained results showed that bacterial treatment significantly increased thegrowth parameters as well as dry weights and yield.

关键词： Botrytis Bunch Rot Pseudomonas fluorescens Strawberry Blight

Pilot-scale production and optimizing of cellulolytic Penicillium oxalicumfor controlling of mango malformation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2013年第4期4卷 165-174页

作者： wafaa m. haggag mostafa Abo El Soud Biotechnology and Genetic Engineering Unit National Research Center Cairo Egypt Department of Plant Pathology National Research Center Cairo Egypt

Penicillium oxalicum Curie et Thom isolated from blossom of mango (var. Saddekia) was evaluated against mango malformation incited by Fu- sarium subglutinis. Both in vitro and in vivo conditions. The mechanism of this isolate for controlling Fusarium was the reduction of growth development. The Penicillium oxalicum isolate produced extracellular cellulolytic enzymes (exo-glucanase or cellobiohydrolases and endo-glucanase, that possibly related to the biocontrol process. Optimize and fermentation conditions (growth period, carbon and nitrogen sources) for spores and cellulolytic enzymes production were determined. Liquid formulation containing (6 × 106) with sodium alginate (0.5%) and Tween 80 (0.01%) was used. For field evaluation, susceptible cultivars as Ewais, Saddika, Alphonso, Taimour and Zebda were selected. Liquid bioformulations were sprayed twice and 30 days intervals. The spray was initiated from pre-flowering stage. Bioformulation was found to be significant in reducing the malformation incidence. Results cleared that spraying of liquid bioformulations, substantially improved the fruit numbers and yield for the five mango cultivars and suggested to be most promotive for fairly quality in tested cultivars.

关键词： Antagonist Biocontrol Fusarium subglutinis mango malformation Penicillium oxalicum

Anti-Synchronization of Chaotic Systems via Adaptive Sliding mode Control

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第12期29卷 36-38页

作者： wafaa Jawaada m.S.m.Noorani m.mossa Al-sawalha School of mathematical Sciences Universiti Kebangsaan Malaysia43600 UKM BangiSelangorMalaysia Faculty of Science Mathematics DepartmentUniversity of HailKingdom of Saudi Arabia

An anti-synchronization scheme is proposed to achieve the anti-synchronization behavior between chaotic systems with fully unknown parameters.A sliding surface and an adaptive sliding mode controller are designed to gain the *** stability of the error dynamics is proven theoretically using the Lyapunov stability *** numerical results are presented to justify the theoretical analysis.

关键词： parameters. theory. stability

Glassy behaviour of random field Ising spins on Bethe lattice in external magnetic field

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2011年第6期20卷 416-425页

作者： Khalid Bannora Galal Ismail wafaa Hassan mathematics Department Faculty of Science Zagazig University mathematics and Physics Department Faculty of Engineering Port Said Branch of Suez Canal University

The thermodynamics and the phase diagram of random field Ising model （RFIm） on Bethe lattice are studied by using a replica trick. This lattice is placed in an external magnetic field （B）. A Gaussian distribution of random field （hi） with zero mean and variance （hi2 = H2RF is considered. The free-energy （F）, the magnetization （m） and the order parameter （q） are investigated for several values of coordination number （z）. The phase diagram shows several interesting behaviours and presents tricritical point at critical temperature Tc = J/k and when HRF = 0 for finite z. The free-energy （F） values increase as T increases for different intensities of random field （HRE） and finite z. The internal energy （U） has a similar behaviour to that obtained from the monte Carlo simulations. The ground state of magnetization decreases as the intensity of random field HRF increases, The ferromagnetic （Fm） paramagnetic （Pm） phase boundary is clearly observed only when z →∞. While Fm Pm-spin glass （SG） phase boundaries are present for finite z. The magnetic susceptibility （X） shows a sharp cusp at Tc in a small random field for finite z and rounded different peaks on increasing HRF.

关键词： random field replica trick coordination number order parameter susceptibility and phase diagram

mass production, fermentation, formulation of Pseudomonas putidafor controlling of die back and phomopsis diseases on grapevine

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advances in Bioscience and Biotechnology 2013年第6期4卷 741-750页

作者： wafaa m. haggag malaka A. E. Saleh Inas mostafa Noran Adel Biotechnology and Genetic Engineering Unit Dokki Egypt Pathology Department National Research Centre Dokki Egypt Pomology Department National Research Centre Dokki Egypt

The export oriented agricultural and horticultural crops depends on the export of residue free produce and has created a great potential and demand for the incorporation of biopesticides in crop protection. PGPR with wide scope for commercialization includes Pseudomonas putida. Pseudomonas putida was effective in reducing die back caused by a fungus Botryodiplodia theobromae and phomopsis or arm death, caused by a fungus, Phomopsis viticola of grapevine in vitro and in vivo. Pseudomonas putida showed optimum Siderophore pseudobactin production at 72 h, and growth peak at 120 h. glycerol as a source of carbon and yeast as a source of nitrogen Pseudomonas putida was formulated using polysaccharide dextran starch, which led to the elongation of conservation and the effectiveness of the biofungicide. Pseudomonas putida was very effective as biocontrol agents to reduce the die back and phomopsis diseases on grapevine. The obtained results showed that both bacterial treatments significantly increased the growth parameters as well as fruits dry weights and yield of grapevine.

关键词： Die Back Phomopsis Diseases Grapevine and Pseudomonas putida

Glassy phase and thermodynamics for random field Ising model on spherical lattice in magnetic field

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2010年第10期19卷 525-533页

Phase diagram and thermodynamic parameters of the random field Ising model （RFIm） on spherical lattice are studied by using mean field theory. This lattice is placed in an external magnetic field （B）. The random field （hi） is assumed to be Gaussian distributed with zero mean and a variance （hi2） = HRF2. The free energy （F）, the magnetization （m） and the order parameter （q） are calculated. The ferromagnetic （Fm） spin-glass （SG） phase transition is clearly observed. The critical temperature （Tc） is computed under a critical intensity of random field HRF = V/2/πJ. The phase transition from Fm to paramagnetic （Pm） occurs at TC = J/k in the absence of magnetic field. The critical temperature decreases as HRF increases in the phase boundary of Fm-to-SG. The magnetic susceptibility （X） shows a sharp cusp at TC and the specific heat （C） has a singularity in small random field. The internal energy （U） has a similar behaviour to that obtained from the monte Carlo simulation.

关键词： random field mean field theory magnetization specific heat and phase diagram

mango malformation: I. Toxin Production Associated with Fusarium Pathogens

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2011年第2期2卷 276-281页

作者： wafaa haggag m. Hazza m. Sehab A. Abd El-Wahab m. 不详

Eight Fusarium species i.e. F. subglutinans, F. solani, F. oxyspoum, F. sterilihyphosum, F. proliferatum, F. monili-forme, F. avena and F. chlamydspore isolated from mango malformed disease were tested for their ability to cause mango malformation disease and their production of moniliformin and total fumonisins (FB1 + FB2) using HPLC. A evaluated for moniliformin production, seven isolates were toxin producers, the production levels ranging from 0.51 to 8.90 μg/ml. The higher levels were produced by Fusarium subglutinans (8.51 μg/ml). moderate concentrations of moniliformin was produced by *** (6.90 μg/ml), F. oxysporum (6.30 μg/ml), F. proliferatum (4.10 μg/ml) and F. sterilihyphosum (1.10 μg/ml). Separation and identification of Fumonisin that was isolated from the pathogen- causing disease are made by (HPLC). A evaluated for total fumonisin production (FB1 + FB2), seven isolates were toxin producers, the production levels ranging from 0.10 to 8.30 μg/ml. The higher levels were produced by F. monili-forme (8.30 μg/ml. moderate concentrations of fumonisin was produced by F .proliferatum (0.64 μg/ml) and F. subglutinans (0.50 μg/ml). Strong positive correlations between moniliformin and total fumonisins (FB1 + FB2) activities and malformation disease incidence by F. subglutinans, F. solani, F. oxyspoum, F. sterilihyphosum, F. proliferatum was observed.

关键词： Fusarium mango malformation moniliformin And Fumonisins

molecular identification of mango malformation pathogens in Egypt

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Bioscience and Biotechnology 2011年第4期2卷 226-232页

作者： wafaa m.haggag m Hazza m. m Saker m. Abd El-Wahab Department of Plant Pathology National Research Center Cairo Egypt

Diagnostic tests by molecular biology is made for studying the relations among Fusarium species for linking production of proteins, degree of relationship and occurrence of malformation. Determination of proteins for isolates causing-disease by SDS-PAGE explained there’s specific band for each fungus and there are common bands among some isolates of fungi. Since, band with mW 30 KDa represented only in F. proliferatum and F. oxysporum and F. subglutinans respectively. This band considered as specific band for these isolates, which released high pathogenisity effect. RAPD–PCR markers were used to discriminate variations between Fusarium isolates and causing disease. There is specific band for each fungus which act as molecular marker for each fungus and there are some bands common among some isolates of pathogenic fungi. The dendrogram shows there is degree of relationship between F. sterilihyphosum and F. proliferatum;between F. moniliforme and F. subglutinans;between F. oxysporum and F. chlamydospore;the degree of relationship among F. subglutinans, F. proliferatum and F. sterilihyphosum and degree of relationship among F. moniliforme, F. sterilihyphosum, F. proliferatum and F.

关键词： Fusarium Spp. mango malformation

mango malformation: II. mangiferin changes associated with fusariumpathogens

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2011年第3期2卷 291-296页

作者： wafaa m. haggag mahmoud Hazza mohamed E. Abd El-Wahab Department of Plant Pathology National Research Center Dokki Cairo Egypt Department of Plant Pathology National Research Center Dokki Cairo Egypt Science Faculty Botany Department Banha University Egypt

mangiferin (1,3,6,7-tetrahydroxy xanthone-C2-b-D-glucoside) promoted vegetative growth and exhibited inhibitory role on the occurrence of malformation. mangiferin changes associated with mango malformation pathogens were followed after inoculated mango seedlings (three years) with malformation pathogens i.e. Fusa-rium subglutinans, F. sterilihyphosum, F. oxysporum and F. proliferatum. mangiferin remained at lower level in leaves of malformed shoots as compared to healthy one. The floral malformation was observed to be associated with the reduction of mangiferin. Strong positive correlations between mangiferin activity and malformation incidence were observed. mangiferin level at panicle initiation may give a possible estimate of malformation incidence in mango.

关键词： Fusarium mangiferin mango malformation