خيارات البحث
النتائج 1111 - 1120 من 1,442
MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF ECTOMYCORRHIZAL FUNGI ISOLATED FROM EGYPTIAN ENVIRONMENT
2007
Mona Zayed | Sh Selim | Wedad Eweeda | M Ali | A Hazem
In a trial to isolate and identify ectomycorrhi-zal fungi for the first time in Egypt 13 sporocarpes associated with rang of plants grown on Egyptian soils were collected, to be used for this purpose. Fungal isolates were obtained from collected spo-rocarpes and tested for ectomycorrhiza formation with Bauhinia sp. and Pinus seedlings. The paper sandwich technique was used for simultaneous inoculation of root apices Bauhinia to produce synchronously developing ectomycorrhizas. Typi-cal ectomycorrhizal roots were obtained within 14 days after inoculation with the collected strains. The isolates tested for ectomycorrhiza formation with Pinus sp. to ensure their identity by for-mation of distinct root characteristics on this host. Root colonization levels varied markedly among the tested fungal strains with respect to growth enhancement and NPK uptake of Pinus shoots and roots.
اظهر المزيد [+] اقل [-]EVALUATION OF SOME WATER TRAPS FOR CONTROLLING HAIRY ROSE BEETLE ADULTS, TROPINOTA SQUALIDA SCOP. (COLEOPTERA: SCARABAEIDAE)
2007
H Hanafy
Different coloured plastic buckets (yellow, red, blue and white), filled with water were used as traps for adults of Tropinota squalida Scop. in apple orchards at El-Khatatba (El-Behaira Gover-norate) during seasons 2005 and 2006. The gen-eral mean numbers of adults/ trap were 6.0, 8.1, 14.4 and 24.1 in 2005 and 4.7, 6.7, 10.5 and 18.7 in 2006 seasons for white, red, yellow and blue traps, respectively. The general means for trap efficiency (two seasons) were 9.8, 13.7, 23.2 and 39.3 for white, red, yellow and blue traps, respec-tively. Two groups of white plastic cups, group filled with blue water solution and another group filled with water were used as traps and slung in apple trees. The general mean numbers of adults/trap were 8.1 & 7.5 for blue water solution and 5.8 & 5.2 for water traps during 2005 and 2006, respectively. The general means of trap effi-ciency (two seasons) were 36.8 and 25.9% for the above mentioned traps, respectively
اظهر المزيد [+] اقل [-]EFFECT OF DIETARY ZINC, COPPER AND IRON LEVELS ON SUPEROXIDE DISMUTASE, CATALASE AND GLUTATHIONE-S- TRANSFERASE ACTIVITY
2007
Abeer El-Dakak | Mona Ahmed | Dalia El-Nahal
The interactions between dietary zinc, copper and iron and their effects on antioxidant enzymes activity [superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST)] were examined. Fifty-four rats weighting approximately between 80-100 grams were divided into nine groups (E1- E9). Each group containing six rats was fed on basal diet with varying amount of Zn (2.5, 35 or 175 mg Zn/kg diet), Cu (1.2, 6.3, or 25 mg Cu/kg diet) and Fe (10, 50 or 230 mg Fe/kg diet). The second group (E2) was fed a diet defi-cient in all studied elements (2.5mg Zn, 1.2mg Cu, and 10mg Fe per 1 kg diet). The results of E2 showed a decrease in SOD and CAT activity and increase GST in plasma erythrocytes and tissues. Moreover, plasma thiobarbituric acid reactive sub-stances (TBARs) and hydrogen peroxide produc-tion in E2 were found to be higher than those in other groups. The high activity of lactic acid de-hydrogenase (LDH) in the plasma indicated that cell membrane damage was occurred. This dam-age was accompanied by elevation of lipid peroxi-dation and in the same time by reduction of SOD and CAT activity. Supplementation of basal diet with the different concentrations of studied miner-als led to improve the activity of antioxidants en-zymes (SOD and CAT) and decrease in TBARs and LDH activity.
اظهر المزيد [+] اقل [-]THE EFFICIENCY OF SOME PLANT EXTRACTS FOR CONTROLLING MALACOSOMA neustria (L). (LEPIDOPTERA : LASIOCAMPIDAE)
2007
Aswad Al-Mhemid
Laboratory experments and field traits were carried out on the efficiency of selected three con-centrations of each Garlic Gard extract and a mix-ture of chili oil of mustard extract (Valoram) based on fourth instar larvae of the insect. Garlic Gard extract was used in a concentrations of: 1 cm3/L, 0.5 cm3/L and 0.25 cm3/L. The mortality percentages were: 87.5 %, 83.3 % and 66.6 % respectively. The mixture of chili extract and oil of mustard extract was used in a concentrations of : 2 cm3/L, 1 cm3/L and 0.5 cm3/L The mortality per-centages were : 100%, 100% and 73% respect-tively. Garlic Gard extract when used in a field with concentrations of : 8 cm3/L, 6 cm3/L and 4 cm3/L mortality percentages were: 23.3%, 3.3% and 3.3% respectively, and for pupation were : 83.3 %, 49.9% and 36.6% respectively, also the mixture of chili extract and oil of mustard was used in a concentrations of: 20 cm3/L, 10 cm3/L and 7 cm3/L the mortality percentage: 46.6%, 6.6% and 6.6% respectively. And for pupation: 89.9%, 83.3% and 66.6% respectively. Laboratory experiments showed that the mixture of chili ex-tract and of mustard oil was highly effective against insect and more effective than Garlic Gard extract. Field traits showed that both Garlic Gard extract and the mixture of chili extract, and oil of mustard showed repellent effect and Killer materi-als to insects. The mortality percentage was high in using Valoram in comparison with Garlic Gard.
اظهر المزيد [+] اقل [-]EFFECT OF ABIOTIC AND BIOTIC TREATMENTS ON BACTERIAL ANGULAR LEAF SPOT AND PHENOLIC COMPOUNDS OF CUCUMBER
2007
S Mahmoud
Bacterial angular leaf spot disease caused by Pseudomonas syringae pv. lachrymans is one of the most important foliage disease of cucumber. The present work was planned to control the dis-ease using six inducers i.e. salicylic acid, cobalt sulphate, di-basic potassium phosphate, lithium chloride, potassium silicate and tri-potassium phosphate, in addition two bioagents named Pseu-domonas fluorescens and Bacillus subtilis were applied as foliar treatments to induce systemic resistance in cucumber plants against bacterial angular leaf spot disease. The most effective in-ducers were salicylic acid, dibasic potassium phosphate and lithium chloride, respectively. On the other hand, Bacillus subtilis was least effective one followed by potassium silicate and Ps. fluo-rescens, respectively. While, tri-potassium phos-phate, cobalt sulphate were moderate in this re-spect. Efficacy of used inducers prolonged about till six weeks after treatment.The inducers were shown to increase phenolic compounds of cucumber leaves, whereas after two weeks of treatment up to six weeks, free and total phenol in the treated plants showed higher amounts than those in the untreated ones. Another trend was obtained with conjugated phenol. A positive correlation had been noticed between ef-ficacy of inducers and accumulated amounts of free and total phenol in cucumber leaves, i.e. the higher inducer efficacy the higher free and total phenol accumulation.
اظهر المزيد [+] اقل [-]SUBCHRONIC TOXICITY OF MANCOZEB FUNGICIDE ON MALE WISTAR RATS: ULTRASTRUCTURAL ANALYSIS OF LIVER AND KIDNEY
2006
Madiha M. Talha | Kenawy M. | Salwa M. Abd-Allah
Dithiocarbamate mancozeb, an organometallic fungicide, was administered orally to male Wistar rats in two forms, pure technical 85% and formulated 80% WP, at sublethal doses of 125, 250 and 500 mg/kg b.w. for 28 days. Clinical chemical endpoints were measured after 2, 3, and 4 weeks of treatment initiation. Data disclosed that both compound formulations affected significantly serum enzyme activities particularly liver enzymes in a dose and time-dependent manner, compared with control. Such changes were accompanied with significant alterations in other parameters like; total protein, albumin, glucose, total lipids, triglycerides, cholestrol, urea, and creatinine. Furthermore, histological examination of liver and kidney showed several histopathogenic ubnormalities in the examined tissues of rats exposed to mancozeb either technical or formulated.
اظهر المزيد [+] اقل [-]ESTIMATES OF GENETIC COMPONENTS, PREDICTION AND GENETIC CORRELATION IN WHEAT (TRITICUM AESTIVUM,L.) USING NORTH CAROLINA DESIGN III
2006
Salama S.M | S.A . Awaad | Manal M. Salem
North Carolina Design III was used to estimate gene effects in bread wheat crosses. Twelve Egyptian bread wheat genotypes i.e. Sakha 69, Sakha 8, Gemmeiza 1, Gemmeiza 3, Gemmeiza 7, Giza 160, , Giza 162, Giza 164, Giza 165, Sids 1, Sids 3 and Sids 4, each was crossed back to testers, high performing (Gemmeiza 9) and low performing parent (Sakha 92) during three winter successive seasons i.e. 2002/2003, 2003/2004 and 2004/2005, to study; heading date (days) plant height (cm), flag leaf length (cm) flag leaf width (cm), flag leaf area (cm)2, extrusion length (cm), number of spikelets/spike, spike grain weight (g.), number of spikes/plant, number of grains/spike, 1000-grain weight (g.) and grain yield/plant (g.) characters. Results indicated that epistasis played great role in the inheritance of all studied characters except number of spikes/plant. Additive(D)and dominance(H) genetic variances were significant in all studied characters except number of spikes/plant and number of grains/spike. The additive genetic variance was more than dominance for heading date, plant height, flag leaf length, flag leaf width, extrusion length, spike length and 1000- grain weight. The ratio of (H./D) 0.5 was less than one for these characters but for the remaining characters the dominance genetic variance was more than additive. The values of(F) indicated that dominance was unidirectional for flag leaf length and flag leaf area, whereas it was ambidirectional for the remaining characters Prediction results revealed that it could be possible to derive reasonable proportion of new recombinants which are falling out side parental range for heading date, flag leaf length, flag leaf width, spike length, number of spikelets/spike, number of spikes/plant, 1000- grain weight and grain yield/plant. Genetic correlation indicated that additive, dominance and epistasis gene effects controlling grain yield/plant and spike grain weight, number of spikes/plant, number of grains/spike, 1000- grain weight, were signifant, suggesting common genetic pool or pleiotropy. Thus, selection based on additive genetic correlation indicated that indirect selection via, spike grain weight, number of spikes/plant, number of grains/spike and 1000- grain weight would be effective and enhance its importance as selection criteria .
اظهر المزيد [+] اقل [-]UTILIZATION OF COMBINING BIOTIC AND ABIOTIC TREATMENTS TO CONTROL BACTERIAL ANGULAR LEAF SPOT DISEASE OF CUCUMBER
2006
Wafaa Abd El-Sayed, M. | E.A.M . Gado | N.Y. Abd El-Ghafar
Bacterial angular leaf spot disease caused by Pseudomonas syringae pv. lachrymans is an important foliage disease of cucumber, under protected cultivation system. The present work was planned to control the disease using bio-agents and abiotic agents alone or combining, under greenhouse and commercial plastic house conditions. Data obtained indicated that application of bio- and abiotic agents decreased severity of bacterial angular leaf spot disease of cucumber, compared with the control. Fluorescent Pseudomonads (Pseudomonas aeruginosa, P. fluorescens and P. putida isolates) were more effectiveness than isolate of Bacillus subtilis to reduce the disease severity, when they were applied as soil drench treatment. Application of abiotic agents as foliar treatment was more effective than as seed treatment to decrease the disease severity. Isolates of P. fluorescens or P. putida as bio-agents and salicylic acid or ethephone as abiotic agents were the most effective against the disease. Disease severity was significantly reduced by increasing rates of abiotic agents. However, interaction between bio-agents (P. fluorescens or P. putida isolates) as soil treatment and abiotic agents (salicylic acid or ethephone) as foliar treatment greatly decreased severity of bacterial angular leaf spot disease of cucumber, under greenhouse and commercial plastic house condition, compared with the control. Combination between P fluorescens isolate as soil treatment and salicylic acid as foliar treatment were the most effective against the disease
اظهر المزيد [+] اقل [-]ROOT ROT DISEASE OF OLIVE TRANSPLANTS AND ITS BIOLOGICAL CONTROL
2006
M.S. Mousa, | M.K. Ali | A.A. Mosa | I.S Elewa
Several nurseries of olives in Fayoum and Giza were surveyed for root rot incidence during early summer of 2003. In Fayoum, root rot incidence reached 53% while in Giza, disease incidence was 44%. Disease symptoms consist of partial wilting, leaves browning and twig dieback, which was associated with severe root rot and basal stem cankers and followed, in most cases, by plant decline and death. The most frequently isolated fungi from rotted roots were Fusarium oxysporum, F. solani, F. moniliforme, Rhizoctonia solani, Sclerotium rolfsii, Cylindrocarpon sp. and Alternaria alternata. Isolation frequency of different fungi varied among olive cultivars. Generally, Fusarium spp. were the most frequently isolated pathogens and Fusarium oxysporum was the most frequent (35.5%) on all cultivars followed by F. solani (19.3%) R. solani (16.1%). Meanwhile, S. rolfsii, F. moniliforme, Cylindrocarpon sp. and A. alternata occurred at lowfrequencies. Pathogenicity tests showed that all tested isolates caused varied degrees of root rot symptoms on olive transplants, cvs. Manzanillo and Picual. Fusarium oxysporum, F. solani and R. solani caused the highest root rot incidence and severity on both cultivars. There was a positive correlation between disease severity on roots and severity of foliar symptoms. All evaluated olive cultivars were susceptible or extremely susceptible to fungal pathogens. All cultivars showed high disease severity with root rots, especially in response to infection by F. solani, F. oxysporum and S. rolfsii. However, the least foliar symptoms were recorded on cultivar Coratina. Application of two commercial biological control products (Rhizo-Plus and Trichoderma 2000) to soil, 24h before planting olive cuttings in the nursery, significantly reduced incidence of root rot on transplants of cultivars Manzanillo and Picual, up to 28 weeks after planting
اظهر المزيد [+] اقل [-]BIOLOGICAL CONTROL OF MELOIDOGYNE JAVANICA AND RHIZOCTONIA SOLANI ON SOYBEAN BY FORMULATION OF BACILLUS THURINGIENSIS AND TRICHODERMA HARZIANUM
2006
M.E Mahdy | E.Z Khalifa | Rania Z. El-Shennawy
Preparationof either Bacillus thuringiensis or Trichoderma harzianum were used as seed coating or soil application for management of root-knot and root rot disease complex caused by the root-knot nematode, Meloidogyne javanica and the fungus Rhizoctonia solani on soybean plants. Number of galls, root galling, egg masses and disease severity were reduced sharply on plants treated with both biocontrol agents, either as seed or soil application compared with non-treated plants. Soil application with both biocontrol agents was the best method in reducing nematode and fungus disease severity. Plant growth parameters i.e. fresh shoot and root weight, dry weight and number of pods and bacterial nodules were markedly increased with all treatments of biocontrol agent either with seed or soil treatment compared to plants grown in infested soil with either pathogens alone or combined. Results show that plant survival was more affected when R. solani was alone or combined with M. javanica. Seed coating was considered the effective method in increasing survival plants. The biochemical analysis of treated plants with both biocontrol agents were affected compared to non-treated plants grown in pathogen infested soil. The biochemical parameters i.e. chlorophyll A and B, carotein, phenols and amino acids were enhanced in bioagent treated plants compared to non-treated plants
اظهر المزيد [+] اقل [-]