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BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF SOME YEAST ISOLATES
2007
A. Abulhamd | M Mokhtar | Rasha Farrag,
Sixteen yeast isolates from various sources in-cluding molasses, foodstuffs, concentrated juices and soils were identified using simplified API 20 C AUX yeast identification system and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). The isolates were found to belong to 11 species; Candida famata, C. glabra-ta, C. krusei / inconspicua, C. norvegensis, C. col-liculosa, Cryptococcus humicolus, Rhodotorula mucilaginosa, Kloeckera spp., Geotrichum capita-tum and Saccharomyces cerevisiae. API and RAPD-PCR proved to be useful and convenient taxonomic tools for rapid identification at the spe-cies level, proving that at least two techniques are needed for precise identification. RAPD-PCR pro-cedure is faster than traditional characterization techniques; the identification of a single colony was typically achieved in less than 10 hr.
Показать больше [+] Меньше [-]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.
Показать больше [+] Меньше [-]EFFECTS OF PLANTING DATE ON WATER REQUIREMENTS OF MAIN VEGETABLE CROPS IN SAUDI ARABIA
2007
J Basahi
The effects of planting date on the evapotran-spiration (ETC) were studied for Tomato, Egg-plant, Squash, Cucumber, Carrot, Potato, Onion, and Watermelon, in Riyadh, Makkah, Njran, Al-Qassim, Eastern region, Tabuk, Al-Jouf, Aseeir, Al-Madenah, Hail and Jazan Regions based on the crop pattern in each region. The ETC of each crop was estimated based on Penman-Monteith Equa-tion. The results showed that the ETC for crops planted in January, February, March, April or Maywere higher than those crops planed in September, October, November, or December. The average ETC was higher when planting date was closer to summer months (June, July and August). Also, the results showed differences in ETC among the dif-ferent regions. The ETC in Al-Madenah region was higher than the other regions for Tomato and Eggplant. While, Riyadh region had the highest ETC values compared with the other regions for Squash, Cucumber, Carrot, Potato, Onion, and Water melon
Показать больше [+] Меньше [-]MONITORING THE EFFECT OF SOME INSECTICIDES FOR CORN STEM BORER CONTROL, AT DEIR EZ-ZOR REGION, SYRIA
2007
M Idraw | E. Al-Jouri
The corn stem borers larvae (species Sesamia cretica Led., Sesamia nonagrioides Lef. and Os-trinia nubilalis (Hübner)) are considered the major pests attacking Zea mays L. The larvae bore into stems and ears which cause a significant decrease of both quantity and quality of yield. This research was completed at Eastern region of Syria during 2004 and 2005 corn growing season, aiming to control these corn borer species with some insec-ticides; Avaunt 150SC (Indoxacarb 150 g / L),Sumialpha 5EC (Esfenvalerate 50 g / L), Proclaim 05SG (Emamectin benzoate 50 g / Kg), Comply 25WP (Fenoxycarb 205 g / Kg) and Agerin 6.5WP (Bacillus thuringiensis kurstaki 32000 IU / Mg). The results showed that in corn attacked by Sesa-mia cretica, Sesamia nonagrioides and Ostrinia nubilalis the infested rate reached up to 38 % on stems and 18.5 % on ears at control plots. Results also showed high efficacy of insecticides Avaunt 150SC, Sumialpha 5EC, Proclaim 05SG, Comply 25WP and Agerin 6.5WP in reducing the infested rate in stems to about 6, 8.1, 11.5, 13.5 and 21.2 %, respectively. And to about 4.5, 6.1, 7.2, 7.9 and 11.1 % in ears by Avaunt 150SC, Sumialpha 5EC, Proclaim 05SG, Comply 25WP and Agerin 6.5WP, respectively. These results gave rise to a positive increase in the yield of corn seeds.
Показать больше [+] Меньше [-]PROLINE ACCUMULATION IN DURUM WHEAT (Triticum durum Desf) UNDER WATER DEFICIT
2006
Chaib, Ghania | M. Benlaribi
Proline’s content was estimated in different organs of durum wheat; dry wheat seeds (caryopsis), seeds during germination, second and third leave’s level in different degrees of water alimentation: 75%, 50.0, 42.5, 35.0, 25.0 and 12.5% of the field capacity. Four genotypes of durum wheat Triticum durum DESF were studied from three different origins; Algeria, France and Mexico. Results showed that proline’s content was low in dry wheat and in seeds during germination, and increased by decrease of water supplies. This amino acid estimation during experimentation, allowed us to classify the studied genotypes into 3 main groups: - Genotypes with high proline accumulation (Mexicali). - Genotypes with low proline accumulation (Clairdoc). - Two intermediate genotypes MBB and OZ. These differences among genotypes can be exploited in parietal selection with relation towater deficit.
Показать больше [+] Меньше [-]EVALUATION OF SOME MALE TYPES AS POLLINATORS FOR BARHI DATE PALM cv. GROWN IN EGYPT
2006
A.H Al-Hamoudi | A.M. El-Hammady | I.M Desouky | A . Abdel-Hamid
Four different date palm male types were chosen to evaluate which male could be recommended to use as a pollinator for Barhi date palm cv. grown in Egypt. Three male types namely Ghanamy, Fard and Boyr were grown in the Fruit Trees Experimental Station at Dibba, Fojaira, UAE, and the fourth male was an individual Sewy satellite seedling grown in Egypt. Number of spathe/palm; spathe weight, length, & width ; pollen grains weight / spathe ; average of strand length as well as pollen grains germination % were determined for each male date palm tree from each male type . Moreover, pollen grains from each male type were used as a pollinator to evaluate their effect on fruit set and fruit quality of Barhi date palm cv. This study was carried out during both 2004&2005 seasons. Data showed that both Ghanamy and Fard male type were superior in their morphological characters as compared with Boyr or Sewy satellite seedling male type. Boyr male type showed the lowest values of morphological characters. On the other hand, there were no great differences in pollen grains germination percentage. Moreover, the results clearly indicated that Ghanamy pollen recorded the highest significant fruit set percentage and bunch weight (Kg) in both seasons of study. While, Fard pollen produced the highest fruit weight (g), length, diameter, flesh weight& thickness and flesh %. Boyr and Sewy pollen showed the highest ratio of fruit length / diameter in both seasons. Data also revealed that dates that were picked from bunches pollinated with Fard pollen had the highest total soluble salts (T.S.S) value and the lowest tannins content.
Показать больше [+] Меньше [-]STUDIES ON BACTERIAL POLLUTION IN LAKE MANZALA
2006
D.S. Ghaleb ; Abduljalil | A. Thabet Jamil | F.A Mansour | A Ismail | M.M . Zaky | M.I. Abou-Dobara
Lake Manzala in Egypt have shown great changes in water properties including pH (7.4 to 8.4), total suspended solids (19 to 350 mg/l), total dissolved salts (1578 to 33480 mg/l), dissolved oxygen (2.25 to 8.45 mg/l), ammonia (0.00 to 44.8 mg/l) and nitrate (0.00 to 8.96 mg/l). In addition there has been quite high bacterial density in water and fish of the lake, including total viable bacterial counts and indicator organisms such as total coliforms, faecal coliforms and some other organisms such as Aeromonas spp., Vibrio spp. and Staphylococcus spp. However, the magnitude number of bacteria in water and fish was found to vary sometimes considerably and sometimes slightly depending on the site of sampling. Our results herein showed that LakeManzala is highly contaminated.
Показать больше [+] Меньше [-]SCREENING OF ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF SOME ACTINOMYCETES ISOLATED FROM CONSTRUCTED WETLAND SYSTEM
2006
A total of 174 actinomycete cultures were isolated from a constructed biological water treatment system (BIOWATSYST)established at Abu Attwa station in Ismailia city, Egypt and funded by the European Commission Grant No.IC18-CT97-0163. The isolates were identified to belong to eight genera; Nocardia, Streptomyces, Intrasporangium, Micromonospora, Nocardioides, Actinomadura, Nocardiopsis, and Thermomonospora. They were screened for their antibacterial, antifungal and cytotoxic activities against certain human and plant pathogens. Antimicrobial activities were determined by measuring bacterial and fungal growth inhibitions while cytotoxic activity was studied by using the Artemia salina bioassay. Thirty two percent of isolated cultures displayed antibacterial activity, 15% displayed antifungal activity and 9% displayed cytotoxic activity. Members of genus Streptomyces has recorded as the most frequent active isolates against tested bacteria (42%) and fungi (49%). However, the most cytotoxic activity was found with members of genus Nocardia (46%). Results evaluated the fact that actinomycetes isolated from such systems could be considered as promising source for antimicrobial and cytotoxic bioactive agents.
Показать больше [+] Меньше [-]EFFECT OF SOME SLOW RELEASE N FERTILIZERS ON GROWTH AND FRUITING OF TWO MANGO CVS; FIGRI KELAN AND KEITT
2006
A.Y. Mohamed | Sanaa S. Ebeed
This study was conducted for comparing three slow release N fertilizers namely, sulphur-coated urea (SCU), phosphorus – coated urea (PCU) and Enciabene with the conventional fast release N fertilizer namely ammonium nitrate each at the recommended rate of N i.e., 1000 g N/tree/year for growth characters on the three growth flushes, percentages of leaf N, P and K in the Spring growth cycle, date of first bloom, number of panicles/tree, fruit retention %, yield as well as physical and chemical characters of fruits in two mango cvs Figri Kelan and Keitt during 2004 and 2005 seasons. Results showed that suppling the trees of both mango cvs with the three slow release N fertilizers were superior to the application of the fast one in improving shoot length, number of leaves / shoot and leaf area in the three growth cycles, percentages of leaf N, number of panicles / tree as well as physical and chemical properies of the fruits. The slow release N fertilizers slightly advanced first bloom date. Application of sulphur-coated urea (SCU), phosphorus-coated urea (PCU) and Enciabene (ENC) in a descending order, was very favorable in this connection. These results were true for both mango cvs. It is suggested to fertilize the trees of both mango cvs Figri Kelan and Keitt with N at 1000g/tree/year as sulphur-coated urea fertilizer (2.4 Kg/tree/year) for obtaining an economical yield with fairly good fruit quality
Показать больше [+] Меньше [-]SYNERGISTIC EFFECT OF VOLATILE OILS AND ANTIBIOTICS AGAINST SOME GRAM POSITIVE AND NEGATIVE PATHOGENIC BACTERIA
2006
M.F. Ghaly
Eight most currently used antibiotics were examined for their antibacterial properties against Gram-ve bacteria as Pseudomonas aeuroginosa, E. coli, Proteus vulgari and Gram+ve as Staphylococcus aureus, Streptococcus pneumonia. Nitrofurantoin was the most effective against the tested bacteria, the inhibition zones ranged between 16-20mm and the MIC between 65-85ug/ml followed by ampicillin (11-18mm), ciprofloxacin (9-12mm) and gentamicin (6-9mm). The erythromycin was the lowest effective against the tested bacteria. Also, seven volatile oils were applied by contact and fumigation methods to study their effect on the tested bacterial strains. The fumigation method gave the highest inhibitory effect more than contact method and the thyme oil gave maximum inhibitory action (inhibition zone 20-28mm) against all the tested bacteria, and the MIC ranged between 0.1-0.15mg/ml followed by marjoram oil (19-25mm) and the MIC between 0.1-0.2mg/ml, cinnamon oil (12-16mm) and the MIC between 0.2-0.3mg/ml. Anise and chamomile oils did not gave any response against all the tested bacteria. The combination between thyme and other tested oils gave a synergistic effect for inhibitory action against all the tested bacteria, if compared with thyme oil alone. The combination between thyme and marjoram oil gave the maximum inhibition zones (20-29mm), followed by thyme with cinnamon oil (20-27mm), thyme with geranium gave (18-27mm), thyme with peppermint (17-27mm), thyme with chamomile (16-27mm) and thyme with anise oil (15-26mm). The combination of thyme oil with different tested antibiotics gave the lowest inhibitory effect than combination between thyme and other volatile oils against all the tested bacteria. The protein and DNA content of treated bacteria with thyme oil were increased by 38.46-47.37% and 34.26-46.94% respectivily, if compared by non-treated bacteria
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