Уточнить поиск
Результаты 511-520 из 1,481
EFFECT OF TOOTH PICK (AMMI visnaga L.) SEED EXTRACTS ON THE RICE WEEVIL SITOPHILUS oryzae (COLEOPTERA : CURCULIONIDAE) Полный текст
2005
Salwa Ahmed | Nadra Al-Moajel
Seeds of the tooth pick plant (Ammi visnaga L.) were extracted by organic sol-vents of different polarities, and tested for their toxic effect on Sitophilus oryzae in-festing wheat grains. Toxicity of chloroform extract, was the most potent, at both Lc50 and Lc95 levels (i.e. 3240 and 8730 ppm). Reproductive potential of treated weevil were strongly affected as no progeny were obtained when treated with either Lc50 or Lc95 with A. visnaga. Extracts treatment at Lc95 level organic extract gave protection up to 12 weeks for petroleum ether and chloroform, and 9 weeks when acetone was used for extraction. All tested extracts reduced grain germination at the end of 14 weeks storage period. Also, treated wheat grains with tooth pick extracts reduced the weight loss of grains.
Показать больше [+] Меньше [-]MORPHOLOGICAL AND ANATOMICAL VARIATIONS OF ANABASIS ARTICULATA ECOTYPES IN EGYPT Полный текст
2005
Azza Khafagi | A. Marei | Sahar Mohamed
The present study has been carried out on ten stands of Anabasis articulata in Egypt. The relationships between the studied Anabasis articulata stands have been demonstrated as dendrogram based on the morphology, anatomy and some chemical constituents of the plants. Four characteristic ecotypes of Anabasis articulata have been recognized: (i) xerophytic ecotype in the stands of Belbase desert and Sudr El Hytat-Nekhl Road, (ii) xero - halophytiç ecotype in the stands of the Eastern Desert, Sinai Desert, Kattamia-Ain Sukhna Road, Isthmic desert (Fayid), Adabia and Saint Katherine, (iii) halophytic ecotype in the stands of the Red Sea Costal region, Ras Sudr and Hammam Faraon, Sinai and (iv) halo-xerophytic in the stands of the Nekhl-El Hasana and El Hasana-El Quseima Roads. These ecotypes differ, remark-ably, morphologically, anatomically and chemically. This may be due to the varia-tion in climatic and soil characteristics of the habitats
Показать больше [+] Меньше [-]CULTURAL, MORPHOLOGICAL, PHYSIOLOGICAL AND MOLECULAR STUDIES ON SOME STREPTOMYCETE ISOLATES Полный текст
2005
H Abdel-Fattah
In this study, three isolates of Streptomyces isolated from Egyptian soil at Giza Governorate and belonging to red series were identified based on their cultural, morphological and physiological characters. According to the key proposed by Pridham and Tresner (1974), the experimental isolates ST55, ST71 and ST86 ap-peared to be related to S. lincolnensis, S. venezuelae and S. umbrinus, respectively. In addition, random amplified polymorphic DNA (RAPD)-polymerase chain reac-tion (PCR) was used to amplify the DNA genome of the three applied isolates and an identified strain to determine their fingerprints. This was carried out using 10-decamer oligonucleotides, i.e., OP-A02, OP-D01, OP-D02, OP-D05, OP-D06, OP-D07, OP-D08, OP-D11, OP-D18 and OP-D20. The PCR amplified products were detected by electrophoresing on 1.5% agarose gel and visualized by staining in eth-idium bromide and UV trasilluminator. Results showed that the same oligonucleo-tide flanking fragments differed from one isolate to another with different sizes. Monomorphic and polymorphic fragments were amplified confirming the molecular relationships as well as the genetic diversity between the four applied strains of Streptomyces. Based on the statistical analysis of RAPD-PCR polymorphisms a de-gree of similarities ranged from 33.9 to 59.2 % was found. Furthermore, frag-ment(s), whatever absent or present, were found to be unique molecular markers and could be used for characterization of some isolates. This result supported the idea for using the RAPD-PCR technique for classification of Streptomyces isolates.
Показать больше [+] Меньше [-]CORRELATION AND PATH COFFICIENT ANALYSIS IN FOUR YELLOW MAIZE CROSSES UNDER TWO PLANTING DATES Полный текст
2005
K El-Shouny | Olfat El-Bagoury | K Ibrahim | S Al-Ahmad
F1 and F2 seeds of four crosses were formed during 2001 and 2002 growing sea-sons. The F2 population’s plants were evaluated during 2003 growing season under the two planting dates (14th May and 29th June) to estimate the phenotypic correla-tion coefficients among eight plants characters and their contributions in the varia-tion of grain yield/ plant at the Agric. Res. Stat. of Fac. of Agric., Ain Shams Univ., Shalakan, Kalubia Governorate, Egypt. Results showed that grain yield/ plant under normal planting date correlated positively and significantly - in most cases - with each of ear diameter, ear length, number of kernels/ row, 100-kernel weight, number of rows/ ear, ear height, plant height and days to silking, while under late planting date, it correlated with each of number of kernels/ row, ear diameter, 100-kernel weight, ear length, number of rows/ ear, ear height and days to silking. Path coeffi-cient analysis estimates indicated that ear diameter; ear length and number of ker-nels/ row can be considered as the most important sources of plant grain yield varia-tion under normal planting date while, under late planting date they were number of kernels/ row, ear diameter, 100-kernel weight and ear length. It was concluded that each of ear diameter, ear length and ear length through its indirect effects via ear di-ameter are considered as the most important sources of plant grain yield variation.
Показать больше [+] Меньше [-]QUALITY EVALUATION OF BEEF STEAKS WITH EDIBLE COATING DURING DEEP - FRYING Полный текст
2005
Nessrien Yasin | Hanan Al-Sayed | Salwa Abo-El-Fetoh
Quality of fried beef steaks coated with sodium alginate, carrageenan and car-boxy methyl cellulose (CMC) at concentrations 0.3, 0.6 and 0.9% as well as oils used for frying were evaluated after several frying times (1, 3, 5 and 7 times). Weight loss, shrinkage, moisture loss and final lipid content of control sample were sharply increased after the first time of frying compared to other treatments. The lower reduction in weight loss was achieved in fried beef steaks coated with CMC at concentration of 0.9%. Samples coated with 0.9% carrageenan caused a considerable decrease especially in shrinkage and moisture loss followed by samples coated with CMC and then those coated by sodium alginate at different concentrations. The same treatment (0.9% CMC) showed the lower value of final lipid content. There were significant (p<0.01) decremental patterns in all of sensory attributes (appear-ance, flavor, color, juiciness, mouth feel, texture and overall acceptability) of fried beef steaks during subsequent frying times for all treatments. Less rates of these de-terioration were appeared in CMC samples with different concentrations followed by samples coated with 0.3% and 0.6% of sodium alginate. Progressive rise in acid value of frying oils was especially found in control sample during different frying times, on the other hand the low rate of increase was appeared in sample coated with 0.3% and 0.6% sodium alginate. The higher values of K232 appeared in control sam-ple followed by 0.9% CMC but lower value recorded by oil used for frying beef steaks coated with 0.3% and 0.6% of sodium alginate after 5 times of frying. The same behavior was appeared in K270 determination except there was decrement pat-tern in this criteria by increasing frying times especially from 5 to 7 times of frying in control and coated samples with 0.3% and 0.6% of carrageenan. The highest val-ue of refractive index of fried oil was in control sample followed by coated sample with 0.9% sodium alginate after 7 times of frying. However, the lower value was in coated sample with 0.6% carrageenan under the same conditions. It is cleared to know that, the viscosity of oil which used for frying control sample was lower than that of other treatments during various frying times. Data revealed that the color in-dex (oil deterioration) increase as the concentration of different edible coatings of beef steaks and number of frying increased.
Показать больше [+] Меньше [-]PHYSIOLOGICAL EXPLORATION OF CERTAIN MAIZE INBRED LINES AND HYBRIDS BY USING RAPID METHODS TECHNIQUE 1. GENOTYPIC DIFFERENCES Полный текст
2005
M El-Koomy | A Abdel-Gawad | A. Abo-Shetaia | G Mahgoub
Identification of specific physiological differences among maize genotypes (six inbred lines, four single crosses and four three-way crosses) to drought would be useful to plant breeders for improving selection criteria. Two field experiments were conducted in optimum and stress moisture conditions at Gemmeiza Agricultural Re-search Station in 2001 and 2003 growing seasons. The treatments were 14 geno-types, (six inbreds and eight hybrids), which were separately established under three irrigation treatments in split plot design with four replications. The genotypes were compared under water-deficit conditions on the basis of certain rapid techniques to determine leaf area index (LAI), photosynthetic efficiency (photo), canopy tempera-ture depression (CTD), stomatal conductance (SC) and chlorophyll (CHL) content which were deleteriously affected by water stress in the sensitive genotypes. Results revealed that values of LAI, photosynthetic efficiency, canopy temperature depres-sion, stomatal conductance and chlorophyll content of maize hybrids surpassed those of inbred lines. This was true at 30, 45 and 60 days after planting (DAP). Dif-ferences among maize hybrids and among inbred lines were significant at different growth stages for the same studied traits, except of the LAI for the inbreds, at 30 DAP and CTD for the hybrids at 30 as well as 60 DAP. Detecting certain physio-logical criteria, i.e. LAI, photosynthetic efficiency (photo), canopy temperature de-pression (CTD), stomatal conductance (SC) and chlorophyll content (Chl) could be used as reliable techniques to explore the physiological activity of maize genotypes at early stages of growth and may be recommended in screening different genotypes in maize breeding programs.
Показать больше [+] Меньше [-]OCCURANCE OF LAYING WORKERS AT DIFFERENT HONEY BEE COLONIES STATUS Полный текст
2005
A Elbassiouny
Laying workers expressed as Workers with Activate Ovaries (WAO) having ma-ture oocytes had been studied in colonies headed with natural mated carnica queens. The results showed that the WAO were affected by the age of the queen, where it reached 0.8, 1.3 and 2.2 % for colonies headed with queens 10, 20 and 30 month old, respectively. The worker ovaries started to activate when the reached 22. 18 and 12 days from emergence for colonies headed with caged mated queens, caged virgin queens and queenless colonies, respectively. Also, when the worker's age reached 30 days, the percentages of WAO occurrence reached 3.3, 7.3 and 14.7 % for the corre-sponding colonies status, respectively. In preparing swarm boxes, when the bee-keepers failed to introduce the queens into the nuclei until two days, one week and two weeks, the WAO recorded 1.4, 4.8 and 9.2 %, respectively. In case of queen rearing, the presence of WAO was not significant until the fifth day, and then in-creased gradually to reach an average of 4.6% in the tenth day.
Показать больше [+] Меньше [-]INSECTICIDAL ACTIVITY AND BIOCHEMICAL STUDIES OF EGYPTIAN SESBAN, SESBANIA aegyptica ; JYNIT. SEED EXTRACTS AGAINST RICE WEEVIL, SITOPHILUS oryzae L. Полный текст
2005
Salwa Ahmed | Nadra Al-Moajel
The toxic effective of wheat grains treated with Egyptian sesban, Sesbania ae-gyptica seed extracts offered to rice weevil, Sitophilus oryzae was determined. Chlo-roform extract was found to be the most effective. Reproductive potential of treated weevil were strongly affected as number of laid eggs was reduced and no progeny were obtained when adults were fed on wheat grains treated with either Lc50 or Lc95 . Extracts treatment with Lc95 of extracts gave protection up to 10 weeks for petrole-um ether, and 9 weeks for both chloroform and acetone extracts. All tested extracts reduced grain germination at the end of 14 weeks storage period. Treated wheat grains with Egyptian Sesban seed extracts reduced the weight loss of grains infested with the rice weevil. Biochemical studies show that some enzymes were affected in treated insects. S. aegyptica acetone extract was more effective than the other ex-tracts, in this affect, as it caused a significant reduction in amylase, trehalse and acid phosphatase activity. However, this extract caused an increase in invertase, alkaline phosphatase and cholinestrase activity.
Показать больше [+] Меньше [-]Isolation and Characterization of Native Entomopathogenic Fungi and Their Pathogenicity Against Cowpea aphid Полный текст
2024
Alyaa Elsawy | mohamed elzemaity | Yosra Ahmed | Walaa Abdelghany
The research aimed to isolate and characterize local entomopathogenic fungi from different agricultural ecosystems and assess their pathogenicity against cowpea aphid. Forty soil samples were collected from different ecosystems. In total, 38 fungal isolates were collected from the cadavers' exteriors of Galleria mellonella larvae. Microscopic observation of these fungal isolates revealed that they belonged to nine fungal genera among them Metarhizium sp. (3 isolates) and Beauveria sp. (5 isolates). Primary experiments showed different bioactivities of the isolates of the two selected genera against the target insect. Only Metarhizium isolates (M3 & M5) and Beauveria isolates (B1 & B5) were selected for further investigations. Identification of fungal cultures by morphological characters, molecular characterization, ITS sequencing, and NCBI Blast showed that two isolates were confirmed as M. anisopliae and two isolates as B. bassiana. The bioassay evaluation revealed that M. anisopliae (M3 and M5) and B. bassiana (B1) exhibited significant virulence against A. craccivora, as evidenced by their high LT50 and LC50 values and substantial sporulation on the cadavers. Therefore, they could be used for the formulation of pesticides targeting this pest on cowpea and other vegetable crops.
Показать больше [+] Меньше [-]Effect of Calcium, Magnesium Fertigation and Molybdenum Foliar Sprays on Yield and Fruit Quality of Flame Seedless Table Grape Cultivar Полный текст
2024
Mohamed El-Katawy | Nazmy A Abdel Ghany | Mohamed Ibrahim | Ghobrial Ghobrial | Mohamed Abd El-Hamed Nasser
This investigation was performed during the 2018 and 2019 seasons in a private vineyard to study the effect of calcium, magnesium fertigation and molybdenum foliar sprays on the yield and fruit quality of Flame seedless table grape cultivar. The experimental layout was arranged in a split-plot design. All treatments were applied on three dates: after the bud burst stage, at the fruit set stage and veraison stage. The results showed that the combined application of 30 Kg calcium with 20 Kg magnesium fertigation and foliar spraying of 30 ppm molybdenum was the most effective among all treatments in terms of enhancing vegetative growth characteristics, increasing leaf content of total chlorophylls and mineral elements as well as improving yield and fruit quality attributes.
Показать больше [+] Меньше [-]