Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses     

D. A. Bond  G. J. Jellis  G. G. Rowland  J. Le Guen  L. D. Robertson  S. A. Khalil  L. Li-Juan 《Euphytica》1993,73(1-2):151-166

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.  相似文献   

Carbonyl sulfide and carbon disulfide from the eruptions of mount st. Helens     

Rasmussen RA  Khalil MA  Dalluge RW  Penkett SA  Jones B 《Science (New York, N.Y.)》1982,215(4533):665-667

Ash from the massive 18 May 1980 eruption of Mount St. Helens readily gave off large amounts of carbonyl sulfide and carbon disulfide gases at room temperature. These findings suggest that the sulfur that enhances the Junge sulfate layer in the stratosphere after volcanic eruptions could be carried directly to the upper atmosphere as carbonyl sulfide and carbon disulfide adsorbed on ash particles from major volcanic eruptions.  相似文献   

Chemical stratification in the Seneca/Oswego rivers (NY)     

Steven W. Effler  James M. McCarthy  Karl W. Simpson  F. Joseph Unangst  GAry C. Schafran  William D. Schecher  Peter Jaran  Hsi-Sheng A. Shu  Magdy T. Khalil 《Water, air, and soil pollution》1984,21(1-4):335-350

The occurrence and characteristics of chemically-based density stratification in portions of the Seneca and Oswego Rivers, downstream of ion-polluted Onondaga Lake, are described for seven different days in the summer and fall of 1978 and 1981, which covered a wide range of river flows. The results indicate that chemically-based density stratification occurs routinely in the Seneca River downstream of the lake inflow, in response to a continuous chemically-based density difference between the two systems of 0.0015 to 0.0030 g cm^?3. The persistence of the phenomenon, and therefore the longitudinal range over which the river stratification occurred, was dependent on the velocity of river flow and the magnitude of the density gradient that bordered the upper river water and the lower released lake water. During the low flows common to summer the stratification extended approximately 14 km downstream to a dam, and 3 km upstream, of the lake outlet — river junction. Vertical mixing between the stratified layers increased as the flow in the Seneca River increased, and as the vertical density gradient decreased. A dimensionless group, $$\frac{D}{{V\left( {\frac{\rho }{{\Delta _\rho /\Delta _z }}} \right)}}$$ where: D = apparent vertical diffusion (m² hr^?1), V = average velocity of the overlying river flow (m hr^?1 ), p = density at the interface between the stratified layers (g cm^?3), and Ap/Az = density gradient between the stratified layers (g cm^?3 m^?1), was found to be constant for summer low flow conditions for a 6.5 km length of the Seneca River, thus quantifying the interaction between vertical mixing and the included influences for that portion of the river. The occurrence of chemical stratification in the river had dramatic implications on the corresponding distribution of dissolved oxygen (DO). The isolation of the organically enriched lake water in the lower layer enhanced the depletion of DO there, which resulted in the development of substantial (> 4.0 mg 1^?1 ) DO stratification downstream of the discharge from the lake during summer low flow periods.  相似文献   

Laboratory Observations Regarding Different Instars ofCyclosain-sulana (Costa, 1834) (Araneidae) During Developmental Stages     

Muhammad Saleem Khan  Muhammad Saleem Asghar  Iram Maqsood  Mohsin Bukhari  Lemeng Han  Tang Li-jie  Li Yi-jing  Shahla A  Khalil U R 《东北农业大学学报(英文版)》2015,(2):52-59

The current experiment was conducted to find out the optimal conditions for mass rearing and developmental changes of Cyclosainsulana. The lab. conditions were maintained at(27±2)℃ and(65±5)% RH. The clear perplex cages and natural diet consisting of the aphids, larvae of the house fly and larvae of drosophila were used for rearing. C. insulana took(123.12±7.26) days to develop from eggs to adults passing through eight instars under prevailing vivo conditions. The eggs were greenish white in color with average size of 0.57 mm ±0.034. The eggs spent(7.52±1.64) days in emergence. Maximum number of spiderlings survived at the 5th instar(84%) and minimum at the 1st instar(34%). The measurements of different body parts including the total body length, cephalothorax and pedipalps of the both male and female C. insulana were done with the help of micrometer and presented as mean±SD. The measurements varied in the each developing instar. It was concluded that spiders were difficult to rear in the lab. conditions and each developing stage which was regarded as instars showed variations in size colors and body characteristics.  相似文献   

Repellency and toxicity of aromatic plant extracts against the mosquito Culex pipiens molestus (Diptera: Culicidae)   总被引：2，自引：0，他引：2  

Traboulsi AF  El-Haj S  Tueni M  Taoubi K  Nader NA  Mrad A 《Pest management science》2005,61(6):597-604

The insecticidal activities of essential oil extracts from leaves, flowers and roots of aromatic plants against fourth-instar larvae of the mosquito Culex pipiens molestus Forskal were determined. Extracts of Foeniculum vulgare Mill were the most toxic, followed by those of Ferula hermonis Boiss, Citrus sinensis Osbeck, Pinus pinea L, Laurus nobilis L and Eucalyptus spp with LC50 values of 24.5, 44.0, 60.0, 75.0, 117.0 and 120.0 mg litre(-1), respectively. Combination tests between the LC50 and the maximum sub-lethal concentration (MSLC) were determined. Over 20 major components were identified in extracts from each plant species tested. Five essential oils and nine pure components were studied for their repellency against mosquito bites. Terpineol and 1,8-cineole were the most effective against Culex pipiens molestus bites offering complete protection for 1.6 and 2 h, respectively.  相似文献   

Contribution of technic materials to the mobile fraction of metals in urban soils in Marrakech (Morocco)   总被引：5，自引：2，他引：3  

Hicham El Khalil  Christophe Schwartz  Ouafae Elhamiani  Jochen Kubiniok  Jean Louis Morel  Ali Boularbah 《Journal of Soils and Sediments》2008,8(1):17-22

Background, Aim and Scope  In urban areas, soils are often dramatically altered by anthropogenic activity and these modifications distinguish these soils (Anthrosols, Technosols) from those in natural systems. In urban environments, they receive considerable pollution from industry, traffic and refuse. Since contaminated soil particles can be easily inhaled or ingested, there is a potential transfer of toxic pollutants to humans. Risk assessment is essentially based on the determination of the total or mobile contents of pollutants in soils using chemical extractions. This approach could be improved by taking into consideration the bioavailable fractions of these toxic elements as measured by biotests. The coarse soil fraction usually neglected in analyses can nevertheless have an effect on the concentration of metals in the soil solution. This coarse fraction is made up of the natural materials and of technic materials constituting anthropogenic soils (plastic, paper, fabric, wood, bones, metallic elements and building materials). These materials have variable capacities to release or adsorb trace elements. Samples representative of different technic fraction components of Marrakech urban soils permit one to quantify their contribution to the enrichment of the soluble metal concentrations. Works are carried out to achieve partial extractions of metals from the three fractions (less than 2 mm, coarse natural and coarse technic) of selected urban soils in order to determine their contribution to the metal contamination of soils. Materials and Methods  Selected soils were collected from 9 sites according to a gradient of increasing anthropogenic influence from suburban to urban zones. Soils were air-dried, homogenized, and sieved (2 mm). The coarse fraction was sorted to separate the different technic materials and natural materials. Water extractions were run, on the natural, coarse fraction, on the complete technic fraction of the 9 soils and on average samples made of technic materials sorted out of 58 topsoils sampled from different sites in the city of Marrakech. Results  Results show that the percentage of the technic fraction increases while approaching the historic city center. It represented about 14% in the most anthropogenically disturbed soils. Along this gradient, soils changed progressively from Anthrosols to Technosols according to the WRB classification of urban and industrial soils. Analyses of metal contents showed that the fine fraction (<2 mm) mainly contributed to the metallic contamination of the water soluble fraction. The natural coarse fraction had the highest contribution to the copper release and was responsible for the release of all water-extractable copper in some soils. Concerning the technic fraction, it has a significant contribution essentially in the most anthropogenically disturbed soils as characterized by an elevated percentage of anthropogenic elements. The water extractable metal contents of average samples of these anthropogenic elements shows that elevated metal concentrations were released by bones, wood, plastic and fabric/paper. Discussion  This study concerns soils in urban areas, which are strongly impacted by human activities. Part of the soils can be classified as Anthrosols, profoundly impacted through the addition of organic materials from household wastes, irrigation, or cultivation. Other soils strongly impacted by human activities are Technosols dominated or strongly influenced by man-made materials. Technosols appear mostly in urban and industrial areas and are more likely to be contaminated than Anthrosols. The composition and heterogeneity of urban soils lead to modifications of the mobility and availability of pollutants depending on successive land-uses and on the composition of technic materials. The fine fraction offers a high transferring surface capacity, leading to a high mobilization of metals. The technic fraction contributes significantly to the metal release in the Technosols. This property can be explained by a reversible adsorption of metals on the organic matter. Conclusions  Results confirm that anthropogenic activity causes a wide spatial diversity of soil quality in the urban and suburban area. It introduces large amounts of technic materials in soils that could have an impact on the metal availability. It therefore acts on the metal bioavailability in the urban Technosols. Recommendations and Perspectives  These results show that it is necessary, in addition to the characterization of the fine particles, to take into account the contribution of the coarse fraction of the Technosols in the evaluation of risks of transfer of metals to the food chain.  相似文献   

Correction to: Factors affecting reproductive performance in dromedary camel herds in Saudi Arabia     

Ali  Ahmed  Derar  Derar  Alsharari  Abdulhadi  Alsharari  Assaf  Khalil  Rashid  Almundarij  Tariq I.  Alboti  Yaser  Al-Sobayil  Fahd 《Tropical animal health and production》2019,51(7):2115-2115

Tropical Animal Health and Production - This article was originally published with incorrect affiliation 1. The correction affiliation is presented below.  相似文献   

Single nucleotide polymorphisms in the growth hormone gene of Oreochromis niloticus and their association with growth performance          下载免费PDF全文

Suhaila Karim Khalil Jaser  Marco Aurélio Dessimoni Dias  Aline de Assis Lago  Rafael Vilhena Reis Neto  Alexandre Wagner Silva Hilsdorf 《Aquaculture Research》2017,48(12):5835-5845

Polymorphisms in the growth hormone (GH) gene that is associated with the growth rate of farmed fish have been the target of many breeding programmes. The present study aimed to identify single nucleotide polymorphisms (SNPs) in GH gene regions to evaluate the association of SNP variations with the growth rate of two Nile tilapia: Oreochromis niloticus (Linnaeus, 1758) strains. The targeted regions were amplified, sequenced, aligned and screened for the presence of SNPs; thereafter, performance tests were used to check for the association between SNPs and weight. Allele and genotype frequencies were estimated for each SNP and genotype. Genotype blocks or sets of SNP genotypes and frequencies were also estimated. Association between SNPs and growth rate was statistically evaluated using a univariate linear mixed model that included both fixed and random effects. A total of 10 SNPs were identified, nine in the proximal promoter and one located in the 5′ UTR, forming 10 genotype blocks. In all weight recordings, five genotype blocks were significantly associated with the highest weights. Single nucleotide polymorphisms 6‐10 were also found to be significantly associated with growth (p‐value < .05). Genotypes with higher additive genetic values for weight were identified in the Chitralada strain, suggesting a possible impact of these additive effects of the GH SNP genotype on the growth rate of Nile tilapia. These findings may be used as part of marker‐assisted selection in tilapia breeding programmes.  相似文献   

Characterization of the Carbohydrates of Nonreduced Glutenin Fractionated by Multistacking SDS-PAGE from Two Hard Red Spring Wheat Flours     

Elzbieta Gujska  Khalil Khan 《Cereal Chemistry》1999,76(2):198-203

Native (nonreduced) glutenin aggregates of two hard red spring wheat flours (Len of good quality and line 205 of poor quality) containing the same high molecular weight glutenin subunits (2*, 7+9, and 5+10) were investigated for the possibility of glycosylation. Glutenins isolated by pH-precipitation were separated and purified under nonreducing conditions into five different molecular weight species by multistacking SDS-PAGE and by transfer to polyvinylidene difluoride (PVDF) membranes by electroblotting. Carbohydrate compositions of the total glutenin fraction and of the different molecular weight glutenin species separated on the stacking gels (4–12% acrylamide) were determined. More total carbohydrates were found in the total glutenin of the line 205 flour (2.33%) than in that of the Len flour (1.87%), with glucose and xylose contributing to the greater total amount in line 205. However, the total glutenin of Len had approximately twice as much of the total of arabinose, mannose, and galactose as line 205 had. After purification by electrophoresis, smaller amounts of monosaccharides (glucose, xylose, arabinose, galactose, and mannose) in the different molecular species were detected. After electroblotting to PVDF membrane to increase purification, no arabinoxylans were found. Following extraction of glutenin from membranes, the β-elimination procedure in mild base under reducing conditions was used. In that procedure, the mono- or oligosaccharide side chains are released from the protein core, and the sugars originally involved in the protein-sugar linkage are reduced to the sugar alcohol. After derivatization (with trimethylsilyl), samples were analyzed by gas chromatography and mass spectrometry. Glucose, galactose, and a small amount of mannitol were found in most of the different glutenin aggregates, except that mannitol was not found in the 8% stacking gel glutenin fraction. The content of mannitol was greater in the higher molecular weight glutenin species at the 4 and 6% origins. These results support the hypothesis that the carbohydrates and protein in the glutenin macropolymer may be covalently linked.  相似文献   

Hepatotoxic responses of 4-nonylphenol on African catfish (<Emphasis Type="Italic">Clarias gariepinus</Emphasis>): antixoidant and histochemical biomarkers     

Mahmoud Abd-Elkareem  Nasser S. Abou Khalil  Alaa H. Sayed 《Fish physiology and biochemistry》2018,44(3):969-981

4-Nonylphenol (NP) toxicity in fish attracts much attention due to its ability in targeting several organs; however, the researches regarding its potential hepatotoxicity are conflicting and still require further investigation. Therefore, the objective of this study is to focus on this issue from the histophysiological point of view using NP intoxicated African catfish (Clarias gariepinus) as a model of hepatotoxicity. Twelve adult fish (6 per group) were divided into two groups; the first was considered as a control and the second was exposed to NP dissolved in water at a dose of 0.1 mg/kg BW for 3 weeks. A significant reduction in the hepatic alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase levels was observed in NP-exposed fish. Concerning the oxidant/antioxidant balance, a significant depletion in superoxide dismutase, catalase, and glutathione peroxidase was found along with a significant elevation in total peroxide and malondialdhyde. The histopathological examination of the hepatic tissues revealed that NP had marked hepatotoxic effects including hepatitis, centrilobular and focal hydropic and fatty degeneration, fatty change (steatosis), hepatic coagulative necrosis, and nuclear alterations in addition to apoptosis of hepatocytes and necrosis of endothelial cells. Depletion of the glycogen and increased in pigments (lipofuscin and hemosiderin) content in the hepatocytes were also recorded. Hemosiderosis and proliferation of the connective tissue around the blood vessels and branches of bile ducts and in the portal areas were also observed. In light of these findings, it was concluded that NP has a well-defined hepatotoxic impact paving the road towards other studies to investigate other detrimental cyto-physiological influences of this aquatic pollutant.  相似文献