116 research outputs found

    Seroprevalence of cytomegalovirus and rubella among pregnant women in western Sudan

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    <p>Abstract</p> <p>Background</p> <p>Maternal cytomegalovirus (CMV) and rubella infections have adverse neonatal outcomes. Basic epidemiological data concerning CMV and rubella is necessary for health planners and care providers.</p> <p>Methods</p> <p>A cross sectional study was conducted at El-Rahad hospital, Sudan to investigate seroprevalence of CMV and rubella infections and associated possible risk factors among pregnant women. Structured questionnaires were used to gather socio-demographic data and ELISA was used to detect CMV and rubella infections using IgG and IgM.</p> <p>Results</p> <p>Out of 231 pregnant women, 167 (72.2%) and 151 (65.3%) were CMV-IgG and rubella-IgG positive, respectively. Only 6 (2.5%) and 8 women (3.4%) were CMV-IgM and rubella-IgM positive, respectively. While, high parity (OR = 14.7, 95%CI = 1.7 - 123.6; <it>P </it>= 0.01] and illiteracy (OR = 3.0, CI = 1.4 - 6.5; <it>P </it>= 0.004) were significantly associated with seropostive CMV-IgG in multivariate analysis, none of the other obstetrical and medical characteristics were significantly associated with CMV or rubella infections.</p> <p>Conclusion</p> <p>CMV prevalence was 72.2% and rubella susceptibility among pregnant women was 34.6%. Rubella vaccine and routine screening for rubella and CMV should be introduced for pregnant women in this setting. Further research is needed.</p

    Comparing genomic expression patterns across plant species reveals highly diverged transcriptional dynamics in response to salt stress

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    BackgroundRice and barley are both members of Poaceae (grass family) but have a marked difference in salt tolerance. The molecular mechanism underlying this difference was previously unexplored. This study employs a comparative genomics approach to identify analogous and contrasting gene expression patterns between rice and barley.ResultsA hierarchical clustering approach identified several interesting expression trajectories among rice and barley genotypes. There were no major conserved expression patterns between the two species in response to salt stress. A wheat salt-stress dataset was queried for comparison with rice and barley. Roughly one-third of the salt-stress responses of barley were conserved with wheat while overlap between wheat and rice was minimal. These results demonstrate that, at transcriptome level, rice is strikingly different compared to the more closely related barley and wheat. This apparent lack of analogous transcriptional programs in response to salt stress is further highlighted through close examination of genes associated with root growth and development.ConclusionThe analysis provides support for the hypothesis that conservation of transcriptional signatures in response to environmental cues depends on the genetic similarity among the genotypes within a species, and on the phylogenetic distance between the species

    Gas film retention and underwater photosynthesis during field submergence of four contrasting rice genotypes

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    Floods can completely submerge some rice (Oryza sativa L.) fields. Leaves of rice have gas films that aid O(2) and CO(2) exchange under water. The present study explored the relationship between gas film persistence and underwater net photosynthesis (P(N)) as influenced by genotype and submergence duration. Four contrasting genotypes (FR13A, IR42, Swarna, and Swarna-Sub1) were submerged for 13 days in the field and leaf gas films, chlorophyll, and the capacity for underwater P(N) at near ambient and high CO(2) were assessed with time of submergence. At high CO(2) during the P(N) assay, all genotypes initially showed high rates of underwater P(N), and this rate was not affected by time of submergence in FR13A. This superior photosynthetic performance of FR13A was not evident in Swarna-Sub1 (carrying the SUB1 QTL) and the declines in underwater P(N) in both Swarna-Sub1 and Swarna were equal to that in IR42. At near ambient CO(2) concentration, underwater P(N) declined in all four genotypes and this corresponded with loss of leaf gas films with time of submergence. FR13A retained leaf gas films moderately longer than the other genotypes, but gas film retention was not linked to SUB1. Diverse rice germplasm should be screened for gas film persistence during submergence, as this trait could potentially increase carbohydrate status and internal aeration owing to increased underwater P(N), which contributes to submergence tolerance in rice

    Genome-wide association and high-resolution phenotyping link oryza sativa panicle traits to numerous trait-specific QTL clusters

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Rice panicle architecture is a key target of selection when breeding for yield and grain quality. However, panicle phenotypes are difficult to measure and susceptible to confounding during genetic mapping due to correlation with flowering and subpopulation structure. Here we quantify 49 panicle phenotypes in 242 tropical rice accessions with the imaging platform PANorama. Using flowering as a covariate, we conduct a genome-wide association study (GWAS), detect numerous subpopulation-specific associations, and dissect multi-trait peaks using panicle phenotype covariates. Ten candidate genes in pathways known to regulate plant architecture fall under GWAS peaks, half of which overlap with quantitative trait loci identified in an experimental population. This is the first study to assess inflorescence phenotypes of field-grown material using a high-resolution phenotyping platform. Herein, we establish a panicle morphocline for domesticated rice, propose a genetic model underlying complex panicle traits, and demonstrate subtle links between panicle size and yield performance.Rice panicle architecture is a key target of selection when breeding for yield and grain quality. However, panicle phenotypes are difficult to measure and susceptible to confounding during genetic mapping due to correlation with flowering and subpopulatio710527FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)2011/03110-

    Zn uptake, translocation and grain Zn loading in rice (Oryza sativa L.) genotypes selected for Zn deficiency tolerance and high grain Zn

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    Zn deficiency is a widespread problem in rice (Oryza sativa L.) grown under flooded conditions, limiting growth and grain Zn accumulation. Genotypes with Zn deficiency tolerance or high grain Zn have been identified in breeding programmes, but little is known about the physiological mechanisms conferring these traits. A protocol was developed for growing rice to maturity in agar nutrient solution (ANS), with optimum Zn-sufficient growth achieved at 1.5 μM ZnSO4.7H2O. The redox potential in ANS showed a decrease from +350 mV to −200 mV, mimicking the reduced conditions of flooded paddy soils. In subsequent experiments, rice genotypes contrasting for Zn deficiency tolerance and grain Zn were grown in ANS with sufficient and deficient Zn to assess differences in root uptake of Zn, root-to-shoot Zn translocation, and in the predominant sources of Zn accumulation in the grain. Zn efficiency of a genotype was highly influenced by root-to-shoot translocation of Zn and total Zn uptake. Translocation of Zn from root to shoot was more limiting at later growth stages than at the vegetative stage. Under Zn-sufficient conditions, continued root uptake during the grain-filling stage was the predominant source of grain Zn loading in rice, whereas, under Zn-deficient conditions, some genotypes demonstrated remobilization of Zn from shoot and root to grain in addition to root uptake. Understanding the mechanisms of grain Zn loading in rice is crucial in selecting high grain Zn donors for target-specific breeding and also to establish fertilizer and water management strategies for achieving high grain Z

    Array-based genotyping and expression analysis of barley cv. Maythorpe and Golden Promise

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    BACKGROUND: Golden Promise is a salt-tolerant spring barley closely related to Maythorpe. Salt tolerance in Golden Promise has been attributed to a single mutation at the Ari-e locus (on 5H) resulting from irradiation of Maythorpe. Golden Promise accumulates lower shoot Na(+ )compared to Maythorpe when growing under saline conditions. This study focused on elucidating the genetic basis and mechanisms involved in this difference. RESULTS: The level of polymorphism between the two genotypes was explored using the Barley1 GeneChip for single feature polymorphisms (SFPs) and an oligonucleotide pool assay for single nucleotide polymorphisms (SNPs). Polymorphism analyses revealed three haplotype blocks spanning 6.4 cM on chromosome 1H, 23.7 cM on chromosome 4H and 3.0 cM on 5H. The Barley1 GeneChip was used to examine transcript abundance in different tissues and stages during development. Several genes within the polymorphic haplotype blocks were differentially regulated. Additionally, a more global difference in the jasmonic acid pathway regulation was detected between the two genotypes. CONCLUSION: The results confirm that Golden Promise and Maythorpe are genetically very closely related but establish that they are not isogenic, as previously reported, due to three polymorphic haplotype blocks. Transcriptome analysis indicates that the response of the two genotypes to salinity stress is quite different. Additionally, the response to salinity stress in the roots and shoot tissue is strikingly different

    Knowledge of eggplant farmers on the proper use of pesticides in Khartoum State, Sudan

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    The knowledge of eggplant farmers on the proper use of pesticides was evaluated in Khartoum State. Questionnaire was distributed to farmers in North Nile Farms (NN), East Nile Farms (ENF), and West Nile Farms (WNF) to solicit information. Interviews and questionnaires revealed that there is a limited level of awareness among farmers. The majority (94%) of farmers did not abide by recommended disposal procedures, they only damage and bury the containers inside the farms. The majority of farmers (66%) were not aware of the safety period for any given product. The excessive use of pesticides in eggplant production and reliance only on pesticides as a pest management strategy calls for the implementation of IPM programs integrating the use of environmentally soft chemicals with other non-chemical control methods to manage pests and diseases. Safety periods should be carefully watched to reduce the level of residues in eggplant fruits below the acceptable level and to ensure sustainable and safe production

    Increasing Plant Tolerance to Drought Stress by Inoculation with Arbuscular Mycorrhizal Fungi

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    Abstract: The present study was aimed to evaluate the effects of Glomus mosseae in three levels of soil infestation (300, 600 and 900 spores pot -1 ) to improve tolerance of maize plants (Zea mays L.) for drought stress conditions with bearing in mind determine some plant growth parameters (PGP) and biochemical [plant height, stem length, root length, plant fresh wt., shoot dry wt., root dry wt., root/shoot ratio, plant chlorophyll content, soluble protein, proline in leaves and Phosphorus (P) uptake] in the presence or absence of G. mosseae. The result shown that the drought treatment causing decrease in values of almost PGP, except plant root dry weight, which was increased when comparing with well irrigation treatment. The plants treated by G. mossea were recorded a significant (P˂0.05) increase in all PGP comparing with untreated plants in both normal irrigation and drought stress. The highest PGP values were recorded when plant inoculated by 900 spores pot -1 . The water deficit treatment was caused a significant decrease in plant soluble protein by rate 29.34% comparing with plants that well irrigate by normal way. While the G. mossea treatments were caused increase in plant soluble protein by rate 13.33, 22.18 and 29.27% in the normal irrigation treatment, and by rate 24.89, 36.25 and45.17% in the drought treatment comparing with plant in soil free from mycorrhizae. On contrast the proline content in plant leaves was increased in drought treatment by rate 22% comparing with plant in well irrigation. The treatments with G. mossea causing decreased in plant proline by rate 28.88, 38.05 and 43.19% in the drought treatment respectively with three levels of soil infestation. The drought treatment caused decrease in plant P uptake by rate 72.09% comparing with well irrigation treatment. The inculcation by G. mosseae caused increased in plant P uptake by rate 42.66, 76.11 and 79.32% in normal irrigation treatments and 88.34, 93.58 and 94.91% in drought stress comparing with plant free mycorrhizal in both water treatments

    Detection and validation of single feature polymorphisms using RNA expression data from a rice genome array

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    <p>Abstract</p> <p>Background</p> <p>A large number of genetic variations have been identified in rice. Such variations must in many cases control phenotypic differences in abiotic stress tolerance and other traits. A single feature polymorphism (SFP) is an oligonucleotide array-based polymorphism which can be used for identification of SNPs or insertion/deletions (INDELs) for high throughput genotyping and high density mapping. Here we applied SFP markers to a lingering question about the source of salt tolerance in a particular rice recombinant inbred line (RIL) derived from a salt tolerant and salt sensitive parent.</p> <p>Results</p> <p>Expression data obtained by hybridizing RNA to an oligonucleotide array were analyzed using a statistical method called robustified projection pursuit (RPP). By applying the RPP method, a total of 1208 SFP probes were detected between two presumed parental genotypes (Pokkali and IR29) of a RIL population segregating for salt tolerance. We focused on the <it>Saltol </it>region, a major salt tolerance QTL. Analysis of FL478, a salt tolerant RIL, revealed a small (< 1 Mb) region carrying alleles from the presumed salt tolerant parent, flanked by alleles matching the salt sensitive parent IR29. Sequencing of putative SFP-containing amplicons from this region and other positions in the genome yielded a validation rate more than 95%.</p> <p>Conclusion</p> <p>Recombinant inbred line FL478 contains a small (< 1 Mb) segment from the salt tolerant parent in the <it>Saltol </it>region. The Affymetrix rice genome array provides a satisfactory platform for high resolution mapping in rice using RNA hybridization and the RPP method of SFP analysis.</p

    Seed pre-treatment in rice reduces damage, enhances carbohydrate mobilization and improves emergence and seedling establishment under flooded conditions

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    Priming rice seeds (soaking followed by drying) or soaking just before sowing improved emergence from flooded soil, reduced membrane damage from ROS and hastened carbohydrate mobilization. Most benefit was to lines with a superior ability to germinate in flooded soil even when untreated
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