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排序方式: 共有122条查询结果,搜索用时 15 毫秒
91.
Hodgson JM Morton LW Puddey IB Beilin LJ Croft KD 《Journal of agricultural and food chemistry》2000,48(6):2276-2280
Gallic acid is one of the main phenolic components of black tea. The objective of this study was to identify urinary gallic acid metabolites with potential for use as markers of black tea intake. In an initial study, nine compounds, assessed by using gas chromatography-mass spectrometry, were found to increase in concentration in urine after 3 cups of black tea over 3 h. A subsequent study employed a controlled crossover design in which 10 subjects consumed 5 cups per day of black tea or water for 4 weeks in random order. Twenty-four hour urine samples were collected at the end of each period. Of the 9 candidate compounds identified in the initial study, only 3 were present at higher concentrations in urine of all 10 subjects during tea-drinking in comparison to water-drinking periods. These compounds were identified as 4-O-methylgallic acid, 3-O-methylgallic acid, and 3, 4-O-dimethylgallic acid, all methyl ether derivatives of gallic acid. It is suggested that these compounds have the potential to be used as markers of black tea intake. 相似文献
92.
93.
Antisperm antibodies in repeat‐breeding cows: Frequency,detection and validation of threshold levels employing sperm immobilization,sperm agglutination and immunoperoxidase assay 下载免费PDF全文
SK Srivastava S Shinde SK Singh S Mehrotra MR Verma AK Singh S Nandi N Srivastava SK Singh TK Goswami SK Bhure H Kumar SK Ghosh 《Reproduction in domestic animals》2017,52(2):195-202
Antisperm antibodies have been found in repeat‐breeding(RB) cows, and those causing agglutination and/or immobilization of sperm are considered to be closely related to unexplained infertility. However, a standard protocol for identifying antisperm antibodies (ASA) in cattle is not validated. Therefore, an investigation was undertaken to evaluate sperm immobilization (SIT), sperm agglutination (SAT) and immunoperoxidase (IPT)assays for detection of ASA in serum and their respective threshold levels for confirmation. Animals (heifers, normally breeding, repeat‐breeding and pregnant animals) that were free from IBR, brucellosis and uterine infections (screened by clinical examination) were included in the study. Sperm agglutinating, sperm immobilizing and antisperm antibodies evaluated by respective assay were significantly higher (p < .05) in RB cows compared to other groups. The SIT assay was able to identify 61% of RB caused by ASA, more than those employing SAT and IPT. Furthermore, a dilution rate of 1:5 and 1:80 (confirms 59.0 and 57.0% RB+ve)were sufficient to diagnose ASA by SAT and IPT, respectively. Results indicate the presence of __12.6% clumped spermatozoa and __ 2.6%(cut‐off value) peroxidase‐positive spermatozoa at 1:5 and 1:80 dilutions diagnosed with SAT and IPT, respectively, may be considered as repeaters arising out of ASA. Furthermore, study also showed the presence of lower incidence of ASA positivity in other groups of animals (heifer<normal breeder<pregnant animals) compared to repeaters. Study results show that although IPT is more specific and accurate but SAT and SIT are comparatively simple and cost‐effective assays suitable for detecting ASA under field conditions and thus can be recommended for screening of repeaters. 相似文献
94.
采用地理纬度相似地区选育的、具有代表性的中、美大豆品种,在不同种植密度,施肥水平和种植地区条件下对大豆品种的适应性进行了比较研究.结果表明:在不同种植密度条件下美国俄亥俄州立大学选育的品种综合表现较好,都有较高的产量表现,对种植密度有较好的适应性;而辽宁省选育的品种大多产量较低,受种植密度影响较大,种植密度适应性较差.在磷酸二铵做种肥的条件下,美国俄亥俄州立大学选育的品种表现较好,对肥料的利用率较高;辽宁省选育的品种中,辽豆12号对施肥的反应较好,其它品种相对产量较低,肥力适应范围狭窄.美国俄亥俄州立大学选育的品种在不同地区种植平均产量均显著高于辽宁省选育的品种,两国品种对地区的适应性表现趋势一致,都是鞍山>沈阳>大连. 相似文献
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96.
Conventional and contemporary approaches for drought tolerance rice breeding: Progress and prospects
C Anilkumar Rameswar Prasad Sah Radha Beena Muhammed Azharudheen TP Awadesh Kumar Sasmita Behera NC Sunitha SK Pradhan KR Reshmi Raj Parameswaran C BC Marndi Anil Kumar Singh 《Plant Breeding》2023,142(4):418-438
Drought is becoming a major threat to rice farming across the globe owing to the depletion of water tables in rice-growing belts. Drought affects rice plants at multiple stages, causing damage at morphological and physio-biochemical levels, leading to severe losses that exceed losses from all other stresses. The amalgamation of conventional breeding methods with modern molecular biology tools and biometrical methods could help accelerate the genetic gain for drought tolerance in rice. Many drought-tolerance traits with genetic determinants have been identified and exploited for tolerance rice variety breeding. The integration of genome-wide association study and genomic selection tools with speed breeding shortened the breeding cycle and aided in rapid improvement of genetic gain. In this review, we emphasized the progress made through classical breeding as well as the limitations and usefulness of current genomic methods in improving drought tolerance. We briefly addressed methods for identifying genetic determinants for drought tolerance and deploying them through genomics-assisted breeding programmes to develop high-yielding drought-tolerant rice cultivars. 相似文献
97.
Virupaksh U Patil Vanishree G. Vinay Sagar SK Chakrabarti 《American Journal of Potato Research》2017,94(3):266-269
Fusarium sambucinum is one of the most important causal agents that not only cause the dry rot disease of potato tubers in fields and stores worldwide but also capable of producing secondary metabolites toxic for people and animals. Here we present the first draft genome sequence of the strain (F-4) estimated to be around appx. 42.0 Mb. The genome has 12,845 protein coding genes with more than 35,900 exons and gene density of 3.13 per 10Kb. F. sambucinum is evolutionary more close to the F. graminearum among the Fusarium species complex. The genome sequence represents a valuable resource for understanding the pathogenecity and virulence factors, and their evolution within the complex and highly plastic genus Fusarium. 相似文献
98.
The ability to quantitatively and spatially assess soil surface roughness is important in geomorphology and land degradation studies. This paper describes the results of an experiment designed to investigate whether hyperspectral directional reflectance factors can describe fine‐scale variations in soil surface roughness. A Canadian silt loam soil was sieved to an aggregate size range of 1–4.75 mm and exposed to five different artificial rainfall durations to produce soils displaying progressively decreasing levels of surface roughness. Each soil state was measured using a point laser profiling instrument at 2 mm spatial resolution, in order to provide information on the structure and spatial arrangement of soil particles. Hyperspectral directional reflectance factors were measured using an Analytical Spectral Devices FieldSpec Pro Spectroradiometer (range 350–2500 nm), at a range of measurement angles (θr=?60° to +60°) and illumination angle conditions (θi= 28°–74°). Directional reflectance factors varied with illumination and view angles, and with soil structure. Geostatistically‐derived indicators of soil surface roughness (sill variance) were regressed with directional reflectance factors. The results showed a strong relationship between directional reflectance and surface roughness (R2= 0.94 where θr=?60°, θi= 67°–74°). This fine‐scale quasi‐natural experiment allowed the control of slope, initial aggregate size and rainfall exposure, permitting an investigation into factors affecting a soil’s bidirectional reflectance response. This has highlighted the relationship between fine‐scale variations in surface roughness, illumination angle and reflectance response. The results show how the technique could provide a quantitative measure of surface roughness at fine spatial scales. 相似文献
99.
Genetic diversity in 90 Indian soybean cultivars was assessed using 45 SSR markers distributed on 20 soybean chromosomes. Forty-five SSR markers generated 232 alleles with an average of five alleles/locus. The observed frequencies of the 232 alleles ranged from 0.01 to 0.94 with an average of 0.19. The polymorphic information content (PIC) value of the SSR markers varied from 0.10 to 0.83 with an average of 0.61 and about 71% markers have a PIC value of >0.5. In this study, 54 rare alleles including 19 genotype specific alleles were also identified. The observed hetrozygosity for SSR markers ranged from 0 to 0.11 with a mean of 0.10. Cluster analysis grouped the 90 soybean cultivars into three major clusters and principal coordinates analysis (PCoA) results were similar to those of the cluster analysis. A combination of eight SSR markers successfully differentiated all 90 soybean cultivars. The population structure analysis distributed the 90 soybean genotypes into two populations with mean alpha (α) value of 0.1873. In AMOVA analysis, proportion of variation within population was high (88%), whereas only 12% occurred among populations. In cluster and structure analyses, most of the genotypes with similar pedigree were grouped together. Soybean cultivars DS228, MACS-13, LSb-1, Hardee, Improved Pelican, and Pusa-24 were the six most genetically distinct cultivars identified. The study reported a moderate genetic diversity in Indian soybean cultivars and findings would be useful to the soybean breeders in selecting genetically distinct parents for a soybean improvement program. 相似文献
100.
The ethics of animal-based research is a continuing area of debate, but ethical research protocols do not prevent scientific progress. In this paper, we argue that our current knowledge of the factors that affect reproductive processes provides researchers with a solid foundation upon which they can conduct more ethical research and simultaneously produce data of higher quality. We support this argument by showing how a deep understanding of the genetics, nutrition and temperament of our experimental animals can improve compliance with two of the '3 Rs', reduction and refinement, simply by offering better control over the variance in our experimental model. The outcome is a better experimental design, on both ethical and scientific grounds. 相似文献