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101.
Heterosis is an important way to improve yield and quality for many crops. Hybrid rice and hybrid maize contributed to enhanced productivity which is essential to supply enough food for the increasing world population. The success of hybrid rice in China has led to a continuous interest in hybrid wheat, even when most research on hybrid wheat has been discontinued in other countries for various reasons including low heterosis and high seed production costs. The Timopheevii cytoplasmic male sterile system is ideal for producing hybrid wheat seeds when fertility restoration lines with strong fertility restoration ability are available. To develop PCR-based molecular markers for use in marker-assisted selection of fertility restorer lines, two F2 populations derived from crosses R18/ND36 and R9034/ND36 were used to map fertility restoration genes in the two elite fertility restorer lines (R-lines) R18 and R9034. Over 678 SSR markers were analyzed, and markers closely linked to fertility restoration genes were identified. Using SSR markers, a major fertility restoration gene, Rf3, was located on the 1B chromosome in both populations. This gene was partially dominant in conferring fertility restoration in the two restorer lines. SSR markers Xbarc207, Xgwm131, and Xbarc61 are close to this gene. These markers may be useful in marker-assisted selection of new restorer lines with T. timopheevii cytoplasm. Two minor QTL conferring fertility restoration were also identified on chromosomes 5A (in R18) and 7D (in R9034) in two R-lines.  相似文献   
102.
Disease prevalence studies are one of the most valuable tools to demonstrate the risk or impact of certain infections in local and global economies. The data obtained in these studies contribute to develop strategies for disease control. The present study aims to provide information about the prevalence of babesiosis and anaplasmosis in the northern regions of Sudan. Blood samples from four different states of Sudan were collected from apparently healthy cattle (n=692), DNA was extracted and the prevalence of Babesia and Anaplasma species was analyzed by PCR. The results confirmed the presence of Babesia bigemina, Babesia bovis and Anaplasma marginale in cattle in northern Sudan with overall prevalence rates of 4.0%, 1.9% and 6.1%, respectively. Statistical analysis revealed that the prevalence of B. bigemina, B. bovis and A. marginale varies significantly between Sudanese states as well as in different age groups, while gender seems not to have a significant effect on the prevalence of these pathogens among Sudanese cattle. The highest prevalence for B. bigemina was found in the Aljazirah State while the highest number of A. marginale positive samples was reported in River Nile.  相似文献   
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Tropical Animal Health and Production - The aim of this study was to replace fetal bovine serum (FBS) with platelet-rich plasma (PRP) for in vitro production of bovine embryos. The maturation media...  相似文献   
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The aim of this study was to assess the distribution of runs of homozygosity (ROH) and autozygosity islands in the composite Montana Tropical® beef cattle to explore hotspot regions which could better characterize the different biological types within the composite breed. Montana animals (n = 1,436) were genotyped with the GGP-LD BeadChip (~30,000 markers). ROH was identified in every individual using the plink v1.90 software. Medium and long ROH prevailed in the genome, which accounted for approximately 74% of all ROH detected. On an average, 2.0% of the genome was within ROH, agreeing with the pedigree-based inbreeding coefficient. The Montana cattle with a higher proportion of productive breed types showed the highest number of autozygosity islands (n = 17), followed by those with a higher proportion of breeds adapted to tropical environments (n = 15). Enriched terms (p < .05) associated with the immune and inflammatory response, homeostasis, reproduction, mineral absorption, and lipid metabolism were described within the autozygosity islands. In this regard, over-represented GO terms and KEGG pathways described in this population may play a key role in providing information to explore the genetic and biological mechanisms together with the genomic regions underlying each biological type that favoured their optimal performance ability in tropical and subtropical regions.  相似文献   
105.
Phylogeny is an evolutionary reconstruction of the past relationships of DNA or protein sequences and it can further be used as a tool to assess population structuring, genetic diversity and biogeographic patterns. In the microbial world, the concept that everything is everywhere is widely accepted. However, it is much debated whether microbes are easily dispersed globally or whether they, like many macro-organisms, have historical biogeographies. Biogeography can be defined as the science that documents the spatial and temporal distribution of a given taxa in the environment at local, regional and continental scales. Speciation, extinction and dispersal are proposed to explain the generation of biogeographic patterns. Cyanobacteria are a diverse group of microorganisms that inhabit a wide range of ecological niches and are well known for their toxic secondary metabolite production. Knowledge of the evolution and dispersal of these microorganisms is still limited, and further research to understand such topics is imperative. Here, we provide a compilation of the most relevant information regarding these issues to better understand the present state of the art as a platform for future studies, and we highlight examples of both phylogenetic and biogeographic studies in non-symbiotic cyanobacteria and cyanotoxins.  相似文献   
106.
We present a segmented partial least squares (PLS) prediction model for firmness of ‘Rocha’ pear (Pyrus communis L.) during fruit ripening under shelf-life conditions. Pears were collected from three different orchards. Orchard I provided the pears for model calibration and internal validation (set 1). These were transferred to shelf-life in the dark at 20 ± 2 °C and 70% RH, immediately after harvest. External validation was performed on the pears from the other two orchards (sets 2 and 3), which were stored under different conditions before shelf-life. Fruit was followed in the shelf-life period by visible/near infrared reflectance spectroscopy (Vis/NIRS) in the range 400–950 nm. The correlation between firmness and the reflectance at some wavelength bands was markedly different depending on ripening stage. A segmented partial least squares model was then constructed to predict firmness. This PLS model has two segments: (1) unripe and ripening/ripe pears (high firmness); (2) over-ripe pears (low firmness). The prediction is done in two steps. First, a full range model (full model) is applied. When the full model prediction gives a low firmness value, then the over-ripe model is applied to refine the prediction. The full model is reasonably significant in regression terms, robust, but allows only a coarse quantitative prediction (standard deviation ratio, SDR = 2.48, 1.50 and 2.40 for sets 1, 2 and 3, respectively). Also, RMSEP% = 139%, 91% and 56%, indicating large relative errors at low firmness values. The segmented model improved moderately the correlation, and the values of RMSEC, RMSEP and SDR; it improved significantly the RMSEP% (29%, 55% and 31%), providing an improvement of the relative prediction errors at low firmness values. This method improves the ordinary PLS models. Finally, we tested whether chlorophyll alone was enough for a predictive model for firmness, but the results showed that the absorption of chlorophyll alone does not explain the performance of the PLS models.  相似文献   
107.
This paper compares the responses of conventional and transgenic soybean to glyphosate application in terms of the contents of 17 detectable soluble amino acids in leaves, analyzed by HPLC and fluorescence detection. Glutamate, histidine, asparagine, arginine + alanine, glycine + threonine and isoleucine increased in conventional soybean leaves when compared to transgenic soybean leaves, whereas for other amino acids, no significant differences were recorded. Univariate analysis allowed us to make an approximate differentiation between conventional and transgenic lines, observing the changes of some variables by glyphosate application. In addition, by means of the multivariate analysis, using principal components analysis (PCA), cluster analysis (CA) and linear discriminant analysis (LDA) it was possible to identify and discriminate different groups based on the soybean genetic origin.  相似文献   
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This study investigated the in vivo genotoxicity of piquiá pulp (Caryocar villosum) and its potential antigenotoxicity on doxorubicin (DXR)-induced DNA damage by comet assay and micronucleus test. In addition, the phytochemicals present in piquiá pulp were determined. Piquiá fruit pulp (75, 150 or 300?mg/kg b.w.) was administered by gavage to Wistar rats for 14?days, and the animals received an injection of saline or DXR (15?mg/kg b.w., i.p.) 24 h before they were euthanized. The phytochemical analysis revealed the presence of carotenoids; phenolic compounds, including flavonoids; tannins and α-tocopherol in piquiá pulp. No statistically significant differences were observed in the evaluated parameters, demonstrating the absence of cytotoxic and genotoxic effects of piquiá pulp at all tested doses. In liver, kidney, cardiac and bone marrow cells, piquiá significantly reduced the DNA damage induced by DXR. Our results showed that the lowest piquiá dose caused the largest decrease in DNA damage and the highest dose caused the smallest decrease, demonstrating an inverse dose-response of piquiá pulp. Furthermore, we observed a difference in the potential antigenotoxic effects in several tissues. In conclusion, our results demonstrated that piquiá pulp was not genotoxic and inhibited the genotoxicity induced by DXR, but some of the protective effects that were observed depended on the doses and experimental conditions. Therefore, further investigations are needed to clarify how piquiá pulp positively affects human health.  相似文献   
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