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Stefano Pavan Zheng Zheng Mariya Borisova Petra van den Berg Concetta Lotti Claudio De Giovanni Pim Lindhout Hans de Jong Luigi Ricciardi Richard G. F. Visser Yuling Bai 《Euphytica》2008,162(1):91-98
The recessive gene ol-2 confers papilla-associated and race-non-specific resistance to tomato powdery mildew caused by Oidium neolycopersici. In order to facilitate marker assisted selection (MAS) in practical breeding programmes, we identified two simple sequence repeat (SSR) markers and one cleaved amplified polymorphic sequence (CAPS) marker which are linked to the resistance locus and co-dominantly inherited. Aiming to provide a base for ol-2 positional cloning, we used a large segregating F2 population to merge these markers with all the ol-2 linked amplified fragment length polymorphism (AFLP®) markers previously identified in an integrated genetic map. By screening a tomato bacterial artificial chromosome (BAC) library, we detected two BAC clones containing two expressed sequence tags (ESTs) homologous to the gene mlo, responsible for powdery mildew resistance in barley, as well as an ol-2-linked marker. Chromosomal mapping by Fluorescence in situ Hybridization (FISH) revealed major signals of the two BAC DNAs in the pericentromeric heterochromatin of the short arm of chromosome 4, in the same region where the ol-2 gene was previously mapped. The genetic and cytogenetic co-localisation between ol-2 and tomato mlo-homologue(s), in addition to the similarity of ol-2 and mlo resistances for both genetic and phytopathological characteristics, suggests that ol-2 is likely a mlo-homologue. Thus, a homology-based cloning approach could be more suitable than positional cloning for ol-2 isolation. 相似文献
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John KM Vijayan D Rahul PR Joshi SD Kumar RR Mandal AK 《Journal of agricultural and food chemistry》2006,54(8):2828-2831
An effort has been made to isolate individual catechin compounds from green tea leaves in their pure form by electrophoresis. In the present study total polyphenol extraction was carried out initially and estimated through spectrophotometric and HPLC methods. Extracted polyphenol was separated on 0.7% agarose gel and visualized at 360 nm. Fragmented individual compounds were gel eluted with methanol and confirmed as (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG) by HPLC. The method developed describes a suitable method for the isolation of valuable molecules in tea. 相似文献
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T. A. Borisova G. E. D'Souza D. Miller 《Aquaculture Economics & Management (Blackwell Science)》2013,17(1):73-98
Aquaculture industry development has been recognized to be an important step in improving a state's economy. However, local producers are facing significant competition from international, national, and other state producers. In this paper, the focus is on competition among local producers. The objective is to examine how interactions among industry participants determine prices and profitability of individual fish growers. The application involves the trout sector of the West Virginia aquaculture industry. Using a game theoretic framework, the Bertrand oligopoly model, and a combination of data from primary and secondary sources, price competition among producers is modeled under different supply and demand scenarios. Factors such as production volume and cost, location relative to market outlets, supply dependability, and proximity to other competitors and markets influence the profitability and competitive position of individual producers. Results also show that, as expected, the entrance of new growers results in a reduction of the sales price, and creates more favorable conditions for sales outlets. In contrast, the appearance of new sales outlets results in an expected increase in sales prices and producers' profits. Implications are derived for the West Virginia aquaculture industry and for other areas where an abundant natural resource base combined with a rapidly growing aquaculture industry are linked to a growing competition for markets and, hence, producer profitability and survival. 相似文献
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Brian Bennett Tatiana Borisova Anura Amarasinghe 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):331-345
ABSTRACT As adoption of genetic modification (GM) technologies grows, so do questions about consumer acceptance. While willingness to consume GM crop products has been studied extensively, similar studies of GM fish and seafood are lacking. Econometric analyses of U.S. survey data reveal that older, higher income, non African American males are most likely to consume GM fish and seafood. The results can contribute to our understanding of GM fish and seafood consumption decisions which, in turn, can be used to identify and exploit the niche market for GM fish products. 相似文献
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There have been few reports on the diversity and prevalence of parasitic fauna of the endangered Siberian tiger, which inhabits the territory of the Russian Far East. The present review attempts to summarize the information about the parasitic fauna of wild Siberian tigers, which includes 15 helminths and 3 protozoan species. The most prevalent parasitic species was found to be Toxocara cati, followed by Toxascaris leonina. Another commonly recorded Platyhelminth species is Paragonimus westermani, which causes a lethal infection of the lung parenchyma in Siberian tigers. However, the information about infections by this fluke in the Siberian tigers is scarce, although P. westermani infections pose a serious health hazard to tiger populations. The nematodes Aelurostrongylus abstrusus and Thominx aerophilus are found in Siberian tigers with an occurrence rate of 2.3% and 19%, respectively. The information on the parasitic infestations of captive populations of Siberian tigers is also presented along with the sources of infection and hazards for the wild tiger populations in their natural environment. 相似文献
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Novel composite nanofibrous materials of poly(vinylidene fluoride) (PVDF) or poly(vinylidene fluoride-cohexafluoropropylene) (PVDF-HFP) and ZnO nanoparticles were prepared by conjunction of electrospinning and electrospraying techniques. Simultaneous electrospinning of concentrated solution of PVDF or PVDF-HFP and electrospraying of suspension of ZnO in diluted PVDF or PVDF-HFP solution enable the preparation of materials consisting of fibers on which ZnO was deposited on the fibers’ surface (design type “on”). These fibrous materials were compared with materials consisting of PVDF or PVDF-HFP fibers in which ZnO was incorporated in the fibers (design type “in”) and which were obtained by one-pot electrospinning of a suspension of ZnO nanoparticles in concentrated PVDF or PVDF-HFP solution. The fiber morphology and the presence of ZnO “in” or “on” the fibers were observed by scanning electron microscopy (SEM) and by transmission electron microscopy (TEM). The effect of the used technique on the type, size and shape of the obtained structures was discussed. The fibrous mats were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), contact angle measurements and mechanical tests as well. It was found that the decoration of fibers with ZnO resulted in increase of their thermal stability and hydrophobicity. The microbiological tests showed that the materials of design type “on” possessed strong antibacterial activity against the pathogenic microorganism Staphylococcus aureus. The results suggest that, due to their antibacterial activity, the obtained composite materials are suitable for wound dressing applications. 相似文献
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Regularities of the moisture regime of soddy-podzolic soils in Moscow Meshchera region under the impact of different surface planning operations were studied in the recreational zone. Soil moisture was determined in the samples taken with an auger. Data on the dynamics of soil moisture in 2014–2016 under different surface conditions—natural and artificial covers (backfill, mulching materials, and paving elements)— were obtained. A reliable (at the level of significance α = 0.05) increase in the soil water content in the 1-m-deep layer was observed on average for all years of research in three experimental variants: a “dry creek” cover with a possible additional inflow of water, mulching of a flat soil surface with shell rock, and mulching with pine needles. The increase in the soil water reserves on these plots reached 31.4, 22.5, and 19.4% in comparison with the control, where the average soil water reserves did not exceed 112 mm of the water layer and were close to the water content at 0.7 of the field water capacity (108 mm of the water layer). In comparison with the control, the unsealed areas of the soil within the rockery and within the paved surface were characterized by the decrease in the water storage by 4.0 and 11.2–30.7% during relatively wet and dry years, respectively. In wet years, this difference was statistically insignificant; in dry years, it was significant. The analysis of chronoisopleths of soil moisture attested to differentiation of the studied variants according to the degree of moistening of the soil profiles. 相似文献