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101.
102.
“Golden Rice” has played a key role in arguments over genetically modified (GM) crops for many years. It is routinely depicted as a generic GM vitamin tablet in a generic plant bound for the global South. But the release of Golden Rice is on the horizon only in the Philippines, a country with a storied history and complicated present, and contested future for rice production and consumption. The present paper corrects this blinkered view of Golden Rice through an analysis of three distinctive “rice worlds” of the Philippines: Green Revolution rice developed at the International Rice Research Institute (IRRI) in the 1960s, Golden Rice currently being bred at IRRI, and a scheme to promote and export traditional “heirloom” landrace rice. More than mere seed types, these rices are at the centers of separate “rice worlds” with distinctive concepts of what the crop should be and how it should be produced. In contrast to the common productivist framework for comparing types of rice, this paper compares the rice worlds on the basis of geographical embeddedness, or the extent to which local agroecological context is valorized or nullified in the crop’s construction. The Green Revolution spread generic, disembedded high-input seeds to replace locally adapted landraces as well as peasant attitudes and practices associated with them. The disembeddedness of Golden Rice that boosts its value as a public relations vehicle has also been the main impediment in it reaching farmers’ fields, as it has proved difficult to breed into varieties that grow well specifically in the Philippines. Finally, and somewhat ironically, IRRI has recently undertaken research and promotion of heirloom seeds in collaboration with the export scheme. 相似文献
103.
A survey of 24 wild Oryza accessions identified Oryza australiensis and Oryza rufipogon as potential sources of enhanced photosynthetic rate for introgression into cultivated rice. Photosynthetic capacity per unit leaf area (CER) was associated with leaf N content but not with leaf chlorophyll concentration, flag leaf area, or specific leaf area. Eight fertile, perennial F1 hybrids between O. sativa and O. rufipogon were grown in non-flooded soil, and CER was measured at flowering under saturating light. Two F1 hybrids had greater CER than the average of 26.1 μmol m2 s−1. The F2 progeny from these hybrids were screened for CER in the field, and segregants with even greater rates of photosynthesis were selected. The basis of high photosynthetic rate in the F2 populations was not leaf thickness or leaf chlorophyll content. One F2 line had exceptionally high CER and stomatal conductance. Broad-sense heritability on an individual plant basis for CER in two F2 populations was 0.44 and 0.37. A highly significant offspring-parent regression of 0.89 for CER was observed in a replicated field evaluation (four blocks, five plants per plot) of 20 vegetatively propagated F2 selections and their F3 seedling progeny. Broad-sense heritability for CER on a plot-mean basis was estimated as 0.74 for both selected F2:3 families and for the selected F2 clones. Genetic resources in the genus Oryza may represent a source of alleles to increase leaf photosynthetic rate in the cultivated species, which we have demonstrated to be a heritable, though environmentally variable, trait in an O. sativa/O. rufipogon population. 相似文献
104.
Harrigan GG Stork LG Riordan SG Reynolds TL Ridley WP Masucci JD Macisaac S Halls SC Orth R Smith RG Wen L Brown WE Welsch M Riley R McFarland D Pandravada A Glenn KC 《Journal of agricultural and food chemistry》2007,55(15):6177-6185
The Organization for Economic Co-operation and Development (OECD) recommends the measurement of specific plant components for compositional assessments of new biotechnology-derived crops. These components include proximates, nutrients, antinutrients, and certain crop-specific secondary metabolites. A considerable literature on the natural variability of these components in conventional and biotechnology-derived crops now exists. Yet the OECD consensus also suggests measurements of any metabolites that may be directly associated with a newly introduced trait. Therefore, steps have been initiated to assess natural variation in metabolites not typically included in the OECD consensus but which might reasonably be expected to be affected by new traits addressing, for example, nutritional enhancement or improved stress tolerance. The compositional study reported here extended across a diverse genetic range of maize hybrids derived from 48 inbreds crossed against two different testers. These were grown at three different, but geographically similar, locations in the United States. In addition to OECD analytes such as proximates, total amino acids and free fatty acids, the levels of free amino acids, sugars, organic acids, and selected stress metabolites in harvested grain were assessed. The major free amino acids identified were asparagine, aspartate, glutamate, and proline. The major sugars were sucrose, glucose, and fructose. The most predominant organic acid was citric acid, with only minor amounts of other organic acids detected. The impact of genetic background and location was assessed for all components. Overall, natural variation in free amino acids, sugars, and organic acids appeared to be markedly higher than that observed for the OECD analytes. 相似文献
105.
Glenn GM Klamczynski AK Holtman KM Shey J Chiou BS Berrios J Wood D Orts WJ Imam SH 《Journal of agricultural and food chemistry》2007,55(10):3936-3943
A heat expansion process similar to that used for expanded bead polystyrene was used to expand starch-based compositions. Foam beads made by solvent extraction had the appearance of polystyrene beads but did not expand when heated due to an open-cell structure. Nonporous beads, pellets, or particles were made by extrusion or by drying and milling cooked starch slurries. The samples expanded into a low-density foam by heating 190-210 degrees C for more than 20 s at ambient pressures. Formulations containing starch (50-85%), sorbitol (5-15%), glycerol (4-12%), ethylene vinyl alcohol (EVAL, 5-15%), and water (10-20%) were studied. The bulk density was negatively correlated to sorbitol, glycerol, and water content. Increasing the EVAL content increased the bulk density, especially at concentrations higher than 15%. Poly(vinyl alcohol) (PVAL) increased the bulk density more than EVAL. The bulk density was lowest in samples made of wheat and potato starch as compared to corn starch. The expansion temperature for the starch pellets decreased more than 20 degrees C as the moisture content was increased from 10 to 25%. The addition of EVAL in the formulations decreased the equilibrium moisture content of the foam and reduced the water absorption during a 1 h soaking period. 相似文献
106.
Glenn W. Stratton 《Water, air, and soil pollution》1987,35(1-2):195-206
The effect of temperature on interactions between combinations of the solvent acetone and the fungicide captan was determined using the fungi Pythium uhimum, Sclerotinia homeocarpa, and Pestalotia sp. Seven concentrations of acetone, ranging from 0.1 to 3.0% (v/v), were interacted with four concentrations of captan, ranging from 1.0 to 10.0 ppm (mg L?1 ). This procedure was repeated at 15, 20, 25, and 30 °C using potato dextrose agar at pH 5.5. Acetone and captan interacted synergistically towards P. ultimum and S. homeocarpa, and antagonistically towards Pestalotia sp., regardless of the temperature. The exact temperature response was dependent upon both the captan level and culture used. As the temperature increased from 15 to 30 °C, the toxicity of captan decreased by up to 40% with P. ultimum, and from < 10 to 20 with S. homeocarpa and Pestalotia sp. With only a few exceptions, the magnitude of interactions observed generally decreased as the temperature was increased from 15 to 30 °C. This was most pronounced with P. ultimum. Generally, the lowest interaction magnitudes were recorded at 20 °C for P. ultimum, 20 to 25 °C for S. homeocarpa, and 30 °C for Pestalotia sp. The greatest interaction magnitudes were usually obtained at 15 or 30 °C with P. ultimum, 15 °C with S. homeocarpa, and 25 °C with Pestalotia sp. 相似文献
107.
A theoretical model describing the general interaction between atmospheric trace gases, such as S02, NH3, C02 and 02, chemical reactant gaseous product H2SO4 and hydrometeors containing NaCl is proposed to study a possible mechanism for HCl production in non-precipitating cloud and the determination of the pH value of cloud droplets. Four different cloud droplet distributions have been used to estimate the upper limit of the amount of gaseous HCl released into the atmosphere resulting from the evaporation of cloud droplets. It is shown that the acid production and the amount of HCl released depend on the following factors: (a) the temperature of the cloud; (b) the oxidation rates; (c) the ambient concentration of SO2, NH3, and H2SO4; (d) the life cycle of the cloud; and (e) the liquid content of the cloud. This proposed chemical model also predicts a pH value spectrum depending on the cloud droplet distribution. Field measurements for the dependence of pH value on particle size and spatial distribution of gaseous HCl are recommended. 相似文献
108.
Aaron J. Glenn Lawrence B. Flanagan Kamran H. Syed Peter J. Carlson 《Agricultural and Forest Meteorology》2006,140(1-4):115
Net ecosystem carbon dioxide exchange was measured in two contrasting peatlands in northern Alberta, Canada using the eddy covariance technique during the growing season (May–October). Sphagnum spp. made up approximately 66% of the total LAI (1.52 m2 m−2) at the poor fen and the total N content of Sphagnum capitula was 7.8 mg g−1 at the peak of the growing season. In contrast, the dominant plant species at the extreme-rich fen site, the perennial sedge, Carex lasiocarpa, accounted for approximately 60% of the total LAI (1.09 m2 m−2), and had leaf total N content of 19.3 mg g−1 at peak biomass. In addition, the peak aboveground biomass was higher at the poor fen (230.9 g m−2) than at the extreme-rich fen (157.1 g m−2). Both sites had maximum daily rates of net CO2 uptake of approximately 5 μmol m−2 s−1, and typical nighttime rates of CO2 loss of approximately 2 μmol m−2 s−1 during the peak of the growing season. Calculations of maximum photosynthetic and respiratory capacity were consistently higher at the extreme-rich fen. The poor fen was a net sink for CO2 during 4 of the 6 months (peaking at 44 g C m−2 in July), while only slight net losses of CO2 (3 g C m−2) occurred in May and September. In contrast, the extreme-rich fen was calculated to be a significant net sink for CO2 only during 2 months of the growing season (peaking at 30 g C m−2 in August), while significant net losses of CO2 occurred in May (8 g C m−2) and in October (13 g C m−2). The plant species at the poor fen site were active earlier and later in the growing season, while it took longer for C. lasiocarpa to develop leaf tissue, and leaf senescence and reduction in photosynthetic activity occurred earlier in the fall at the extreme-rich fen. When integrated over the 6-month growing season, the poor fen was a net sink (90 g C m−2) that was three times larger than the extreme-rich fen (31 g C m−2). The ratio of cumulative total ecosystem respiration to gross primary production was 0.7 at the poor fen and 0.9 at the extreme-rich fen. 相似文献
109.
110.
Campbell K Fodey T Flint J Danks C Danaher M O'Keeffe M Kennedy DG Elliott C 《Journal of agricultural and food chemistry》2007,55(6):2497-2503
Concentrations of the coccidiostat nicarbazin as low as 2 mg/kg in feed can result in violative drug residues arising in poultry liver. A lateral flow device (LFD) was developed for the detection of contaminating concentrations of nicarbazin following solvent extraction of poultry feeds. Test results, as determined by both visual and instrumental measurement, are available within minutes. For 22 feed samples, nicarbazin-free and fortified at 2 mg/kg, the % relative inhibition ranged from 0 to 45% and from 53 to 85%, respectively. Nicarbazin contamination at the critical concentration (2 mg/kg) can be determined in all cases providing the sampling is representative. A wide range of feed samples taken at a mill that incorporated nicarbazin into poultry feed were analyzed. Data generated for these samples by both the LFDs and a mass spectrometric method were compared, and a significant correlation was achieved. 相似文献