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Because vanadium (V) is easily reduced to a cationic form within plant cells, data from resin-extraction of soil were analysed for evidence of interactions between V and the resin-extractable concentrations of magnesium (Mg) and calcium (Ca) on soybean seed yield. Three varieties, 9091, 9061 and 704, were grown over a 3-year period in a corn–soybean–wheat rotation. Surface soil samples (0–15 cm) were extracted with ion-exchange resins, extracts were analysed by inductively coupled plasma methods (ICP), and the results were regressed against seed yield using SAS PROC STEPWISE analysis using forward selection, backward elimination and maximum R2 routines. The seed yield of each variety showed a correlation with a unique set of resin-extractable concentrations of V, phosphorus (P), Mg and Ca, and the V:(V + P), Mg:(Mg + Ca), Mg:(Mg + 1000 V) and Ca:(Ca + 1000 V) ratios. Variety 9091 was most sensitive to the Mg:(Mg + Ca) ratio. Variety 9061 was most sensitive to extractable V and to the V:(V + P) ratio. Variety 704 was sensitive to extractable P, V and Ca and the Mg:(Mg + 1000 V) ratio. For variety 9091, Mg fertilization (not currently practised) may be an economical practice, whereas P fertilization of 704 may not be economical. Each regression technique varied slightly in identification of important factors in seed yield. Concentrations and ratios of resin-extractable elements in soil provide insights into optimal genotype selection and possible management alternatives for a given soil. 相似文献
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Carbon dioxide (CO2) can effectively separate hexane from a mixture of soybean oil (SBO) and hexane with a slight coextraction of SBO. Previous research demonstrated that CO2 entrained with helium significantly reduced SBO solubility in CO2. In this study, CO2 was mixed with three gases (He, N2, or Ar) (0.5-30 vol %) to decrease SBO solubility while attempting to maintain hexane solubility. The binary gas mixtures (at 25 degrees C and 9.31 MPa) were passed through a 25 wt % hexane/SBO mixture inside a 2.5 m fractionation column. Coextracted SBO was inversely proportional to binary gas concentration, whereas residual hexane in the raffinate was proportional to binary gas concentration. The 10% binary mixture of N2 or Ar was the best compromise to obtain both low residual hexane levels (i.e., 26 ppm) and low SBO coextraction (i.e., only 40 mg). This carry-over of SBO represents a 95% reduction in SBO carry-over compared to neat CO2. 相似文献
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Nine Prunus accessions were evaluated for germination and plantlet growth in an in vitro osmotic screening test using mannitol
as an osmoticum. Embryos from diverse peaches, almonds and peach-almond hybrids were cultured in Woody Plant Medium, and in
this same medium modified with the inclusion of 350 mM mannitol. Embryos were stratified in vitro for 60 days, induced to
germinate for a two week period and then allowed to develop and grow for another 20 days prior to harvest. Fresh weights of
both roots and shoots as well as percent germination were recorded at harvest. The main effects of nutrient medium, germplasm
type (peach, peach-almond, almond) and specific Prunus accession were all highly significant (P = 0.01) with regard to fresh
weight of roots and shoots. Embryo germination was affected significantly by the inclusion of mannitol in the nutrient medium
and by the particular germplasm type (P=0.01 and P=0.05, respectively). Significant interactions of nutrient medium × Prunus
accession and nutrient medium × germplasm type were also detected for both root and shoot fresh weights. Almond germplasm
cultured in Woody Plant Medium with 350 mM mannitol produced significantly more roots and shoots than either peaches or peach-almond
hybrids grown in the same medium. Peach-almond hybrid embryos were observed to germinate at a significantly higher frequency
than peach embryos when averaged across both media. Results obtained in this study indicate a wide range of average plantlet
fresh weight relative to the specific germplasm challenged in the osmotic screen.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Steven F. Vaughn Nathan A. DeppeDebra E. Palmquist Mark A. Berhow 《Industrial Crops and Products》2011,33(2):514-517
Soilless substrates are primarily used in the production of containerized greenhouse and nursery crops. Sphagnum peat moss is a primary constituent of these substrates and its harvest from endangered ecosystems has become a worldwide concern. Ethanol-extracted, coarse-ground corn (Zea mays L. ‘Silver Queen’) tassels were used as a peat replacement for potting substrates. Replacing peat moss with increasing levels of ground tassel (up to 50%, v/v) elevated pH and electrical conductance, while having variable effects on substrate physical properties (bulk density, percent solids, air porosity, container capacity, and total porosity). Two identical greenhouse experiments separated by time were conducted using tomato (Solanum lycopersicum L. ‘Red Robin’) plants grown in 6.0-L pots. In the first experiment, all substrates were similar for total tomato yield per plant and number of fruit per plant, with only the 50% tassel substrate having significantly lower values. There were no differences for plant height or average fruit weight among substrates. No differences were found for any of these variables in the second experiment. This research indicates that extracted ground tassels may be utilized as a suitable replacement for peat in greenhouse substrates for tomatoes. 相似文献
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Phospholipids and wheat gluten blends: interaction and kinetics 总被引：1，自引：0，他引：1
Abdellatif Mohamed S.H. Gordon Rogers E. Harry-O'Kuru Debra E. Palmquist 《Journal of Cereal Science》2005,41(3):259-265
A model system comprising of lysophosphatidylcholine (LPC) and isolated gluten were used help understand the positive effect of PL on bread-loaf volume. The kinetics of the effect of gluten on the thermal properties of LPC were determined using DSC. Blends of PL and 3, 6, and 10% gluten were heated from 0 to 70 °C at rates between 3 and 19 °C/min and cooled to 0 °C. The onset and peak temperatures and ΔH were recorded. The peak temperature was used to calculate the activation energy (Ea) and Z value. The transition for pure LPC vesicle formation was detectable by DSC in the presence of gluten. Gluten increased the activation energy of LPC during vesicle formation and disruption. The increase in gluten content from 3 to 6% and then to 10% had a slight effect on the activation energy value of LPC during vesicle disruption, whereas during formation a steady increase was noticed with higher gluten additions. Overall, the ΔH of the blends showed a decrease at higher heating rate. The change in the PL activation energy in the presence of gluten is indicative of a form of interaction. 相似文献
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Challenges with fats and fatty acid methods 总被引：5，自引：0，他引：5
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Palmquist R 《Journal of the American Veterinary Medical Association》2003,222(8):1072-3; author reply 1073
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Holstein male calves were maintained on conventional (milk to 6 wk of age, fed grain and hay after weaning) and veal (milk replacer only) diets to 16 wk of age. Within each of these 2 physiological states (ruminating or non-ruminating), calves were fed low or high fat diets (ruminating: 3 and 10%; veal: 10 and 18%). Glucose tolerance tests were undertaken at 8 and 16 wk of age in each group. Basal concentrations (4 hr postfeeding) and areas under the response curves for plasma glucose and insulin were higher in veal calves (P < .0001). Ruminating calves fed higher fat utilized glucose more readily (smaller areas under the curves for both glucose and insulin, P < .10) than those fed lower fat. Age did not influence basal glucose concentrations (P > .10), but older calves had higher basal insulin (P < .0001) and greater areas under the curves (P < .0005) for both glucose and insulin after a glucose challenge. Rate of clearance (k) was greater in ruminating calves (P < .001). Though rate of clearance in veal calves was slower, larger plasma pool size caused veal calves on average to utilize glucose at a 15% greater rate per kg body weight than ruminating calves. Whereas fat concentration in the diets did not influence glucose metabolism in veal calves, the high lactose content (> 50% of diet dry matter) of veal diets induced severe insulin resistance in these calves. 相似文献