Showing papers by "Agriculture and Agri-Food Canada published in 1999"
TL;DR: In this paper, a modified version of the TBARS method was proposed for assessing the presence of malondialdehyde (MDA) and other non-MDA compounds absorbing at 532 nm.
Abstract: The occurrence of malondialdehyde (MDA), a secondary end product of the oxidation of polyunsatu- rated fatty acids, is considered a useful index of general lipid peroxidation A common method for measuring MDA, referred to as the thiobarbituric acid-reactive- substances (TBARS) assay, is to react it with thiobar- bituric acid (TBA) and record the absorbance at 532 nm However, many plants contain interfering compounds that also absorb at 532 nm, leading to overestimation of MDA values Extracts of plant tissues including purple eggplant (Solanum melongena L) fruit, carrot (Daucus carota L) roots, and spinach (Spinacia oleracea L) leaves were assessed for the presence of MDA and other non-MDA compounds absorbing at 532 nm A method described herein corrects for these interferences by subtracting the absorbance at 532 nm of a solution containing plant extract incubated without TBA from an identical solution containing TBA The reliability and eAciency of this spectrophotometric method was assessed by altering the relative ratios of exogenous MDA additions and/or extracts of red cabbage (Brassica oleracea L) leaves containing inter- fering compounds and then measuring MDA recovery Reliability was also validated through high-performance liquid chromatography and high-performance liquid chromatography-mass spectrometry techniques Results indicated that over 90% of exogenously added MDA could be recovered through the improved protocol If there were no corrections for interfering compounds, MDA equivalents were overestimated by up to 965% Interfering compounds were not detected in vegetables such as lettuce (Lactuca sativa L) and spinach which had low or negligible concentrations of anthocyanidin derivatives Comparisons between the TBARS method presented here and two currently accepted protocols indicated that the new modified method exhibits greater accuracy for quantifying TBA-MDA levels in tissues containing anthocyanins and/or other interfering com- pounds This modified protocol represents a facile and rapid method for assessment of lipid peroxidation in virtually all plant species that contain interfering com- pounds
3,090 citations
TL;DR: The increase observed in antioxidant capacity through postharvest phenolic synthesis and metabolism suggested that commercially feasible technologies may be developed to enhance the health functionality of small fruit crops.
Abstract: Fresh strawberries (Fragaria × ananassa Duch.), raspberries (Rubus idaeus Michx.), highbush blueberries (Vaccinium corymbosum L.), and lowbush blueberries (Vaccinium angustifolium Aiton) were stored at 0, 10, 20, and 30 °C for up to 8 days to determine the effects of storage temperature on whole fruit antioxidant capacity (as measured by the oxygen radical absorbing capacity assay, Cao et al., Clin. Chem. 1995, 41, 1738−1744) and total phenolic, anthocyanin, and ascorbate content. The four fruit varied markedly in their total antioxidant capacity, and antioxidant capacity was strongly correlated with the content of total phenolics (0.83) and anthocyanins (0.90). The antioxidant capacity of the two blueberry species was about 3-fold higher than either strawberries or raspberries. However, there was an increase in the antioxidant capacity of strawberries and raspberries during storage at temperatures >0 °C, which was accompanied by increases in anthocyanins in strawberries and increases in anthocyanins and ...
992 citations
TL;DR: While plant breeding and agronomic management can minimize soil–plant transfer of Cd, and maximize concentrations of antagonists to Cd assimilation in humans, it remains important that inputs of this metal to soil be minimized.
887 citations
TL;DR: Vicultural practices that increased cluster sun exposure generally led to higher phenolics and color density of wines, whereas changing yeasts used for fermentation had minimal effects.
Abstract: Changes in phenolics (anthocyanins, flavonols, tartaric esters, and total phenolics) during ripening of grapes and in phenolics and color during vinification and aging of Cabernet Franc, Merlot, and Pinot Noir wines were studied. Anthocyanins in grape skins showed variations in accumulation pattern, concentration, and distribution depending on variety and to a lesser extent on season. During vinification, colorless phenolics increased during alcoholic fermentation, reached maximum values at pressing, and remained stable during malolactic fermentation and subsequent storage. Anthocyanins and color density, on the other hand, increased during the early stages of alcoholic fermentation, reached maximum values 2-3 days after the start of fermentation, decreased during malolactic fermentation, and slowly declined during subsequent storage. Viticultural practices that increased cluster sun exposure generally led to higher phenolics and color density of wines, whereas changing yeasts used for fermentation had minimal effects.
592 citations
TL;DR: The general ecology, biology, life history, and available sources for identification of oribatid mites (including Astigmata), the most numerically dominant arachnid group in the organic horizons of most soils, are reviewed to evaluate their role for bioindication in agroecosystems.
397 citations
TL;DR: The manufacture of the main products derived from sea buckthorn is described, including several examples from the patent literature, to form a comprehensive source of information on the manufacture and composition of sea buckstorn products.
Abstract: Sea buckthorn (Hippophae rhamnoides) is a unique plant currently being domesticated. The fruit is the main component of value, although the leaves are occasionally made into sea buckthorn tea. The two main sources of valuable products are derived from the berries, juice from the fleshy tissue and seed as a single seed from each berry. The juice provides a nutritious beverage, high in suspended solids and very high in vitamin C and carotenes. The juice may contain an oil phase trapped within the suspended solids, or the oil may be removed as pulp oil and provided separately. The pulp remaining after juice removal provides for extraction of "sea buckthorn yellow", a pigment that has potential use as a food coloring material. The seed is a source of seed oil, which is very unsaturated and shows promise, because of its light absorption and emollient properties, as an ingredient in cosmetics, phytopharmaceuticals, or UV skin protectant preparations. It may be prepared by conventional extraction techniques or by supercritical carbon dioxide extraction. The manufacture of the main products derived from sea buckthorn is described, including several examples from the patent literature. The available compositional data for the main products are tabulated to form a comprehensive source of information on the manufacture and composition of sea buckthorn products.
319 citations
TL;DR: In this article, the effect of osmotic treatment, vacuum-drying, air drying, and air drying and their combination on the retention of lycopene bioactivity was investigated.
306 citations
TL;DR: In this paper, the authors reviewed a number of studies showing that farm animals handled roughly or aversively learn to associate the handling with people, and that this learned fear of people can have marked effects on production.
290 citations
TL;DR: The results demonstrated the benefits of using a fibrolytic enzyme additive to enhance feed digestion and milk production by dairy cows.
288 citations
TL;DR: Results suggest that chitosan controlled seed-borne F. graminearum infection and increased the resistance in seedlings by stimulating the accumulation of phenolics and lignin and has a potential for improvement of seed quality and enhancement of crop yields.
Abstract: Chitosan treatment (2-8 mg/mL) of wheat seeds significantly improved seed germination to recommended seed certification standards (>85%) and vigor at concentrations >4 mg/mL, in two cultivars of spring wheat (Norseman and Max), by controlling seed-borne Fusarium graminearum infection. The germination was 85% in benomyl- and chitosan-treated seeds. Seed-borne F. graminearum was reduced to >50% at higher chitosan treatments compared to the control. Synthesis of phenolic acids was stimulated in primary leaves following chitosan treatment, and levels of these phenolic acids, especially ferulic acid, increased significantly with increasing chitosan concentration. Lignin content of primary leaves also showed a similar pattern. The synthesis of precursors of lignin such as p-coumaric, ferulic, and sinapic acids and phenolic acids having antimicrobial activity such as benzoic, p-coumaric, caffeic, protocatechuic, chlorogenic, ferulic, and gallic acids was also stimulated by chitosan treatment. The induction of phenolic acids and lignin was significantly lower in cv. Max compared to Norseman. Chitosan also inhibited fungal transmission to the primary roots of germinating seedlings. Results suggest that chitosan controlled seed-borne F. graminearum infection and increased the resistance in seedlings by stimulating the accumulation of phenolics and lignin. Thus, chitosan has a potential for improvement of seed quality and enhancement of crop yields as well as increased value of stored grains for food and feed.
284 citations
TL;DR: Investigating effects of exogenous fibrolytic enzyme supplementation on dry matter intake, milk production, and digestibility in multiparous lactating Holstein cows in early lactation found it has the potential to enhance milk yield and nutrient digestibility of cows inEarly lactation without changing feed intake.
TL;DR: Cows recognized individual people, and the fear of people who are present during milking may reduce milk yield.
TL;DR: In a replicated 3 x 3 Latin square experiment, six heifers fed a 61% barley grain:39% alfalfa silage diet (DM basis) were given intraruminal doses of powdered Yucca schidigera (YS), with results likely resulted from a decreased concentration of protozoa and, presumably, from ammonia binding by YS.
Abstract: In a replicated 3 x 3 Latin square experiment, six heifers (443 +/- 6.1 kg) fed a 61% barley grain:39% alfalfa silage diet (DM basis) were given intraruminal doses of powdered Yucca schidigera (YS). Doses of 0 (control), 20, or 60 g/d were given at 0800 daily. Ruminal content was sampled 0, 2, 4, and 6 h after dosing. Acidity, concentrations of reducing sugars, free amino acids, and peptides in the rumen were not affected (P > .05) by YS. Relative to control, ruminal ammonia concentration was reduced (P .05) rate or extent of in situ DM degradability. Fibrolytic, amylolytic, and proteolytic activities in ruminal contents were similar among treatments (P > .05). Dry matter intake, apparent digestibilities of DM, NDF, and CP, nitrogen balance, and microbial protein synthesis in the rumen were not affected (P > .05) by treatment. The effect of YS on ruminal ammonia concentration likely resulted from a decreased concentration of protozoa and, presumably, from ammonia binding by YS. The effect on ruminal propionate was probably a result of a selective inhibitory effect of YS on rumen microbial species.
TL;DR: In this paper, the long-term effects of conventional tillage (CT) and no-tillage (NT) management of the predominantly small grain region of western Canada has been investigated.
Abstract: Improvement in soil quality to maintain high production and reduce negative environmental impacts is necessary for alternative crop production strategies to become socially acceptable and viable in the long-term. No-tillage (NT) management of the predominantly small grain region of western Canada has the potential to curb soil erosion and increase profitability. An understanding of the direct effects of NT on soil properties is necessary to evaluate its potential for sustained long-term productivity. We have compiled data collected from two sites in northern British Columbia to ascertain the long-term effects of conventional tillage (CT) and NT on soil components thought to be important in surface soil structural improvement. Soil water retention was greater under NT compared with CT without dramatically altering bulk density due to redistribution of pore size classes into more small pores and less large pores. Soil organic C was greater under NT than under CT nearest the soil surface. Water-stable aggregation improved under NT compared with CT, perhaps because more soil organic C was sequestered within macroaggregates under NT compared with CT that helped to stabilize these aggregates. Steady-state water infiltration was greater under NT than under CT as a result of soil structural improvements associated with surface residue accumulation and lack of soil disturbance. Barley (Hordeum vulgave L.) yield tended to be greater under NT than under CT in years of low rainfall as a result of improvements in soil water retention and transmission that may have provided a better environment for root development. Our data indicate that NT is a viable management strategy to improve soil quality in the cold, semiarid region of western Canada. This strategy could lead to high production, minimal negative environmental impacts, and a socially-acceptable farming system. # 1999 Elsevier Science B.V. All rights reserved.
TL;DR: Results suggest that acetate has the maximum molecular volume above which the film strength decreases very rapidly, which is essentially governed by the volume of thecounter ion and not by the interactions between this counter ion and the macromolecule.
TL;DR: In this article, the authors used measurements of the 13 C value of soil CO 2 to separate total soil respiration (R t ) into subeomponents R rh and R, in a maize field under undisturbed conditions and compared these R rh estimates with values obtained using the root exclusion approach.
Abstract: In presence of vegetation, the CO 2 -C produced by respiration activity in soils originates from plant C (rhizosphere respiration, R rh ) and from soil C (soil respiration, R s ). Quantitative estimates of the CO 2 produced by each source are required in many studies of C dynamics in the soil-plant system. In this study, we (i) used measurements of the 13 C value of soil CO 2 to separate total soil respiration (R t ) into subeomponents R rh and R, in a maize (Zea mays L.) field under undisturbed conditions and (ii) compared these R rh estimates with values obtained using the root-exclusion approach. The maximum contribution of R rh to total respiration was 45%, observed in August. Estimates of R rh increased from zero 30 d after planting to 2 g CO 2 -C m -2 d -1 70 d after planting, remained relatively constant at that level in August, and then decreased until the end of the growing season. The total C losses as R rh were 17% of the crop net assimilation. Estimates of R s gradually declined from 3.3 g CO 2 -C m -2 d -1 in late June to 1.4 g CO 2 -C m -2 d -1 at the end of the season. Losses of soil C represented 6% of total soil C. Variable values of δ 13 C of the soil CO 2 in the control plot after Day 250 made the technique less reliable late in the season. However, several observations indicated that the approach has potential to provide quantitative estimates of R rh and R,. First, the seasonal pattern of the R rh estimates coincided with that of the plant growth and physiological activity. Second, the cumulated R rh across the growing season agreed well with published data obtained using 14 C labeling techniques. Third, in the maize plot, variation in the estimated R, was closely correlated with changes in soil temperature with a Q 10 of 1.99 (r 2 = 0.87). Finally, the estimates of R rh obtained using the isotopic approach agreed well with those obtained using the root exclusion technique.
TL;DR: These studies suggest that genetic-based plant traits affect the distribution of many species and that the variation in hybrids can be used as tools to examine the genetic components of community structure and biodiversity.
Abstract: Plant hybrid zones are dynamic centers of ecological and evolutionary processes for plants and their associated communities. Studies in the wild and in gardens with synthetic crosses showed that hybrid eucalypts supported the greatest species richness and abundances of insect and fungal taxa. In an updated review of 152 case studies of taxa associated with diverse hybridizing systems, there were 43 (28%) cases of hybrids being more susceptible than their parent species, 7 (5%) resistant, 35 (23%) additive, 35 (23%) dominant, and 32 (21%) showed no response to hybridization. Thus, most taxa respond to hybrids in ways that result in equal or greater abundance, and hybrids tend to accumulate the taxa of their parent species. These studies suggest that genetic-based plant traits affect the distribution of many species and that the variation in hybrids can be used as tools to examine the genetic components of community structure and biodiversity. Several patterns have emerged thus far. (1) Genetic variation between classes of hybrids (e.g., F1’s vs. backcrosses) may equal or even exceed that found between species. (2) As a reflection of this genetic variation, herbivores are more likely to differentiate between hybrid classes than they are to differentiate between pure plant species. (3) The communities associated with different hybrid classes can differ from one another as well as from their parental species. (4) Generalist and specialist herbivores predictably vary in their responses to hybrids. (5) Plant hybrid zones may represent essential habitat for some arthropod species. (6) Even nesting birds respond to hybridizing plants. (7) Including multiple trophic levels and taxa from microbes to vertebrates, susceptible hybrid genotypes support greater biodiversity than resistant genotypes. (8) The effects of hybridization on common or keystone species can either positively or negatively affect biodiversity. The indirect impacts of hybridization on biodiversity may exceed the direct impacts and may result in “apparent” herbivore resistance or susceptibility at the community level. (9) Although hybrids are often maligned, exotic or problem hybrids generally result from human disturbances, whereas native hybrids are part of natural ecosystems and should be conserved.
Three predictions are made: (1) Intermediate genetic differences between the parental species will result in the greatest genetic variation in the hybrid zone, which in turn will have a positive effect on biodiversity. (2) Bidirectional introgression enhances species richness on hybrids, whereas F1 sterility and unidirectional introgression limit the accumulation of species on hybrids. (3) Although susceptible hybrids are likely to support the greatest biodiversity, the impacts of hybridization on keystone species will be crucial in determining the overall effect.
TL;DR: It is suggested that the trichothecenes may act as virulence factors to enhance the spread of F. graminearum on maize and appear less virulent on maize than the trICHothecene-producing progenitor and revertant strains, as assayed by most parameters.
Abstract: Trichothecene-producing and -nonproducing Fusarium graminearum strains were tested for their ability to cause Gibberella ear rot in field trials at two locations-Ottawa, Ontario, and Peoria, Illinois-in 1996. Maize ears were inoculated with wild-type or transgenic F. graminearum strains in which the trichothecene biosynthetic pathway had been disabled by the specific disruption of the trichodiene synthase gene and with a derivative revertant strain in which trichothecene production had been restored through recombination. A silk channel inoculation method was employed at both locations. In addition, a kernel puncture inoculation method was used at the Ontario location. Harvested maize ears were analyzed for visual disease severity, grain yield, deoxynivalenol (DON) concentration, and fungal biomass by quantitative polymerase chain reaction (PCR) and/or ergosterol quantitation. There was a significant correlation (r= 0.86) between data obtained from the two different methods of quantifying fungal biomass. The trichothecene-nonproducing strains were still pathogenic but appeared less virulent on maize than the trichothecene-producing progenitor and revertant strains, as assayed by most parameters. This suggests that the trichothecenes may act as virulence factors to enhance the spread of F. graminearum on maize.
TL;DR: The GFP is a useful marker in environmental microorganisms, allowing new research that will increase the understanding of microorganisms in the environment.
TL;DR: Results did not support the hypothesis that the administration of pLH or GnRH at known stages of the follicular wave in cycling heifers would consistently induce ovulation or atresia and, thereby, induce emergence of a new follicularWave at a predictable interval.
TL;DR: The results suggest for the MPS− mutant the involvement of the H+ pump mechanism in the solubilization of small amounts of phosphates and that the Mps+ phenotype was strongly associated with the production of gluconic or citric acids.
TL;DR: In this paper, various biological methods to sanitize sewage sludge and the efficiency and efficacy of these methods in eliminating pathogens and parasites are discussed, and a conceptual approach is presented on the basis of epidemiological and ecological studies in order to assess the environmental and health impacts of recycling sludge through land application.
Abstract: The agricultural utilization of sewage sludge imposes a high level of sanitation and stabilization of organic matter in order to maintain soil, water and air qualities and to effectively use such bioresidues as a soil amendment and as a source of nutrients for plants. Improper sanitation poses a serious threat to human and animal health. Stabilization and sanitation of sewage sludge have the advantage of coupling safe sewage sludge recycling in agriculture with its disposal, as many economic and environmental constraints make discharging strategies more and more difficult to apply. This article reviews the various biological methods to sanitize sewage sludge and the efficiency and efficacy of these methods in eliminating pathogens and parasites. Available monitoring techniques are also discussed. Finally, a conceptual approach is presented on the basis of epidemiological and ecological studies in order to assess the environmental and health impacts of recycling sewage sludge through land application.
TL;DR: In plants expressing Bcl-x(L), cell death induced by UV-B irradiation, paraquat treatment or the hypersensitive reaction to tobacco mosaic virus (TMV) infection was suppressed and enhanced resistance to cell death was found in transgenic tobacco plants overexpressing the ced-9 gene, indicating that Bcl(L) and Ced-9 can function to inhibit cell death in plants.
TL;DR: In this paper, the authors reviewed different indices that have been proposed to estimate the degree of soil P saturation and the relationships between soil saturation degree and P solubility. And they discussed their suitability as environmental indicators for P management in the province of Quebec, Canada, and proposed the ratio of Mehlich-III extractable P to Al (M3P/AlM3) as an alternative.
Abstract: Many agricultural fields contain excessive labile soil P in regard to crop needs. Its environmental fate must be assessed. The concept of P saturation degree is meaningful as it describes the portion of the soil binding sites already covered with P, and indicates the potential desorbability of soil P. The first objective of this study was to review different indices that have been proposed to estimate the degree of soil P saturation and the relationships between soil P saturation degree and P solubility. The second objective is to discuss their suitability as environmental indicators for P management in the province of Quebec, Canada. In the Netherlands, the P saturation index is defined as the ratio of P to Al + Fe contents extracted by ammonium oxalate [Pox/( Alox + Feox ) or ( Pox/0.5( Alox + Feox )]. This approach has been mainly used with non-calcareous soils. In Quebec, the ratio of Mehlich-III extractable P to Al (M3P/AlM3) is proposed as an alternative, which relies on routine laboratory test. How...
TL;DR: The application of the developed two step counterstaining treatment for the screening of phytase producing ruminal bacteria as well as its use inphytase zymogram assays are discussed.
TL;DR: The effect of hormic dosage of ultraviolet radiation in delaying the senescence of tomato was investigated in this paper, where mature-green tomato fruit (var. Capello) were irradiated with ultraviolet light (UV-C, 200-280 nm) corresponding to 0, UV-3.7×103 J m−2 and UV-24.4×103J m −2, and were stored at 16°C, under high relative humidity for a period of 35 days.
TL;DR: It is reported the production of a functional, purified anti-human IgG, through the expression of its encoding genes in perennial transgenic alfalfa, indicating that plant C5-1 could be used in a diagnostic reagent as effectively as hybridoma-derived C 5-1, and demonstrates the usefulness of perennial systems for the cost-effective, stable, and reliable production of large amounts of mAbs.
Abstract: The increasing use of monoclonal antibodies (mAbs) in diagnostic reagents necessitates efficient and cost-effective mAb production methods. In blood banks, one of the most routinely used reagents is the anti-human IgG reagent used for the detection of non-agglutinating antibodies. Here we report the production of a functional, purified anti-human IgG, through the expression of its encoding genes in perennial transgenic alfalfa. Transgenic plants expressing the light- and heavy-chain encoding mRNAs were obtained, and plants from crosses were found to express fully assembled C5-1. The purification procedure yielded mainly the H2L2 form with specificity and affinity identical to those of hybridoma-derived C5-1. The ability to accumulate the antibody was maintained both in parental F1 lines during repeated harvesting and in clonal material; the antibody was stable in the drying hay as in extracts made in pure water. Also, plant and hybridoma-derived C5-1 had similar in vivo half-lives in mice. These results indicate that plant C5-1 could be used in a diagnostic reagent as effectively as hybridoma-derived C5-1, and demonstrates the usefulness of perennial systems for the cost-effective, stable, and reliable production of large amounts of mAbs. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 64: 135–143, 1999.
TL;DR: Because the common soil fungus and mycoparasite GliCladium roseum differs from the type species of Gliocladium, G. penicillioides, in morphology, ecology, teleomorph, and DNA sequence data, it is considered a new type of soil fungus.
Abstract: Because the common soil fungus and mycoparasite Gliocladium roseum differs from the type species of Gliocladium, G. penicillioides, in morphology, ecology, teleomorph, and DNA sequence data, it is ...
TL;DR: Operating from one to six silver ion-high-performance liquid chromatography (Ag+-HPLC) columns in series progressively improved the resolution of the methyl esters of conjugated linoleic acid (CLA) isomeric mixtures from natural and commercial products.
Abstract: Operating from one to six silver ion-high-performance liquid chromatography (Ag+-HPLC) columns in series progressively improved the resolution of the methyl esters of conjugated linoleic acid (CLA) isomeric mixtures from natural and commercial products. In natural products, the 8 trans, 10 cis-octadecadienoic (18∶2) acid was resolved from the more abundant 7 trans, 9 cis-18∶2, and the 10 trans, 12 cis-18∶2 was separated from the major 9 cis, 11 trans-18∶2 peak. In addition, both 11 trans, 13 cis-18∶2 and 11 cis, 13 trans-18∶2 isomers were found in natural products and were separated; the presence of the latter, 11 cis, 13 trans-18∶2, was established in commercial CLA preparations. Three Ag+-HPLC columns in series appeared to be the best compromise to obtain satisfactory resolution of most CLA isomers found in natural products. A single Ag+-HPLC column in series with one of several normal-phase columns did not improve the resolution of CLA isomers as compared to that of the former alone. The 20∶2 conjugated fatty acid isomers 11 cis, 13 trans-20∶2 and 12 trans, 14 cis-20∶2, which were synthesized by alkali isomerization from 11 cis, 14 cis-20∶2, eluted in the same region of the Ag+-HPLC chromatogram just before the corresponding geometric CLA isomers. Therefore, CLA isomers will require isolation based on chain length prior to Ag+-HPLC separation. The positions of conjugated double bonds in 20∶2 and 18∶2 isomers were established by gas chromatography-electron ionization mass spectrometry as their 4,4-dimethyloxazoline derivatives. The double-bond geometry was determined by gas chromatography-direct deposition-Fourier transform infrared spectroscopy and by the Ag+-HPLC relative elution order.
TL;DR: Although the proportions of the five blueberry anthocyanidins varied substantially among the commercial blueberries, these differences probably do not contribute substantially to differences in their relative antioxidant capacity.
Abstract: Anthocyanins in ripe fruit of four Vaccinium species and genotypes within these species were compared, revealing substantial inter- and intra-species variability among these commercial and non-comm...