Showing papers by "Agriculture and Agri-Food Canada published in 1982"
TL;DR: Initial experiments were undertaken to determine the virus susceptibility of early embryos, and no infectious virus was isolated from any of the embryos and the in vitro development of virus exposed embryos proceeded normally.
87 citations
TL;DR: The number of hydroxyl groups and their position relative to each other and the nature and position of other substituents on the aromatic ring were found to affect the activity of mono- and diphenols.
77 citations
TL;DR: Both the low level of the virus isolated from these embryos and the susceptibility of this virus to trypsin and antiserum suggests that IBRV attaches to the zona pellucida of embryos and cannot penetrate this structure to gain access to the embryonic cells.
58 citations
TL;DR: In this paper, a study was made of the weathering of trioctahedral, iron-rich, vermiculitic chlorite and diocta-hedral mica in a Spodosol (Haplorthod) developed on till derived from chlorite-mica schist.
53 citations
TL;DR: A new algorithm based on a polynomial function that is amenable to real-time weather acquisition and offers a practical alternative to the Stinner algorithm and other non-polynomial models for monitoring the development of insect pest populations.
Abstract: This paper discusses the various functions that have been used to predict the duration of insect life stages and presents a new algorithm for this purpose based on a polynomial function. The model was derived primarily for predicting biological events in the life history of the alfalfa weevil, Hypera postica (Gyll.), but gave equally precise simulations for three other species. Designed for a hand calculator, it is amenable to real-time weather acquisition and offers a practical alternative to the Stinner algorithm and other non-polynomial models for monitoring the development of insect pest populations.
52 citations
TL;DR: Although the SSD method had more opportunity for recombination than the DH method, it did not produce a sample of recombinants which differed significantly from the DH sample; thus both methods were equally efficient for use in deriving homozygous lines from F1 hybrids in a relatively short time.
Abstract: Both doubled haploid (DH) and single seed descent (SSD) methods were used to derive homozygous lines from two crosses of barley. The frequency distributions of grain yield, heading date, and plant height of the DH and SSD lines were compared by the Mann-Whitney U test, Kolmogorov-Smirnov twosample test and Wald-Wolfowitz runs test. It was found that the DH lines distributed in the same manner as the SSD lines with respect to the three characters. The results indicated that although the SSD method had more opportunity for recombination than the DH method, it did not produce a sample of recombinants which differed significantly from the DH sample; thus both methods were equally efficient for use in deriving homozygous lines from F1 hybrids in a relatively short time.
49 citations
TL;DR: The results indicated both stimulation and inhibition of O2 uptake by some organisms within these groups, and considerable effects of glyphosate on soil microorganisms.
Abstract: Limited information on the effect of glyphosate (N-phosphonomethylglycine) on soil microorganisms justified an inquiry into the response of soil actinomycetes, bacteria and fungi in terms of their respiration, and sensitivity of isolates. Low concentrations of glyphosate had little effect on total populations of these organisms during the 214-day experiment, while high concentrations initially increased actinomycete and bacterial numbers by 2 and 1 case1 2 logs, respectively. The stimulation was followed by a decline and fluctuation showing a gradual increase in numbers. The respiration rates of the soil microbiota in soil suspensions, showed some irregular stimulation and retardation with up to 10 μg glyphosate ml−1. In contrast high doses suppressed O2 uptake by the microbiota. Fungi were the least affected. Pronounced inhibition of actinomycete and bacterial respiration was in agreement with the results from isolate replication. The results indicated both stimulation and inhibition of O2 uptake by some organisms within these groups. In contrast to some reports of limited, short-term inquiries these results showed considerable effects of glyphosate on soil microorganisms.
46 citations
TL;DR: The bioconversion of waste paper to single-cell protein at pH <1 by Scytalidium acidophilum is described, and the chemical constituents and the essential amino acids of the fungal cells were similar to those of other fungi.
Abstract: The bioconversion of waste paper to single-cell protein at pH <1 by Scytalidium acidophilum is described. Waste paper pretreated with 72% H(2)SO(4) at 4 degrees C was diluted with water to a pH of <0.1 and hydrolyzed. This yielded an adequate sugar-containing substrate for the growth of the fungus. A total of 97% of the sugars (glucose, galactose, mannose, xylose, arabinose) in the hydrolysates were converted to cell biomass. Microbial contamination was not observed. Based on the sugars consumed, S. acidophilum produced higher yields in shake cultures than many other Fungi Imperfecti. In aerated cultures, productivity increased, and yields of 43 to 46% containing 44 to 47% crude protein were obtained. This compares favorably with Candida utilis, a yeast used commercially to produce single-cell protein. The chemical constituents and the essential amino acids of the fungal cells were similar to those of other fungi. The nucleic acid content was characteristic of microbes containing low levels of nucleic acid. The advantages of using S. acidophilum for single-cell protein production are discussed.
42 citations
TL;DR: There was significant interaction between the host plant and symbiont in determining nitrogenase activity and yield, and this screening method allows quantitative discrimination between effective and ineffective host-inoculum combinations.
Abstract: Five Rhizobium meliloti isolates known to have different capabilities for expression of nitrogenase activity under symbiotic conditions were used to inoculate four representative Medicago sativa cultivars under aseptic conditions. Nitrogenase activities and respiratory activity were measured for whole plants and excised nodules. Dry weights and nodule numbers were also recorded after 4 weeks of growth in plastic pouches on a nitrogen-free nutrient medium. Hydrogen evolution and acetylene reduction rates were used to calculate the fraction of reducing power allocated to dinitrogen reduction. Although the efficiency of the system defined in this way was poorly correlated with plant yield, a very high linear correlation was obtained between yield and the algebraic product of nitrogenase activity and efficiency. High correlation (r > 0.78) was obtained between respiration and nitrogenase activity for whole plants as well as for excised nodules. Nodular respiration accounted for between 10 and 20% of the total plant dark respiration. The four test cultivars exhibited significantly different symbiotic responses to the inocula, although trends in potential for expression of the nitrogenase system by the five R. meliloti strains were evident. There was significant interaction between the host plant and symbiont in determining nitrogenase activity and yield. This screening method allows quantitative discrimination between effective and ineffective host-inoculum combinations.
32 citations
30 citations
TL;DR: Observations on morphology and host associations of these larvae provide the basis for an original, though provisional, outline of phylogeny of Lebertioidea, and a review of the higher classification of the superfamily.
Abstract: Larvae of species representing 12 of the 13 genera of the superfamily Lebertioidea from North America are described, including members of the genera Bandakiopsis, Utaxatax, Estelloxus, and Testudacarus for the first time. Larvae of species of Sperchon, Sperchonopsis, Teutonia, Bandakia, Lebertia, Oxus, Frontipoda, and Torrenticola are also described to provide complete comparative data for the genera of the superfamily. A key to the families and genera of Lebertioidea, and preliminary diagnoses for the superfamily, families, and genera are provided based upon larval characters. Information on host associations is reviewed for each taxon. Observations on morphology and host associations of these larvae provide the basis for an original, though provisional, outline of phylogeny of Lebertioidea, and a review of the higher classification of the superfamily.
01 Jan 1982-Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes
TL;DR: The mobility of the compound in soil eluted with water was in the order, t.sulfone much greater than terbufos, in agreement with adsorption-desorption results, and rates in natural and sterilized water were similar indicating chemical degradation predominated.
Abstract: Terbufos, t. sulfoxide and t. sulfone (5 μg ml‐1) were incubated in natural, sterilized natural and distilled water, with initial pH values of 8.8, 8.8 and 6.0, respectively, at 20°C. First‐order disappearance was observed for the three compounds. Rates in natural and sterilized water were similar indicating chemical degradation predominated. Terbufos disappeared rapidly (t½>=3 days) in all systems. T. sulfoxide and t. sulfone were more persistent in the natural (t½>=18–40 days) and distilled water (t½>=280–350 days). Adsorption data for the three compounds in four soil‐water systems showed the decreasing order of adsorption to be terbufos>>t. sulfoxide=t. sulfone. Desorption from soils fortified at 5 μg g‐1 with water was examined for 4 successive 18‐hr cycles. T. sulfoxide and t. sulfone were totally desorbed; terbufos was too unstable to study. The mobility of the compound in soil eluted with water was in the order, t. sulfoxide=t. sulfone>> terbufos, in agreement with adsorption‐desorption re...
TL;DR: The systematics, phylogeny, and zoogeography of the genus and' species are discussed, and a checklist of Nearctic species is added.
Abstract: Twenty Nearctic species of Myllaena are recognized. All are redescribed or newly described and illustrated. A key for their identification, and maps of their distribution are provided. The species are arranged into four groups: the Cuneata , Insomnis , Potawatomi , and Seminole . Seven species are described as new: hopi (Arizona, Mexico), hopkinton (Massachusetts), kaskaskia (eastern U.S.A.), magnolia (Florida), potawatomi (transcontinental, also in Haiti and Jamaica), serrano (California, Baja California of Mexico), and seminole (southern U.S.A. and Illinois). Newly established synonymies are (the second name of each pair being valid): abdita Casey, 1911 = audax Casey, 1911; brevivestis Casey, 1911 = ludificans Casey, 1911; dissimulons Casey, 1911 = audax Casey, 1911; immunda Casey, 1911 = arcana Casey, 1911; molesta Casey, 1911 = audax Casey, 1911; obscurata Casey, 1911 = insipiens Casey, 1911; scobinella Casey, 1911 = decreta Casey, 1911; umbra Casey, 1911 = decreta Casey, 1911; and vegeta Casey, 1911 = audax Casey, 1911. Fourteen lectotypes are designated. A checklist of Nearctic species is added. The systematics, phylogeny, and zoogeography of the genus and' species are discussed.
TL;DR: The possible use of particle size separation of soils in water was tested for preparing fractions rich in unknown-N, which constitutes between 41 and 46% of the total N.
Abstract: The possible use of particle size separation of soils in water was tested for preparing fractions rich in ‘unknown’-N, which constitutes between 41 and 46% of the total N. Ten particle size fractions ranging from 1,000.0 μm were separated from the A horizon of the Bainsville soil, an Orthic Humic Gleysol, and from the Bh horizon of the Armadale soil, a poorly drained Podzol. The distribution of N (hydrolyzable-, amino acid-, protein-, amino sugar-, ammonia-, ‘unknown’-and unidentified-N) in the initial soils and in each size fraction was determined. While particle size separation did not yield fractions which contained essentially only ‘unknown’-N and few known N-components, it was possible to isolate fractions which were either rich in amino acid-or protein-N or in NH3-N. In general, the finer size fractions tended to be enriched in amino acid-N while NH3-N was more prominent in the coarser fractions. The amino sugar-N content of all size fractions was low.
TL;DR: The National Bureau of Standards as discussed by the authors found that residues contained element concentrations ranging from 0.05 to 88 times the respective concentrations in the samples, and contributed negligible (ca 0.1% for Mg and Ca), small (0.5% for Zn, Mn, K and 1% for Cu), and large (6% for Fe, 28% for Na) contributions depending on sample and analyte.
Abstract: Insoluble siliceous residues remaining after HNO3/HClO4 decomposition of the plant tissues National Bureau of Standards, standard reference materials spinach (Spinacea oleracea), orchard leaves and tomato leaves (Lycopersicon escuientum), contained varying quantities of the macro and micro elements Na, K, Mg, Ca, Mn, Fe, Cu and Zn. For the different samples with total element concentrations ranging from 11 μg/g (Cu in orchard leaves) to 45,000 μg/g (K in tomato leaves), residues contained element concentrations ranging from 0.05 to 88 times the respective concentrations in the samples. Contributions of residues to element concentrations in the plant tissues varied from 0.04 to 42% of the total concentrations. Overall, these constituted negligible (ca 0.1% for Mg and Ca), small (0.5% for Zn, Mn, K and 1% for Cu), and large (6% for Fe, 28% for Na) contributions depending on sample and analyte. Residue contributions to total element concentrations of plant tissues must be considered for reliable est...
TL;DR: The results indicate that the development of PPO activity is one of the earliest recognizable events in incompatible interactions and suggest that it is a consequence of cell damage that is induced by incompatible but not by compatible races.
Abstract: Etiolated 6-day-old soybean hypocotyls were inoculated with Phytophthora megasperma f. sp. glycinea by placing drops of zoospore suspensions onto the hypocotyl surface. Polyphenoloxidase (PPO) activity at the inoculated sites was determined after various periods of incubation by replacing the inoculum drops with l -β-3,4-dihydroxyphenylalanine ( l -Dopa) and measuring the formation of dopaquinone spectrophotometrically ( λ 480 n m ). Activity was detected at incompatibly-reacting sites within 2 to 3 h following inoculation. No activity was detected at compatibly-reacting sites, although these sites developed activity if subsequently re-inoculated with an incompatible race. Activity was also demonstrated in hypocotyl tissues injured by abrasion or localized freezing. The results indicate that the development of PPO activity is one of the earliest recognizable events in incompatible interactions and suggest that it is a consequence of cell damage that is induced by incompatible but not by compatible races.
TL;DR: Results suggest that at least one molecular mechanism of extracellular freezing injury involves the irreversible conversion of planar membrane bilayers to structures having less ordered packing and increased surface curvatures.
Abstract: Mesophyll cells isolated from cold-hardened and nonhardened winter rye ( Secale cereale L. cv. Puma) were spin-labeled with the fatty-acid spin probe N -oxyl-4,4-dimethyloxazolidine 5-ketostearic acid. The probe was intercalated within the cellular membranes and changes in probe motion were followed during extracellular freezing of the cells. A correlation was observed between the lethal freezing temperatures (LT 50 ) of the cells and the maximum hyperfine splitting value achieved by the incorporated probe. Rigid limit spectra indicated that a more ordered average packing was attained by membranes of hardened cells which survived freezing to lower temperatures. Nonhardened cells fixed with osmic acid at lethal freezing temperatures, in the frozen state, showed both conversion of normal bilayered cellular membrane ultrastructure to an amorphous state and condensation of cellular membranes to form densely packed multibilayered vesicles. Taken together with the spin-labeling data, these results suggest that at least one molecular mechanism of extracellular freezing injury involves the irreversible conversion of planar membrane bilayers to structures having less ordered packing and increased surface curvatures.
TL;DR: The following new species of Deinopsini are described and illustrated: Deinopsis apicicornis (southern USA), Adinopsis cuspidata (Florida, Maryland) and Adinopsis pubescens (Brazil, Colombia, Panama, Mexico).
Abstract: The following new species of Deinopsini are described and illustrated: Deinopsis apicicornis (southern USA), Adinopsis cuspidata (Florida, Maryland) and Adinopsis pubescens (Brazil, Colombia, Panama, Mexico). The previously unknown female of Gymnusa campbelli Klim., G. konopackii Klim., and Adinopsis braziliensis Klim., and the male of Metadeinopsis longicornis (Sharp), are described. New distribution and habitat date for some other species of the tribes are added.
TL;DR: The cessation of O2-uptake was shown to be due to the formation of excessive amounts of gaseous NH3, which not only inhibited microbial respiration by raising the pH to 8 and higher, but also by killing bacteria and actinomycetes.
Abstract: The biodegradability of nucleic acid bases (guanine, adenine, cytosine, thymine and uracil) adsorbed on montmorillonite, illite, kaolinite, soil, gibbsite, goethite and a fulvic acid (FA)-montmorillonite complex was investigated. Each material was mixed with sand, inoculated with a soil suspension and incubated in a Warburg vessel.
TL;DR: Results show that biochemical processes are of major importance in the transformation of phorate and its oxidation products in soil and the usefulness of appropriate partial rate constants in describing the processes involved is discussed.
Abstract: A sandy loam and a muck soil were sterilized by autoclaving, and samples were treated at 10 ppm with phorate, phorate sulfoxide, or phorate sulfone. These were incubated in the dark at 28°C, and samples were removed after 1, 2, 4, 8, 12, and 16 weeks and examined for microbial populations, pH, and insecticide concentrations. These variables also were determined in correspondingly treated natural soils. The three applied insecticides disappeared much more rapidly from the natural soils than from the sterilized soils. Phorate sulfoxide and phorate sulfone were observed as intermediate transformation products. In the sterile soils, phorate oxidation to phorate sulfoxide was the major process observed, and further oxidation of the sulfoxide did not occur. The expected increases in rates and changes in the products formed were observed as the sterile soils became nonsterile in time. Reduction of phorate sulfoxide to phorate was detected as a minor process in these contaminated soils. The results show that biochemical processes are of major importance in the transformation of phorate and its oxidation products in soil. The usefulness of appropriate partial rate constants in describing the processes involved is discussed.
01 Jan 1982
TL;DR: The method of analysis involved extraction, partitioning, multiple column chromatography with final quantitation being performed by gas chromatography/mass spectrometry using a packed column.
Abstract: Sixteen samples of 2,4-D ester and amine, both technical and formulated products, representing current Canadian supplies, were analysed for the presence of different chlorinated dibenzo-p-dioxins. The method of analysis involved extraction, partitioning, multiple column chromatography with final quantitation being performed by gas chromatography/mass spectrometry using a packed column. Isomer identification was achieved on a capillary column while dioxin identity was confirmed using high resolution mass spectrometry. The methodology provided for recoveries in excess of 85% with the limit of detection being 1 ppb. Eight out of nine esters and four our of seven amine samples were found to contain di-, tri- and tetra-chlorodibenzo-p-dioxins. Ester formulations showed significantly higher levels of contamination than the amine formulations. The tetra-chlorodioxin observed was the 1,3,6,8-isomer as verified by the synthesis of an authentic analytical standard. In addition ten 2,4-D technical acid samples from 4 different sources did not contain any mono-, di-, tri- or tetra-chlorodioxins above the 1 ppb detection limit, although low levels of polychlorinated biphenyl ethers were observed.
TL;DR: The significant finding was that all variables in fetal blood were stable during labour and, although mild hypercapnia was present during the last three hours, no significant changes in mean values were seen until those of samples taken within 15 minutes of birth.
TL;DR: It is inferred from observations that capability for resistance was transferred with grafts of resistant skin to the nude recipients from which no contribution was necessary for the development of resistance, and that an intact T-cell contribution is necessary forDevelopment of resistance in normal skin.
Abstract: Further evidence is presented that acquired resistance of mice to lice is locally mediated. Normal, previously unexposed skin transplanted to athymic nude mice was readily colonized by lice and did not acquire resistance, but louse-resistant skin similarly grafted remained resistant for at least 12 weeks. It is inferred from these observations that capability for resistance was transferred with grafts of resistant skin to the nude recipients from which no contribution was necessary for the development of resistance, and that an intact T-cell contribution is necessary for development of resistance in normal skin. Such adequate contribution is not imparted to the nude host by grafts from normal donor hosts nor is such capability transferred to normal grafts from resistant skin grafted on the same animals.
TL;DR: Efficiency of food conversion was constant, but efficiency of protein conversion was influenced by dietary protein and dietary mycotoxin concentration, and a new technique for determining food utilization by insect larvae is described.
TL;DR: Results show that biochemical processes are of major importance in the transformation of terbufos and its oxidation products in soil and that the greater persistence of the “total residue” from terbufo treatment in the organic soil was due to more rapid conversion of the ter bufos to terbufOS sulfoxide combined with a slower rate of degradation of Terbufos sulfoxide and terbufus sulfone.
Abstract: A sandy loam and a muck soil were sterilized by autoclaving, and samples were treated at 10 ppm with terbufos, terbufos sulfoxide, or terbufos sulfone. These were incubated in the dark at 28°C; samples were removed after 1, 2, 4, 8, 12, 16, and 20 weeks and were examined for microbial populations, pH, and insecticide concentrations. These variables were determined also in correspondingly treated natural soils. Residual insecticide determinations were simplified by acid treatment of the solid support used to prepare gas-liquid chromatography (GLC) columns, which permitted direct analysis of at least 0.05 ng of terbufos sulfoxide and separation from 100-fold greater quantities of terbufos sulfone by GLC. In the natural soils, all three applied insecticides disappeared much more rapidly than from the sterilized soils, and terbufos sulfoxide and terbufos sulfone were observed as intermediate transformation products. In the sterilized soils, terbufos oxidation to terbufos sulfoxide was the major observable process, but the rate of oxidation was slower than in the natural soils and further oxidation to the sulfone was not observed. Terbufos sulfone also was stable in the sterilized soils. These results show that biochemical processes are of major importance in the transformation of terbufos and its oxidation products in soil. Partial-rate constants for the processes described showed that the greater persistence of the “total residue” from terbufos treatment in the organic soil was due to more rapid conversion of the terbufos to terbufos sulfoxide combined with a slower rate of degradation of terbufos sulfoxide and terbufos sulfone.
TL;DR: It is concluded that phylogenetic reconstruction must not only reflect the branching patterns suggested by cladistic analysis but also take account of the tionary history that is reflected in an optimal phenogram.