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1.
J. W. Hanna N. B. Klopfenstein M.‐S. Kim G. I. McDonald J. A. Moore 《Forest Pathology》2007,37(3):192-216
Nuclear ribosomal DNA regions (i.e. large subunit, internal transcribed spacer, 5.8S and intergenic spacer) were sequenced using a direct‐polymerase chain reaction method from Armillaria ostoyae genets collected from the western USA. Many of the A. ostoyae genets contained heterogeneity among rDNA repeats, indicating intragenomic variation and likely intraspecific hybridization. Intragenomic variation was verified by visually editing base‐sequence offsets in regions with insertions/deletions, and using sequence‐specific internal primers to resequence heterogeneous regions. Phylogenetic analyses with Bayesian Inference methods were used to define groups within A. ostoyae. Analysis of A. ostoyae from outside the western USA indicated the presence of a Circumboreal group of A. ostoyae that also occurs in Utah; two other phylogeographic groups were associated with the Rocky Mountain and Pacific Northwest regions of the USA. Mixed sequence types, an indication of intraspecific hybrids, were common in some geographic regions. Hybridization events may have influenced species evolution, contributing to variation in pathogenicity and virulence. The occurrence of these groups and intraspecific hybrids also indicates that paleogeography and paleoclimate may have influenced the phylogeography of A. ostoyae. In addition, other Armillaria species were examined for evolutionary relationships with the groups of A. ostoyae. These findings will provide a basis for future research relating ecological function to genetic diversity within A. ostoyae. 相似文献
2.
Oscar Nordahl Per Koch‐Schmidt Johanna Sunde Yeerin Yldrm Petter Tibblin Anders Forsman Per Larsson 《水产资源保护:海洋与淡水生态系统》2019,29(11):1923-1935
- Aquatic systems often lack physical boundaries for gene flow, but ecological and behavioural barriers can form surprisingly fine spatial scale genetic patterns that challenge traditional, large scale management. To detect fine spatial scale structures, understand sources of intraspecific diversity, and design appropriate management plans requires identification of reproductively isolated units.
- This study reports on genetic differentiation in pike (Esox lucius) within a coastal area stretching 55 km from south to north in the central Baltic Sea. Pike is here an economically and ecologically important top predator that has declined in abundance. However, population structures have mostly been studied on large spatial scales, and without considering the potential for genetic divergence between the sympatric anadromous fresh water and the resident brackish water spawning ecotypes.
- To this end, 487 individuals from the east coast of Sweden and the island of Öland, representing sympatric anadromous and resident spawning individuals, categorized to ecotype based on spawning location or otolith microchemistry, were genotyped for 10 microsatellites and used to test for divergence between ecotypes. Furthermore, divergence between regions (island/mainland), neighbouring spawning locations (n = 13) and isolation by distance within and between regions were evaluated for the anadromous ecotype.
- The results revealed strong genetic differences between regions, between spawning locations separated by as little as 5 km and the first evidence of genetic differentiation between resident and anadromous ecotypes; despite a high dispersal capacity of pike and a high connectivity within the study area. The signatures of isolation by distance indicated that connectivity among populations differed between regions, probably reflecting availability of spawning habitats.
- To safeguard against the challenges and uncertainties associated with environmental change, adaptive conservation management should aim to promote high intra‐population functional genetic diversity without compromising the continued integrity and coexistence of the different ecotypes and of locally adapted sub‐populations.
3.
Boy J.H.M. Possen Elina OksanenMatti Rousi Hanna RuhanenViivi Ahonen Arja TervahautaJaakko Heinonen Juha HeiskanenSirpa Kärenlampi Elina Vapaavuori 《Forest Ecology and Management》2011,262(8):1387-1399
For northern Europe’s climate, models predict an increase in periods of drought and waterlogging. Knowledge of variation between genotypes of Betula pendula (birch) and Populus tremula (aspen) to drought and excess soil moisture are unavailable but relevant for future development of forest ecosystems. We studied variation between genotypes to soil moisture in birch and aspen with plant material representing naturally regenerated populations and showed differences in acclimation to soil moisture conditions. Genotypes showing most growth and biomass accumulation across treatments maintained most leaf area, high gas exchange and water-use efficiency and grew most root mass but had the lowest root length per unit root dry mass compared to other genotypes. This indicates that these genotypes are more efficient in harvesting water from the soil under adverse conditions. We also showed that birch and aspen employ different strategies to cope with soil moisture conditions, with aspen investing more in perennial parts, while birch efficiently maintains foliar processes. When the expression of some known drought responsive genes was measured, only ACC oxidase was induced by the drought treatment at the beginning of the experiment, while surprisingly LEA5, RD22 and ADH1 did not respond to drought, but were up-regulated in prolonged wet conditions indicating oxidative stress and hypoxia and that these genes are responding to multiple stress factors. We conclude that in plants micro-propagated from naturally regenerated birch and aspen populations, there is variation between genotypes in acclimation efficiency to soil moisture conditions. 相似文献
4.
B K Larsson 《Journal of the Association of Official Analytical Chemists》1983,66(3):775-780
A gas-liquid chromatographic method for the simultaneous determination of benzoic acid and sorbic acid in foods was collaboratively studied by 8 laboratories. Benzoic and sorbic acids are isolated from food by successive extractions with ether, sodium hydroxide, and methylene chloride, converted to trimethylsilyl (TMS) esters, and determined by gas-liquid chromatography. Phenylacetic acid and caproic acid are used as internal standards for benzoic acid and sorbic acid, respectively. Seven samples were collaboratively studied: almond paste, fish homogenate, and apple juice with benzoic and sorbic acid levels from 0.04 to 2 g/kg. Average recoveries (%) for benzoic and sorbic acids were as follows: almond paste, 99.6 and 101.2; fish homogenate, 99.2 and 97.4; and apple juice 98.2 and 106.6. The reproducibility coefficients of variation (%) for benzoic and sorbic acids at 0.5-2 g/kg levels were 3.5-6.1 and 5.2-9.0; and at the 0.04 g/kg level, 14.7 and 23.3, respectively. The method has been adopted official first action at 0.5-2 g/kg levels. 相似文献
5.
Haruenkit R Poovarodom S Leontowicz H Leontowicz M Sajewicz M Kowalska T Delgado-Licon E Rocha-Guzmán NE Gallegos-Infante JA Trakhtenberg S Gorinstein S 《Journal of agricultural and food chemistry》2007,55(14):5842-5849
In vitro and in vivo studies of the health and nutritional properties of durian (Durio zibethinus Murr.) were compared with snake fruit (Salacca edulis Reinw.) and mangosteen (Garcinia mangostana). Dietary fibers, minerals, and trace metals were comparable. Total polyphenols (mg of GAE/100 g of FW) and flavonoids (85.1+/-6.1) were significantly higher (p<0.05) than in snake fruit (217.1+/-13.2 (mg of CE/100 g of FW)), durian (309.7+/-19.3 and 61.2+/-4.9), and mangosteen (190.3+/-12.1 and 54.1+/-3.8). Antioxidant activity (microM TE/100 g of FW) of durian measured by DPPH and ABTS assays (228.2+/-13.4 and 2016.3+/-81.1) was significantly higher (p<0.05) than in snake fruit (110.4+/-7.9 and 1507.5+/-70.1) and mangosteen (79.1+/-5.9 and 1268.6+/-62.3). HPLC/DAD analysis of durian (microg/100 g of FW) showed that quercetin (1214.23+/-116.7) was present at levels three times that of caffeic acid, and twice as high as p-coumaric and cinnamic acids. The correlation coefficients between the bioactive compounds of fruits and their antioxidant activities were high (R2=0.99). Male Wistar rats (25) were divided into five dietary groups: the control group was fed the basal diet (BD); in addition to BD, the cholesterol (Chol) group was supplemented with 1% of Chol; the diets of the Chol/Durian, Chol/Snake, and Chol/Mangosteen groups were supplemanted with 5% of these fruits, respectively. It was found that diets supplemented with durian, and to a lesser degree with snake fruit and mangosteen, significantly hindered the rise in plasma lipids and the decrease in antioxidant activity. The nutritional values were comparably high. In conclusion, it could be suggested that inclusion of studied tropical fruits, especially durian, in known disease-preventing diets could be beneficial. 相似文献
6.
Leontowicz M Gorinstein S Leontowicz H Krzeminski R Lojek A Katrich E Cíz M Martin-Belloso O Soliva-Fortuny R Haruenkit R Trakhtenberg S 《Journal of agricultural and food chemistry》2003,51(19):5780-5785
The aim of this study was to assess the bioactive compounds of apple and pear peel and pulp in vitro and their influence on plasma lipids and antioxidant potentials in vivo. The antioxidant potentials measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH), beta-carotene bleaching (beta-carotene), and nitric oxide inhibition radical scavenging (NO) tests in apple peel and pulp were significantly higher than in pear peel and pulp, respectively. The ethanol extract of apple peels showed the strongest inhibition of lipid peroxidation as a function of its concentration and was comparable to the antioxidant activity of butylated hydroxyanisole. The pear pulp extract had the weakest antioxidant ability, whereas other extracts such as apple pulp and pear peel were nearly equal. The antioxidant activities comprised contributions from polyphenols, phenolic acids, and flavonoids and correlated well with polyphenols and flavonoids. The correlation coefficients between polyphenols and antioxidant activities by DPPH, beta-carotene, and NO were as follows: 0.9207, 0.9350, and 0.9453. Contrarily, the correlation coefficient between the content of dietary fiber and the antioxidant activities test was low. The content of all studied indices in apple and pear peel was significantly higher than in peeled fruits (p < 0.05). Diets supplemented with fruit peels exercised a significantly higher positive influence on plasma lipid levels and on plasma antioxidant capacity of rats than diets with fruit pulps. 相似文献
7.
Balakshin MY Capanema EA Chen CL Gracz HS 《Journal of agricultural and food chemistry》2003,51(21):6116-6127
Comparative studies on the structures of residual and dissolved lignins isolated from pine kraft pulp and pulping liquor have been undertaken using the (1)H-(13)C HMQC NMR technique, GPC, and sugar analysis to elucidate the reaction mechanisms in kraft pulping and the lignin reactivity. A modified procedure for the isolation of enzymatic residual lignins has resulted in an appreciable decrease in protein contaminants in the residual lignin preparations (N content < 0.2%). The very high dispersion of HMQC spectra allows identification of different lignin moieties, which signals appear overlapped in 1D (13)C NMR spectra. Elucidation of the role of condensation reactions indicates that an increase in the degree of lignin condensation during pulping results from accumulation of original condensed lignin moieties rather than from the formation of new alkyl-aryl structures. Among aryl-vinyl type moieties, only stilbene structures are accumulated in lignin in appreciable amounts. Benzyl ether lignin-carbohydrate bonds involving primary hydroxyl groups of carbohydrates have been detected in residual and dissolved lignin preparations. Structures of the alpha-hydroxyacid type have been postulated to be among the important lignin degradation products in kraft pulping. The effect of the isolation method on the lignin structure and differences between the residual and dissolved lignins are discussed. 相似文献
8.
G M Hanna C A Lau-Cam 《Journal of the Association of Official Analytical Chemists》1989,72(4):556-558
Use of proton nuclear magnetic resonance spectroscopy and the lanthanide shift reagent, Eu(hfc)3, resulted in a simple and reliable method for determination of the diastereomeric purity of trans-2-phenylcyclopropylamine sulfate (tranylcypromine sulfate). Eu(hfc)3 effectively simplified the complex overlapping pattern of the 5 non-equivalent phenyl protons to a virtually first order pattern. At a shift reagent to substrate molar ratio of 0.75, and a substrate concentration of 0.25M (as the free base) in CDCl3, the resonances for the cis- and trans-ortho-phenyl protons at 11.39 and 9.99 ppm, respectively, were sufficiently resolved to be of use in quantitative work. Analysis of synthetic diastereomeric mixtures of 2-phenylcyclopropylamine sulfate by the proposed method yielded results that were in close agreement with the expected values. The mean recovery (SD) of trans-diastereomer was 100.51% (0.40) (n = 6). Levels of less than 2% of cis-diastereomer were measurable in cis-trans mixtures. 相似文献
9.
Zykwinska A Boiffard MH Kontkanen H Buchert J Thibault JF Bonnin E 《Journal of agricultural and food chemistry》2008,56(19):8926-8935
Green labeled pectins were extracted by an environmentally friendly way using proteases and cellulases being able to act on proteins and cellulose present in cell walls. Pectins were isolated from different plant byproducts, i.e., chicory roots, citrus peel, cauliflower florets and leaves, endive, and sugar beet pulps. Enzymatic extraction was performed at 50 degrees C for 4 h, in order to fulfill the conditions required for microbiological safety of extracted products. High methoxy (HM) pectins of high molar mass were extracted with three different enzyme mixtures. These pectins were subsequently demethylated with two pectin methyl esterases (PMEs), either the fungal PME from Aspergillus aculeatus or the orange PME. It was further demonstrated that high molar mass low methoxy (LM) pectins could also be extracted directly from cell walls by adding the fungal PME to the mixture of protease and cellulase. Moreover, health benefit pectic oligosaccharides, the so-called modified hairy regions, were obtained after enzymatic treatment of the residue recovered after pectin extraction. The enzymatic method demonstrates that it is possible to convert vegetable byproducts into high-added value compounds, such as pectins and pectic oligosaccharides, and thus considerably reduce the amount of these residues generated by food industries. 相似文献
10.
D A Kline G R Hanna C B Honaker G O Kuhn C W Jameson 《Journal of the Association of Official Analytical Chemists》1986,69(4):660-663
Studies at Midwest Research Institute for the National Toxicology Program show that rotenone/animal feed mixtures prepared by dry-mixing are more stable than mixtures produced by dosing the feed with alcoholic solutions of rotenone and then stripping the solvent. Also, recoveries of rotenone from the dry mix feeds are higher than those from feeds dosed by the solution method. A simplified analytical method from one previously reported for rotenone in feed is described. 相似文献