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991.
The aim of our studies was to determine the relation between temperature and the respiration rate of the forest soil organic
layer along an altitudinal gradient while controlling the effects of the soil characteristics. The respiration rate was measured
in laboratory conditions at different temperatures, 0, 10, 20, and 30°C, in samples collected in the Polish part of the Western
Carpathians at 600, 800, 1,000, and 1,200 m above sea level from four different mountains, which were later treated as replicates.
The increase in the average respiration rate between two consecutive temperatures was expressed as Q
10 coefficients. Among the nutrients measured in the soil organic layer, only the total organic N concentration significantly
increased with elevation. The temperature effect was significant for both the respiration rate and the Q
10 values. The calculated Q
10 values were highest for the temperature range between 10 and 20°C, and the lowest values were obtained from the highest temperature
range (20–30°C). The altitude effect was significant for the respiration rate but not for the Q
10 values, indicating that the temperature sensitivity of the soil respiration did not change much along the studied altitudinal
gradient. 相似文献
992.
Summary Our studies have revealed that streptomycetes inhabiting root-free soil and the root zone of pine trees differ in their capacity to produce cellulolytic and pectolytic enzymes. Most of the root-zone organisms but only a few of the root-free soil isolates exhibited cellulolytic activity. A few of the root-zone organisms but no soil isolate showed pectolytic activity. In general the cellulolytic activity was higher in cellulase producers from the root zone than in those derived from the root-free soil. The streptomycetes studied produced only endopolymethylgalacturonase. The mean total activity of this enzyme was higher in the rhizosphere isolates but the mean specific activity was higher in the mycorrhizosphere organisms. 相似文献
993.
Block E Glass RS Jacobsen NE Johnson S Kahakachchi C Kamiński R Skowrońska A Boakye HT Tyson JF Uden PC 《Journal of agricultural and food chemistry》2004,52(12):3761-3771
After proteolytic digestion, aqueous extraction, and derivatization with diethyl pyrocarbonate or ethyl chloroformate, HPLC-inductively coupled plasma (ICP)-MS, GC-atomic emission detection (AED), and GC-MS analysis of high-selenium yeast stored at room temperature for more than 10 years showed selenomethionine as the major Se product along with substantial amounts of selenomethionine selenoxide hydrate and the previously unreported selenoamino acid having a Se-S bond, S-(methylseleno)cysteine. The identity of the latter compound was confirmed by synthesis. The natural product was shown to be different from a synthetic sample of the isomeric compound Se-(methylthio)selenocysteine. Selenium-specific NMR spectroscopic methods were developed to directly analyze the aqueous extracts of the hydrolyzed selenized yeast without derivatization or separation. Selenomethionine and S-(methylseleno)cysteine were identified by 77Se-1H HMQC-TOCSY experiments. 相似文献
994.
Szafranek B Chrapkowska K Pawińska M Szafranek J 《Journal of agricultural and food chemistry》2005,53(8):2817-2822
A comparative study of potato leaf sesquiterpenes was carried out. GC, GC-MS, and NMR analyses were used to identify and quantify the sesquiterpenes in the leaf surfaces of 10 potato (Solanum tuberosum) varieties. Two sesquiterpene alcohols and 17 sesquiterpene hydrocarbons were identified and quantitatively determined. The distribution of the sesquiterpenes was found to be variety-specific. The sesquiterpene contents of the different potato varieties were subjected to cluster and principal component analyses. The eight potato varieties of the main chemotype cluster were dominated by beta-caryophyllene (9-148 ng/cm2), germacrene D (2-46 ng/cm2), germacrene D-4-ol (0.4-31 ng/cm2), beta-sesquiphellandrene (1-34 ng/cm2), and an unknown sesquiterpene alcohol III (0.2-37 ng/cm2). Chemometric classification distinguished two varieties, Mila and Vistula, from a major cluster. The Vistula variety was distinguished from the others by its high contents of beta-caryophyllene, alpha-humulene, germacrene D, and germacrene D-4-ol and the Mila variety by beta-elemene, trans-alpha-bergamotene, (Z)-beta-farnesene, (E)-beta-farnesene, trans-beta-bergamotene, beta-sesquiphellandrene, and unknown sesquiterpene alcohols I, II, III. 相似文献
995.
Bioindication of air pollution effects has received considerable attention in recent years. It has been almost entirely focused on individual species and relatively little notice has been given to ecosystem level process and function monitors. Longterm research projects in the Niepolomice Forest in southern Poland and the Colstrip area in southeast Montana, U.S.A., were analyzed for both organismic and system level indicators and monitors for SO, trace elements, and fluoride pollution originating in nearby coal-fired industrial processes. Species of lichens exhibited changes in morphology and survival and pine species exhibited pollutant accumulation in needles at both sites. Declines in Scotch pine growth in Poland of up to 20% were compared with declines in western wheatgrass rhizone biomass in Montana to illustrate system wide effects on primary productivity. Directly observable declines in decomposition rate were noted for both sites at higher pollution levels and tied to system wide occurrences of nutrient deficiency and toxicant buildup in soil pools. Pollutant increases in deer antler composition, changes in grasshopper dietary patterns, and lichen density and health were postulated to have system level implications as well. 相似文献
996.
Skwarzec Bogdan Boryło Alicja Strumińska Dagmara I. 《Water, air, and soil pollution》2004,159(1):165-173
The aim of the work was to determine the concentration of 234U and 238U and calculate the values of the 234U/238U activity ratio in samples of living organisms, bottom water, surface and interstitial water and also sediments from the various regions of southern Baltic Sea. The knowledge of 234U/238U activity ratio in ecosystem allows getting know about the mechanisms and processes of uranium transport and origin.The activities of the analyzed uranium radionuclides in samples were measured using alpha spectrometry. The results of researches revealed diversified concentrations of uranium in the sediments of the southern Baltic Sea (sea and coastal waters) and increase of uranium with sediment depth, suggesting the diffusion of uranium from sediments to water through interstitial water and diagenesis processes in sediment material. The nuclides of uranium 234U and 238U were radioactive state equilibrium in most of the sediments. The values of the 234U/238U activity ratio oscillate around one. In bottom, surface, interstitial water and living organisms mean values of the 234U/238U activity ratio are between 1.12 and 1.15. Higher uranium concentration was observed in samples of sediments and seawater after flood in 1997 and torrential rainfalls in 2000–2001. River waters are characterized by higher 234U/238U activity ratio. The values of the 234U/238U activity ratio equal 1.27 in sediments and 1.34–1.38 in seawater indicate the influence of fresh waters. 相似文献
997.
Summary The diploid clone DW.84-1457 which has outstanding resistance to potato leafroll virus (PLRV), has been selected at the Mlochów
Centre of the Institute for Potato Research. It has in its pedigree PLRV-resistant clones from the Max Planck Institute nos.
MPI 44.1016/10, MPI 44.335/130 and MPI 49.540/2. Its behaviour in the field and response to aphid inoculation indicate high
resistance to infection, and the low concentration of the virus in graft-inoculated plants indicates high resistance to multiplication.
This combination within one genotype of two aspects of resistance is not connected with hypersensitivity, and is heritable.
Clone DW.84-1457 has other desirable characters such as extreme resistance to potato virus X (PVX), high resistance to potato
virus M (PVM) and good table and processing quality. It is being utilized in the development of parental lines, both at the
diploid and tetraploid level. 相似文献
998.
Mildner-Szkudlarz Sylwia Siger Aleksander Przygoński Krzysztof Radziejewska-Kubzdela Elżbieta Zawirska-Wojtasiak Renata 《Plant foods for human nutrition (Dordrecht, Netherlands)》2022,77(2):190-197
Plant Foods for Human Nutrition - We investigated the changes in N?-(carboxymethyl)lysine (CML) and available lysine content, antioxidant properties, volatiles, and oxidation products of... 相似文献
999.
Summary Diploid parents with some resistance to PLRV, were intercrossed to give 3 families with 191 clones which were evaluated for
reaction to PLRV and yielding ability. After inoculation with PLRV the clones could be separated into those: 1) resistant,
2) susceptible, 3) intolerant, reacting with low virus concentration, 4) tolerant and 5) intermediate in reaction. Both the
ELISA test and the evaluation of external disease symptoms were necessary to separate the clones. No correlation was found
between resistance to PLRV and tuber yielding ability. 相似文献
1000.