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341.
Zaugg J Potterat O Plescher A Honermeier B Hamburger M 《Journal of agricultural and food chemistry》2006,54(18):6623-6628
Lipophilic triterpenoidal esters with radical scavenging and cyclooxygenase inhibitory properties were recently found in cold-pressed, nonraffinated evening primrose oil (EPO). A quantitative assay for the analysis of 3-O-trans-caffeoyl derivatives of betulinic, morolic, and oleanolic acid in evening primrose seeds was developed and validated. Extraction efficiency >99% was achieved by means of pressurized liquid extraction with two extraction cycles and 80% (v/v) ethanol at 120 degrees C. Analysis of esters was by normal-phase high-performance liquid chromatography on a Diol column and hexane/ethyl acetate (containing 0.1% formic acid) (65:35) as the eluent. The analytes were determined without further prepurification. Seeds from defined cultures of Oenothera biennis, Oenothera lamarckiana, and Oenothera ammophila, grown under identical conditions, were analyzed. The cultures originated from seeds from eight collections in the wild and from selections from five cultivars. The content of total triterpenoidal esters in seeds varied between 1.34 and 2.78 mg/g. Three types of qualitative patterns were observed for the triterpenoidal esters. The influence of different harvest times and plant treatments was studied with the cultivar Anothera. Variations between 1.5 and 2.3 mg/g were found. 相似文献
342.
Manning SW Ramsey CB Kutschera W Higham T Kromer B Steier P Wild EM 《Science (New York, N.Y.)》2006,312(5773):565-569
Radiocarbon (carbon-14) data from the Aegean Bronze Age 1700-1400 B.C. show that the Santorini (Thera) eruption must have occurred in the late 17th century B.C. By using carbon-14 dates from the surrounding region, cultural phases, and Bayesian statistical analysis, we established a chronology for the initial Aegean Late Bronze Age cultural phases (Late Minoan IA, IB, and II). This chronology contrasts with conventional archaeological dates and cultural synthesis: stretching out the Late Minoan IA, IB, and II phases by approximately 100 years and requiring reassessment of standard interpretations of associations between the Egyptian and Near Eastern historical dates and phases and those in the Aegean and Cyprus in the mid-second millennium B.C. 相似文献
343.
Reinhold Siede Lena Faust Marina D Meixner Christian Maus Bernd Grünewald Ralph Büchler 《Pest management science》2017,73(7):i-i
The cover image, by Reinhold Siede et al., is based on the Research Article Performance of honey bee colonies under a long‐lasting dietary exposure to sublethal concentrations of the neonicotinoid insecticide thiacloprid ?, DOI: 10.1002/ps.4547 .
344.
Spontaneous outcrossing in tomato depends on cultivar and environment and varies between individual flowers 下载免费PDF全文
Knowledge about the degree of spontaneous outcrossing of diverse genotypes is essential for breeding programmes, maintenance breeding, and seed production. For tomato (Lycopersicon esculentum Mill.), very limited scientific evidence for genotypic differences is available and evidence from Europe is scarce. To close this knowledge gap, six cultivars were investigated in three Central European locations as part of the Organic Outdoor Tomato Project. To determine outcrossing rates, the monogenetic “cut‐leaf” trait, which is dominant over the “potato‐leaf” trait, was used as morphological marker. The observed range of outcrossing was 0.0%–5.2%. Outcrossing was significantly influenced by cultivar and environment. The outcrossing rate of individual flowers varied within cultivars ranging from 0% to 37%. The potential of newly opened flowers to accept foreign pollen varied largely with the cultivar. Genotypic differences could partly be linked to flower morphology traits. The potential for recombination between tomato genotypes is generally very low but can be a source for new variation in on‐farm management. 相似文献
345.
The objective of this study was to determine how to establish high and stable yields of winter rye under the impact of highly varying seeding densities and delayed sowing date. A field trial with three winter rye cultivars (two population cultivars and one F1 hybrid) was conducted on a sandy site over a period of three years. The results showed that seeding density, cultivar choice, and annual weather conditions are important factors impacting the yield variability of winter rye. Higher seeding densities led to higher and slightly more stable yields of winter rye. Moreover, a cultivar-adapted seeding date seemed to exploit yield potential advantageously. Interestingly, all three cultivars showed better yield stability with a two-week delay in seeding date. This study suggests that cultivar choice and management practices such as modulation of seeding date and seeding density play an important role in improving the grain yield and yield stability of winter rye. 相似文献
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