Variation in the flavonol glycoside composition of almond seedcoats as determined by maldi-tof mass spectrometry     

Frison S  Sporns P 《Journal of agricultural and food chemistry》2002,50(23):6818-6822

Seedcoats of 16 almond varieties were screened for flavonol glycosides by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Flavonol glycosides were extracted by a simple methanolic extraction followed by a quick cleanup procedure with a Sep-Pak C(18) cartridge. Each of the 16 seedcoat samples exhibited a unique composition. Four flavonol glycosides, isorhamnetin rutinoside, isorhamnetin glucoside, kaempferol rutinoside, and kaempferol glucoside, were detected and quantified with use of rutin as an internal standard. Individual peak ratios were very consistent across triplicate analyses of all samples; the average standard deviation was 9%. In all almond varieties, isorhamnetin rutinoside was the most abundant flavonol glycoside, and the total content ranged from 75 to 250 microg/g.  相似文献   

Mobility decisions and the predation risks of reintroduction     

Peter B Banks  Kai NorrdahlErkki Korpimäki 《Biological conservation》2002,103(2):133-138

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Variation in primitive landraces of common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) from Argentina     

Antonio M. De Ron  María C. Menéndez-Sevillano  Marta Santalla 《Genetic Resources and Crop Evolution》2005,51(8):883-894

The phenotypic variation found in four common bean (Phaseolus vulgaris L.) complex primitive landraces, among a group of accessions collected in Northwestern Argentina in several missions is described, with particular attention to the wide diversity found in some small areas. It is presented a hypothesis about the maintenance of such diversity in bean mixtures or complex primitive landraces that grow close to their wild relative. Wide diversity regarding to seed type and plant characteristics was displayed by the landraces MCM-SV (composed of 11 lines), MCM-292 (14 lines), MCM-298 (5 lines) and VAV-3716 (14 lines). Food uses of dry seed and fresh pod seemed to be more relevant than the aesthetic use although all of them were presumably considered by humans for centuries resulting in the current phenotypes of these complex primitive landraces. Additionally, some weedy types (intermediate between wild and domesticated types) were detected in the landracesMCM-292 and MCM-298. The four complex landraces described consisted of highly diverse mixtures and they could play a role in breeding to enlarge the genetic basis of domesticated bean varieties belonging to the Andean gene pool.  相似文献   

Comparison of accelerator mass spectrometry with gas chromatography for the determination of pesticide residues in individual items in the diets of wild birds and mammals     

Brown P  Garner C  Glass R  Ridgway C  Hart A 《Journal of agricultural and food chemistry》2004,52(12):3693-3701

Methods to refine the assessment of exposure of wild birds and mammals to pesticides required measurement of pesticide residues in very small samples of their diets. Sample sizes were in the 1-100 mg range, and the target residue for measurement was 0.01 mg/kg. Gas chromatography-mass spectrometry (GC-MS) with large volume injection was compared with the use of an accelerator mass spectrometer (AMS) to measure residues of pesticide labeled at near-background levels with carbon-14. The GC-MS method was able to detect residues down to 0.1 ng per item of diet, and the AMS detected the radiolabel down to 1 mBq (0.06 disintegration per minute, 1 ng of pesticide at the specific activity used) per sample. The target residue level was achieved by the GC-MS method for samples down to 10 mg. The GC method appeared to be best suited to monitoring residues in field studies, and the AMS shows great potential for use in laboratory experiments concerning pesticide degradation.  相似文献   

Effects of carbon source amendment on the anaerobic degradation of 1,1,1-trichloroethane (TCA) in a contaminated aquifer     

R. Lookman  B. Borremans  T. De Ceuster  J. Gemoets  L. Diels 《Water, air, and soil pollution》2005,166(1-4):197-216

We conducted a 10-month anaerobic microcosm test and a 15-month field test to investigate the effects of carbon source addition on the in-situ 1,1,1-trichloroethane (TCA) degradation in a polluted aquifer at an industrial site near Antwerp, Belgium. In the microcosms TCA decreased from 15000 μ g/L to 1500 μ g/L. 1,1-Dichloroethane (DCA) end-concentrations were about the same as the concentrations at the start of the tests (1500 μ g/L). 1,1-Dichloroethene (DCE) decreased from 1200 μ g/L to 800 μ g/L. Carbon source unamended and amended microcosms showed equal concentration trends. Neither chloroethane (CA) nor vinyl chloride (VC) were produced in the microcosms. In the field test TCA dropped from 15000 μ g/L to below 2000 μ g/L. Upstream, TCA levels remained elevated proving that the C-source injection had stimulated degradation. Sulphate reducing bacteria were stimulated; FeS was produced in the microcosms and aquifer. Dehalococcoides species were stimulated in some microcosms and in the HRC-amended aquifer. Neither sulphate reducers nor Dehalococcoidesspecies are however believed to be responsible for the observed TCA degradation. The carbon source injection however did yield environmental conditions that increased TCA degradation.  相似文献   

Soil science simplified: M.I. Harpstead and F.D. Hole,illustrated by M. Bratz. Iowa University Press,Ames, Iowa, 1980, 122 pp. US$7.75     

H. De Bakker 《Geoderma》1982,28(1):64

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Conservation of freshwater fishes of Sri Lanka     

F. Ranil Senanayake  Peter B. Moyle 《Biological conservation》1982,22(3):181-195

Sri Lanka supports a diverse fauna of freshwater fishes, 24% of which are endemic. A survey of the island's streams indicated that a number of the endemic fishes are threatened with extinction and others are depleted due to the interaction of deforestation, urbanization, gem mining, pesticides, exploitation, water diversions, and introductions of exotic species. It is clear that these declines should be halted for ethical, economic, and ecological reasons. Methods proposed to reverse the declines include captive breeding, better watershed management, translocation, and regulation of fisheries, especially that for aquarium fishes. The depauperate Second Peneplain is proposed as a site for translocation of endangered species.  相似文献   

Aluminium and uptake of base cations by tree roots: A critique of the model proposed by Sverdrup et al.     

Peter Högberg  Paul Jensén 《Water, air, and soil pollution》1994,75(1-2):121-125

Sverdrupet al. (1992) proposed a model intended to evaluate effects of soil solution (Ca²⁺+Mg²⁺/Al³⁺ ratios on the uptake of Ca²⁺ and Mg²⁺ (here called base cations=BC) by tree roots. They considered the adsorption of BC on exchange sites on root surfaces to be a major step, and the competition between Al³⁺ and BC for exchange sites on roots to be crucial. Although this may certainly affect the rates of uptake, it will not exclude base cations from entering the root cells through ion channels or by carriers. Above all, the model overlooks important gradients in the rhizosphere, e.g. pH-gradients and root exudates, which have profound influences on the speciation of Al. One should instead consider modifying existing models accounting for processes in a buffered soil medium and handling gradients in the rhizosphere (e.g. Nye and Tinker, 1977). This would also require considerations on mycorrhizas and possible changes in the capacity for uptake of certain ions, which could be induced by deficiencies.  相似文献   

Relative importance of natural and anthropogenic proton sources in soils in The Netherlands   总被引：1，自引：0，他引：1  

W. De Vries  A. Breeuwsma 《Water, air, and soil pollution》1986,28(1-2):173-184

Dissociation of weak acids is shown to be the main cause of natural proton (acid) production. We have quantified this proton source for calcareous and non-calcareous sandy soils in The Netherlands. Estimates of acid production rates due to land use and acid deposition (anthropogenic sources) were made by using and interpreting literature data. It is shown that the relative contribution of the proton sources depends upon the ecosystem. Natural proton production predominates in calcareous soils, irrespective of the land use. Anthropogenic proton production is most important in non-calcareous soils. This is primarily caused by removal of biomass in agricultural soils and by acid deposition in forest soils.  相似文献   

Utilization of the genetic resources of wild species to create a nontransgenic high flavonoid tomato     

Willits MG  Kramer CM  Prata RT  De Luca V  Potter BG  Steffens JC  Graser G 《Journal of agricultural and food chemistry》2005,53(4):1231-1236

Flavonoids represent a large and important group of plant natural products that are ubiquitous in the plant kingdom. Epidemiological studies have shown the health benefits of a diet high in flavonoids. However, the dietary intake of flavonoids in most western populations is limited, creating a need to find alternative food sources for these polyphenolic secondary metabolites. The domestication of many of our cultivated food crops has resulted in alterations in the biosynthetic pathways of many essential micronutrients and vitamins through inadvertent counterselection against nutritional traits in favor of agronomic ones. Flavonoids are nearly absent from fruits of cultivated tomato (Lycopersicon esculentum Mill.), a major vegetable in human diets. Previous attempts to restore the flavonoid pathway in tomato fruits have been limited to transgenic strategies, suggesting that the problem was intractable through traditional methods. Here, we describe for the first time a nontransgenic metabolic engineering approach to developing a high flavonoid tomato using a wild tomato species (Lycopersicon pennelliiv. puberulum) and demonstrate the opportunities for restoring functional pathways using the genetic resources of wild species, resulting in production of healthier foods.  相似文献