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991.
Ferreres F Valentão P Llorach R Pinheiro C Cardoso L Pereira JA Sousa C Seabra RM Andrade PB 《Journal of agricultural and food chemistry》2005,53(8):2901-2907
Glycosylated kaempferol derivatives from the external leaves of tronchuda cabbage (Brassica oleracea L. var. costata DC) characterized by reversed-phase HPLC-DAD-MS/MS-ESI were kaempferol 3-O-sophorotrioside-7-O-glucoside, kaempferol 3-O- (methoxycaffeoyl/caffeoyl)sophoroside-7-O-glucoside, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-sophorotrioside-7-O-sophoroside, kaempferol 3-O-sophoroside-7-O-sophoroside, kaempferol 3-O-tetraglucoside-7-O-sophoroside, kaempferol 3-O-(sinapoyl/caffeoyl)sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl/caffeoyl)sophoroside-7-O-glucoside, kaempferol 3-O-sophorotrioside, kaempferol 3-O-(sinapoyl)sophoroside, kaempferol 3-O-(feruloyl)sophorotrioside, kaempferol 3-O-(feruloyl)sophoroside, kaempferol 3-O-sophoroside, and kaempferol 3-O-glucoside. These acylated derivatives are reported for the first time in nature, with the exception of kaempferol 3-O-(sinapoyl)sophoroside. Quantification of the identified compounds was achieved by HPLC-DAD and carried out in samples cultivated under conventional or organic practices and collected at different times. In general, samples from organic production exhibited higher total phenolics content than those from conventional practices collected in the same period. 相似文献
992.
Sousa C Valentão P Rangel J Lopes G Pereira JA Ferreres F Seabra RM Andrade PB 《Journal of agricultural and food chemistry》2005,53(23):9128-9132
A phytochemical study was undertaken on tronchuda cabbage (Brassica oleracea L. var. costata DC) cultivated under conventional and organic practices and collected at different times. Six organic acids (aconitic, citric, ascorbic, malic, shikimic, and fumaric acids) were identified and quantified by HPLC-UV. Qualitative and quantitative differences were noted between internal and external leaves. Analysis of the phenolics of the internal leaves was achieved by HPLC-DAD, and the phenolic profile obtained was revealed to be distinct from that of the external leaves. By this means were identified and quantified 11 compounds: 3-p-coumaroylquinic acid, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-(caffeoyl)sophoroside-7-O-glucoside, kaempferol 3-O-(sinapoyl)sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl)sophoroside-7-O-glucoside, kaempferol 3-O-sophoroside, two isomeric forms of 1,2-disinapoylgentiobiose, 1-sinapoyl-2-feruloylgentiobiose, 1,2,2'-trisinapoylgentiobiose, and 1,2'-disinapoyl-2-feruloylgentiobiose. In general, internal leaves exhibited more constant chemical profiles. 相似文献
993.
Cantera RG Zamarreño AM García-Mina JM 《Journal of agricultural and food chemistry》2002,50(26):7609-7615
Iron deficiency is a common problem for many plants grown in alkaline and calcareous soils. To correct this problem, iron is supplied to plants as chelates. Several iron chelates are sold under diverse trademarks with different characteristics. This work evaluated 18 commercial products containing the most representative chelated iron sources used in agricultural practice in Spain when the study was done, namely the ferric chelates of EDDHA, EDDHMA, EDDCHA, EDDHSA, EDTA, and DTPA. The chelates were comprehensively characterized and quantitated by several techniques, including several chromatographic methods. Iron and chelate dynamics in soil were also studied in a model alkaline and calcareous soil. Results indicate that, in this model soil, among the different iron compounds studied only FeEDDHA and analogues have the capacity to maintain soluble iron in soil solution over time. These results are in agreement with general experience under field conditions. Furthermore, among the different ortho-ortho isomers of FeEDDHA's, FeEDDHSA and FeEDDCHA showed greater capacity than FeEDDHA and FeEDDHMA to maintain the chelated iron in soil solution over time. 相似文献
994.
995.
Paixão Pedro Thiago Medeiros Nascimento Ana Carolina Campana Nascimento Moysés Azevedo Camila Ferreira Oliveira Gabriela França da Silva Felipe Lopes Caixeta Eveline Teixeira 《Euphytica》2022,218(4):1-9
Euphytica - Head splitting is a major physiological disease in cabbage. The most effective approach for controlling head splitting is to deploy genetic resistance by breeding cabbage cultivars with... 相似文献
996.
Baozhong Zhang Yu Liu Di Xu Nana Zhao Bo Lei Ricardo D. Rosa Paula Paredes Teresa A. Paço Luis S. Pereira 《Irrigation Science》2013,31(6):1303-1316
An accurate estimation of crop evapotranspiration (ET c) is very useful for appropriate water management; hence, an accurate and user-friendly model is needed to support related irrigation decisions. In this view, a study was developed aimed at estimating the ET c of winter wheat–summer maize crop sequence in the North China through eddy covariance measurements, to calibrate and validate the SIMDualKc model, to estimate the basal crop coefficients (K cb) for both crops and to partition ET c into soil evaporation and crop transpiration. Two years of field experimentation of that crop sequence were used to calibrate and validate the SIMDualKc model and to derive K cb using eddy covariance measurements. Various indicators have shown the goodness of fit of the model, with estimated values very close to the observed ones and estimate errors close to 0.5 mm d?1. The initial, mid-season and end basal crop coefficients for wheat were 0.25, 1.15 and 0.30, respectively, and those for maize were 0.15, 1.15 and 0.45, thus close to those proposed in FAO56 guidelines. The soil evaporation represented near 80 % of ET c for the initial stages of winter wheat and summer maize and decreased to only 5–6 % during the mid-season period. Evaporation during the full crop season averaged 28 % for winter wheat and 40 % for summer maize. The importance of wetting frequency and crop ground coverage in controlling soil evaporation was evidenced. 相似文献
997.
A. I. Gusmão Lima S. I. A. Pereira E. M. de Almeida Figueira G. C. N. Caldeira H. D. Q. Caldeira 《Journal of plant nutrition》2013,36(12):2165-2177
ABSTRACT The present work was designed to analyze cadmium (Cd) accumulation in Pisum sativum L. plants in a late stage of development, after an exposure to environmentally relevant Cd concentrations of 1, 3, and 30 μ mol L? 1 Cd. Cadmium exposure increased metal and thiol accumulation, not only in roots but also in the aerial organs of the plants. Nonetheless, except for the highest Cd exposure, plants did not show any evidence of Cd toxicity symptoms. Roots were found to be the main organs for Cd accumulation, but seeds also retained Cd, accumulating up to 2 μ g Cd g fw? 1. The parameters related to reproduction, such as anthesis and fruit development, were more sensitive to incipient degrees of stress than the biomass gain itself. When compared to previous works using hydroponic cultures, our results evidenced striking differences in Cd and thiol accumulation, suggesting the importance of using more realistic conditions in Cd-stress studies. The analysis of Cd retention in fruits demonstrated that, even at the lower exposure, Cd levels were higher than those allowed for human consumption, hence posing a serious risk of food-chain transfer and confirming the need for more studies on Cd accumulation in contaminated soils. 相似文献
998.
Fábio Luiz Partelli Henrique Duarte Vieira Valério Bertolasse de Carvalho Francisco de Assis Alves Mourão Filho 《Journal of plant nutrition》2013,36(10):1651-1667
ABSTRACT The objective of this work was to establish and compare Diagnosis and Recommendation Integrated System (DRIS) norms with the sufficiency range approach, and apply these methods on nutritional diagnosis of Arabian coffee, in field samples collected in summer and winter in Southern Brazil. DRIS norms and sufficiency range were established in groves with average biennial yield equal or above 3000 kg ha? 1. The “t” test was used to verify the differences between the sufficiency range and the DRIS norms. The foliar concentrations of nitrogen (N), phosphorus (P), and sulfur (S) were higher in summer, and iron (Fe), and manganese (Mn) in winter. The reference values should be specific for the period of the year. There were differences in the foliar nutritional diagnosis, between the DRIS method and the sufficiency range approach. In samples during the summer analyzed with DRIS, copper (Cu), S, potassium (K), and zinc (Zn) were considered more limited nutrients and Mn, S, K, and calcium (Ca) when the sufficiency range was used. 相似文献
999.
N. K. Fageria A. B. Santos M. P. Barbosa Filho C. M. Guimarães 《Journal of plant nutrition》2013,36(9):1676-1697
Lowland rice is a staple food for more than 50% world population. Iron toxicity is one of the main nutritional disorders, which limits yield of lowland rice in various parts of the world. The toxicity of iron is associated with reduced soil condition of submerged or flooded soils, which increases concentration and uptake of iron (Fe2 +). Higher concentration of Fe2 + in the rhizosphere also has antagonistic effects on the uptake of many essential nutrients and consequently yields reduction. In addition to reduced condition, increase in concentration of Fe2 + in submerged soils of lowland rice is associated with iron content of parent material, oxidation-reduction potential, soil pH, ionic concentration, fertility level, and lowland rice genotypes. Oxidation-reduction potential of highly reduced soil is in the range of –100 to –300 mV. Iron toxicity has been observed in flooded soils with a pH below 5.8 when aerobic and pH below 6.5 when anaerobic. Visual toxicity symptoms on plants, soil and plant tissue test are major diagnostic techniques for identifying iron toxicity. Appropriate management practices like liming acid soils, improving soil fertility, soil drainage at certain growth stage of crop, use of manganese as antagonistic element in the uptake of Fe2 + and planting Fe2 + resistant rice cultivars can reduce problem of iron toxicity. 相似文献
1000.
Elisa Sandra Tanaka de Farias José Carlos Pintro Maria Anita Gonçalves da Silva Antonio Saraiva Muniz Marlene Estevão Marchetti Antonio Nolla 《Journal of plant nutrition》2013,36(3):465-475
The objective of the present study was to evaluate the phytotoxic effect of aluminum (Al) in corn plants in nutrient solution under high ionic strength (0.0094 uM) and low ionic strength (0.00001 uM). Regarding the low ionic strengths, nutrient solution was added daily until the end of the experimental period. The findings showed that the pH of the nutrient solution reduced with the increase in Al concentration, under both high and low ionic strengths solutions. Electrical conductivity of the nutrient solution increased with Al concentrations only in the solution with low ionic strength, demonstrating that the plant was more sensible to the element toxicity, thus reducing its growth and absorption of nutrients. The production of the total dry mass of corn was affected by the increase of Al concentration in the solution only under low ionic strengths, which reinforces the greater activity and absorption of the element under such condition. 相似文献