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991.
Regina Célia Faria Simão Canesin Salatiér Buzetti Juliana Aparecida de Souza 《Journal of plant nutrition》2015,38(4):639-646
Boron (B) is transported mainly in the xylem, but by using isotopic tracers it was possible to verify that B has significant mobility in the phloem of polyols-producing species. Thus, the objective of this study was to evaluate the mobility of 10B applied to cashew plants. The experiment was conducted from 05/10 to 07/10/2010 in a greenhouse of University of São Paulo State-UNESP, Ilha Solteira Campus, State of São Paulo, Brazil. 0.5 mg of B L?1 of soil was used in the substrate. A solution of 255 mg of B L?1 was used in recently mature and fully developed leaves. The total content of B and and percentage of boron in the plant derived from fertilizer (Bppf%) were evaluated in the old and new leaves stemming at 30 and 60 days after the application of 10B. As evidenced, B applied to leaves had restricted mobility in cashew tree. However, B applied in the substrate was absorbed and translocated to young leaves. 相似文献
992.
利用恢复系 R113与10种不同细胞质的异质小麦雄性不育系 Selkirk(或Chris)杂交,以鉴定 R113对这些雄性不育系的恢复力。其中有7种细胞质的雄性不育性在不同程度上为 R113所恢复。证明了 R113恢复性的广泛性。特别值得注意的是 R113对 Ae.ovata 细胞质不育的恢复度极高,其恢复性可能由两对恢复基因控制.根据杂交种与其亲本之间以及同质 Selkirk 与异质 Selkirk 品种之间的比较,大多数所测性状,如株高、抗倒伏性、每穗小穗数、每穗粒数、每穗粒重等,在 Ae.ovata 细胞质背景下都有明显的优势.试验证明,在小麦中确实存在着两种杂种优势:即核间杂种优势和核质间杂种优势。Ae.ovata 细胞质的缺点是较晚熟,然而,延长春化时间可以提早抽穗;在其同早熟亲本杂交的后代中,也可以选出早熟植株.在小麦常规育种中或在杂种优势的利用上,可以应用 Ae.orata 细胞质把上述两种杂种优势结合起来,选育优良的小麦核质杂种品种或杂种小麦。 相似文献
993.
Granado-Lorencio F Donoso-Navarro E Sánchez-Siles LM Blanco-Navarro I Pérez-Sacristán B 《Journal of agricultural and food chemistry》2011,59(21):11819-11824
Bioactive compounds are used in the design and development of new food products with potential health benefits, although little is known regarding their bioavailability and interactions. This study assessed the stability, in vitro bioaccessibility, and human bioavailability of β-cryptoxanthin from β-cryptoxanthin-rich drinks with and without added phytosterols developed for this purpose. The developed drinks showed no difference in the content of β-cryptoxanthin, and they were stable over 6 months. In vitro, hydrolysis of β-cryptoxanthin esters and the amount of free β-cryptoxanthin at duodenal and micellar phases were similar regardless of the presence of phytosterols. In the human study, the daily intake provoked significant increments of β-cryptoxanthin in serum regardless of the type of the drink. In conclusion, in vitro and in vivo human studies have shown that the bioavailability of β-cryptoxanthin is not significantly affected by the presence of phytosterols when they are simultaneously supplied in a drink. 相似文献
994.
Andreza S. Costa Luis Carlos Nogueira Venézio F. dos Santos Fernando Luiz Finger Terezinha Rangel Camara Vivian Loges Lilia Willadino 《Postharvest Biology and Technology》2011,59(1):103-109
Inadequate temperatures during the shipping and commercialization of cut tropical flowers may accelerate the senescence process and cause chilling injury, leading to symptoms that have not yet been described for Heliconia bihai. The aim of the present study was to evaluate physiological responses in cut inflorescences of H. bihai cv. Lobster Claw (LC) and cv. Halloween (HW) as well as symptoms of senescence and chilling injury. For such, changes in fresh weight, bract color (L*, a* and b*), percentage of absolute integrity (PAI) of cell membranes and leakage of potassium ions (LPI) were determined. The flowering stems were evaluated at five different intervals after harvest (0, 2, 4, 6 and 8 d). A refrigerated treatment (RT) with a temperature of 6.5 °C and 85% relative humidity was compared to a control treatment (CT) at room temperature of 24 °C and 66% relative humidity. Both cultivars stored at 6.5 °C exhibited dryness of bract tissue (symptom of senescence) and dark stains that became brownish and evolved to necrosis (symptom of chilling injury). The visual quality of inflorescences decreased with time in both cultivars maintained without refrigeration. The severity of chilling injury increased with the length of storage time in both cultivars. There was a significant reduction in the fresh weight of inflorescences in both treatments (RT and CT) and both cultivars (LC and HW). Bract color changed in both cultivars at 6.5 °C. There was no change in PAI throughout the evaluation period in the inflorescences stored at room temperature, whereas those stored at 6.5 °C for 6 and 8 d had lower PAI values. The inflorescences in the control treatment underwent no change in LPI values, whereas those stored under refrigeration had increased LPI values after the sixth day of storage. The physiological responses of cut Heliconia flowers were influenced by storage period and temperature, as demonstrated by visual symptoms of chilling injury and senescence. 相似文献
995.
Comesaña Losada M Leão JM Gago-Martínez A Rodríguez Vázquez JA Quilliam MA 《Journal of agricultural and food chemistry》1999,47(2):618-621
Further studies on mussel samples from Galicia, Spain, have revealed the presence of okadaic acid (OA), dinophysistoxin 2 (DTX2), and the fatty acid acyl esters of both of these toxins as the "DTX3" complex. Measurements were performed with an improved in situ method for the formation of 9-anthryldiazomethane (ADAM) derivatives followed by liquid chromatography with fluorescence detection. Base hydrolysis of DTX3 toxins gave free OA and DTX2, which were determined following ADAM derivatization. Results were confirmed by liquid chromatography/mass spectrometry analyses, and in most of the samples, free DTX2 was the most abundant toxin. However, the OA/DTX2 ratio in the DTX3 conjugated form was different, with OA being the most abundant in all cases. This difference could be due to different rates of metabolism of OA and DTX2 to the acyl esters or due to contamination of the shellfish by the two toxins at different points in time, resulting in less acyl ester formation for one toxin versus the other. The second possibility would be reasonable if two different source organisms were producing the toxins. 相似文献
996.
J. A. Hernández M. S. Almansa L. del Río F. Sevilla 《Journal of plant nutrition》2013,36(12):2539-2554
Abstract Superoxide dismutase (SOD) pattern, catalase, Cyt c oxidase and fumarase activity were studied in leaves of Phaseolus vulgaris and Vigna unguiculata plants growth in two sodium chloride (NaCl) concentrations (35 mM and 100 mM). In bean plants growth with NaCl, leaf chloride (Cl?) contents were higher than in control plants, and the same was found for sodium (Na+) and potassium (K+) contents, although to a lesser degree. In cowpea leaves, Na+ and Cl? had a similar increase due to salt‐growth conditions. Under salinity, all changes in the antioxidant (SOD and catalase) enzymes levels were smaller in bean than in cowpea plants. In Phaseolus at 15 days growth, Cu, Zn‐SOD I showed an increase by the effect of salt treatment, but this induction did not occur at 30 days growth, and both Mn‐SOD and Cu, Zn‐SOD II did not show variations due to salt‐stress. In Vigna, Mn‐SOD was decreased by salinity but this was compensated by an increase in Cu, Zn‐SOD I activity in plants at 30 days growth, whereas in young leaves under saline conditions, both isozymes were also decreased. Likewise, there was a rise in cytochrome c oxidase and fumarase activity in leaves of NaCl‐treated plants compared to the control. The activity changes observed are discused in term of their possible relevance to plant sensitivity to saline conditions. 相似文献
997.
Jesus J Malpartida Pasco Jose W Carvalho Filho Carlos M de Espirito Santo Luis Vinatea 《Aquaculture Research》2018,49(1):222-231
Aeration systems used in BFT farming need to meet the dissolved oxygen demand from the biota present in the tank, as well as to keep the particulate matter in suspension. In BFT systems, it is common to use blowers, but the choice of an aerator with better efficiency in oxygen transfer and in electric energy consumption is indispensable. The vertical pump model (VPM) aerator is the most used in intensive tilapia production systems in southern Brazil. The objective of this research was to verify if this aerator model can support Nile tilapia farming under BFT system without producing negative impacts on the functionality neither of the biofloc nor in the production indexes. Simultaneous farming on BFT using blowers served as control. Oreochromis niloticus juveniles with an initial density of 7 kg/m3 were used. After 56 days of farming, the VPM aerator obtained significantly better results, both in water quality parameters and in production indexes, when compared to those obtained in the control treatment. The temperature was higher in the treatment of the blowers due to the lower thermal exchange between the atmospheric air and the tank water. Although the VPM caused lower temperatures, it obtained a productivity of 21.2 kg/m3, compared to 20.2 kg/m3 of the blowers. It was concluded that the use of the VPM aerator had no negative influence on both the formation and functionality of the biofloc, obtaining even higher production rates. 相似文献
998.
Luis Arturo Bello-Prez Paul Colonna Philippe Roger Octavio Paredes-Lpez 《Cereal Chemistry》1998,75(4):395-402
High-performance size-exclusion chromatography (HPSEC), static light scattering (SLS) and dynamic light scattering (DLS) techniques were used for the structural characterization of amaranth starch, solubilized in water by microwave heating in a high-pressure vessel. Apparent average molar mass (M w) gyration radius (R G), and hydrodynamic radius (R H) values were obtained from Berry and Zimm treatment of light-scattering data. When heating time increased from 35 to 90 sec, the M w, R G, and R H decreased, demonstrating a possible polymer degradation due to temperature. Apparent M r values from HPSEC at 35 sec (27 ± 2 × 107 g/mol) and 50 sec (20 ± 2 × 107 g/mol) were lower than those determined by SLS (35 sec = 69 × 107 g/mol, 50 sec = 56 × 107 g/mol). However, at 70 and 90 sec, the inverse pattern was obtained. The fractal dimensions (d′f) from HPSEC study for samples dissolved for 35 (3.26), 50 (3.24), and 70 sec (3.14) are characteristic of a particle that has the internal structure of hard sphere, and for samples dissolved for 90 sec (2.19), are characteristic of a fully swollen, randomly branched macromolecule. From SLS, d′f decreased with increasing treatment time (d′f = 2.44, 2.18, 1.50, and 1.03 for 35, 50, 70, and 90 sec, respectively). The particle-scattering factors and Kratky plots, well-suited for studying the internal structure of a macromolecule, showed a sample degradation when treatment time increased. Results from DLS showed bimodal distributions with differences in the peak locations when treatment time increased. The ratio of R G to R H (ρ) for samples analyzed were between 0.88 and 1.3; these values are characteristic of a sphere or globular structure. 相似文献
999.
1000.
In the southwest part of the Iberian Peninsula the dominant land-use are the Portuguese montados and Spanish dehesas, parkland
forested areas of anthropogenic origin dominated by cork oak. They form a wooded matrix with open areas, scattered woodlands
and undisturbed patches of Mediterranean forest and scrublands. The montados are characterized by a rich bird community. We
have focus our study in a multidisciplinary approach, evaluating how management and landscape patterns influence the bird
community in order to identify potential threats to its conservation. The study was conducted in the Site of Community Importance
of Serra de Monfurado were 70% of the area is cork and holm oaks. We used data from 120 10-min point counts. Using variation
partitioning, we determined the independent and joint effects of Forest, Management and Habitat variables. The variation captured
in bird assemblage was 65.06%. Most of the explained variation was related to the Habitat and Management variables. The explanatory
variables that were high-lighted as important predictors were variables that reflected tree and shrub density and cork removal.
Modelling for forest species through generalized linear models (GLM) emphasize that the management plays an important role
in the species distribution. The most important variables selected in models reflected cattle grazing and cork removal. Our
results point out that the type of management is crucial to maintain the equilibrium in bird community associated to montados.
Farmland and forest species will benefit from areas with different tree densities, small patches of Mediterranean scrubs in
the understory and correct livestock numbers. 相似文献