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61.
Journal of Plant Diseases and Protection - Electron microscopy studies were carried out to investigate the association of visible disease symptoms with ultrastructural changes in barley plants...  相似文献   
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Changes in P fractions using Hedley's sequential fractionation of organic and inorganic soil P, were studied in soils covering a wide range of developmental stages and original materials. A greenhouse experiment was performed in order to make an exhaustive P uptake by Lolium perenne and to study soil phosphorus mobilization from different fractions. Samples were obtained at 30, 60 and 90 days from sowing, with two fertilization rates added as KH2PO4. The exhaustion produced by plants resulted in different patterns of mobilization according to soil characteristics. For control soils the contents of inorganic labile fraction (LIP) decreased at the end of the experience in Mollisol (31%), Vertisol (24%) and Andisol (17%). The mobilization of organic P was greater for Ultisol and Andisol (77 and 75% respectively) than for the other soils. Fertilization affected mainly inorganic P, with a significant increase in contents of LIP in Entisol (46%) and moderately resistant inorganic P (MRIP) in Andisol (15%). Inorganic P/organic P relationship tended to increase during the experiment, while labile P/moderately resistant P increased in Entisol and Mollisol.  相似文献   
64.
Replacement of fish meal (FM) and oil (FO) by plant sources can alter the feed mineral profile. However, requirements of these nutrients have not been established for gilthead sea bream. The aim of the present study was to obtain information about the adequate levels of some of these minerals (such as Zn, Cu, Mn, Se, Co, Fe and Ca) in diets with low FM and FO levels. Six plant‐based practical diets were supplemented with increasing levels of a multi‐nutrient package for 155 days. Performance parameters, biochemical analyses of whole body, vertebrae, plasma and blood cells; haematocrit; expression of several genes in liver and vertebrae were conducted. Increasing multi‐nutrient package affected fish growth, expression of molecular markers and mineral content in different tissues. A regression method was used to establish a relation between multi‐nutrient package levels and different indicators. However, nutrient interactions made it difficult to obtain clear results and so specific effects of each mineral must be studied in more detail. Mineral supplementation was required for Zn, Cu, Mn, Se and Co, whilst basal levels of Ca were sufficient to cover the optimum levels. On the other hand, there is evidence regarding a possible interaction between Fe and Zn which reduced Fe availability and absorption.  相似文献   
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In this study we investigated the effect of an ethanolic extract of propolis, with and without CAPE, and some of its components on cyclooxygenase (COX) activity. Propolis (0.00003-0.03%) significantly and concentration-dependently inhibited COX activity from lung homogenate of saline- or LPS-treated rats. Same results were obtained with CAPE (0.1-100 microM). COX activity from lung homogenate of saline- or LPS-treated rats was also inhibited by galangin (0.1-100 microM), although the inhibition induced by the lowest concentration was not significant. Caffeic, ferulic, cinnamic and chlorogenic acids and pinocembrin, (0.1-100 microM) did not affect COX activity. The inhibition curves showed that CAPE and propolis were equipotent inhibitors, whereas galangin was significantly (P<0.001) less potent than propolis and CAPE. In order to better investigate the role of CAPE, we tested the action of an ethanolic extract of propolis (0.00003-0.03%) without CAPE. This extract significantly and concentration-dependently inhibited COX activity from lung homogenate of saline- or LPS-treated rats, however, it resulted to be approximately 10 times less potent than the extract containing CAPE. The analysis of the inhibition curves of the extract with and without CAPE showed a significant (P<0.001) difference. These results suggest that both CAPE and galangin contribute to the overall activity of propolis, CAPE being more effective.  相似文献   
67.
The structural characteristics of the lignins from flax (Linum usitatissimum) fibers and shives were studied. Significant differences in the content and composition of the lignin from both parts were observed. The lignin contents were 3.8% in the fibers and 29.0% in the shives. Analysis by Py-GC/MS indicated a H:G:S molar ratio of 13:72:15 in the milled wood lignin (MWL) isolated from flax fibers and a molar ratio of 5:87:8 in the MWL isolated from flax shives. In addition, 2D-NMR showed a predominance of β-O-4' aryl ether linkages, followed by β-5' phenylcoumaran and β-β' resinol-type linkages in both MWLs, with a higher content of condensed linkages in flax shives. Thioacidolysis (followed by Raney nickel desulfurization) gave further information on the lignin units involved in the different linkages and confirmed the enrichment of G units. The thioacidolysis dimers released were similar from both lignins, with a predominance of the β-5' followed by β-1' and 5-5' structures.  相似文献   
68.
The purpose of this study was to develop operationally important soil quality indicators to evaluate long-term sustainability, at the farm scale, for no-tillage systems in Argiudolls of rolling pampa (Argentina). The soil was classified as series Arroyo Dulce (Typic Argiudoll), a fertile dark, deep and well-drained soil of the hills. Three situations were considered: pristine soil with grass vegetation, grassland soil (also considered as a reference situation); and 15 years no-tillage soils from four production plots. Physical, physico-chemical, chemical and biochemical indicators were considered. Data were analyzed by principal components analysis (PCA) with canonical discriminant analysis (CDA). The first three components explained 90% of the overall variation. For pristine undisturbed soil, the main variables selected by PCA were particulate C, pH, respiration and total organic C, and in the case of grassland they were C stock (mass of C in the 0–10 cm soil horizon), water-soluble C, and % silt. The no-tillage area was separated in different plots according to the degree of erosion with different depths of the A horizon. Clay content and bulk density were the main variables in the less degraded no tillage plots. Cluster analysis was applied to construct an average linkage distance dendrogram.  相似文献   
69.
Journal of Pest Science - The protection of reforested areas against the large pine weevil Hylobius abietis is one of the greatest forest management challenges in many European countries. No...  相似文献   
70.
Banana streak viruses (BSV) belong to the genus Badnavirus of the family Caulimoviridae. They cause banana streak disease on banana and plantains worldwide. The recent detection of BSV in Cuba has prompted a nationwide research effort focused on the occurrence, prevalence and diversity of BSV species on dessert type banana on the island. Indexing by multiplex immunocapture-PCR (M-IC-PCR) performed on samples collected throughout the country showed that the overall prevalence of Banana streak OL virus, Banana streak GF virus and Banana streak IM virus is low in Musa acuminata genotypes in Cuba. However, the prevalence of BSV species Mysore (BSMYV) was surprisingly high in samples of cv Yangambi km5 collected from distinct and distant locations. The presence in Cuba of an as yet unreported BSV species was also investigated, showing that Banana steak VN virus is also present in Musa acuminata genotypes.  相似文献   
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