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61.
Oliana Carnevali Maria Claudia Zamponi Roberto Sulpizio Arianna Rollo Miria Nardi Carla Orpianesi Stefania Silvi Massimo Caggiano Alberta Maria Polzonetti Alberto Cresci 《Aquaculture International》2004,12(4-5):377-386
Two bacterial strains Lactobacillus fructivorans (AS17B), isolated from adult sea bream (Sparus aurata) gut, and Lactobacillus plantarum (906), isolated from human faeces, were administered contemporaneously, during sea bream development using Brachionus plicatilis and/or Artemia salina and dry feed as vectors. The probiotic treatment influenced gut colonization: at 35 days post-hatching (p.h.) L. fructivorans was not present in the gut, but the treatment induced colonization by L. plantarum. At 66 days p.h., L. fructivorans was evident also in the control; moreover, when suitable environmental conditions appeared in the post-metamorphosis gastro-intestinal tract, competition between L. plantarum and L. fructivorans occurred. At 90 days p.h., L. plantarum was displaced by L. fructivorans that became significantly higher with respect to the control. In treated groups, probiotic administration significantly decreased larvae and fry mortality. 相似文献
62.
Stauder M Papetti A Mascherpa D Schito AM Gazzani G Pruzzo C Daglia M 《Journal of agricultural and food chemistry》2010,58(22):11662-11666
In previous studies we demonstrated that green and roasted coffee contains low molecular weight (LMW) compounds capable of inhibiting the ability of Streptococcus mutans, the major causative agent of human dental caries, to adhere to hydroxyapatite (HA) beads. This study addressed the ability of the whole high molecular weight coffee fraction (cHMW) and of its melanoidin and non-melanoidin components (GFC1-5), applied at concentrations that occur in coffee beverages, to (i) inhibit S. mutans growth; (ii) affect S. mutans sucrose-dependent adhesion to and detachment from saliva-coated HA beads (sHA); and (iii) inhibit biofilm development on microtiter plates. The results indicated that only cHMW is endowed with antimicrobial activity. The cHMW fraction and each of the five GFC components inhibited S. mutans adhesion, the strongest effect being exerted by cHMW (91%) and GFC1 (88%). S. mutans detachment from sHA was four times greater (~20%) with cHMW and the GFC1 and GFC4 melanoidins than with controls. Finally, biofilm production by S. mutans was completely abolished by cHMW and was reduced by 20% by the melanoidin components GFC2 and GFC4 and by the non-melanoidin component GFC5 compared with controls. Altogether these findings show that coffee beverage contains both LMW compounds and HMW melanoidin and non-melanoidin components with a strong ability to interfere in vitro with the S. mutans traits relevant for cariogenesis. 相似文献
63.
The effect of footrot on body weight and wool growth of sheep 总被引:1,自引:0,他引:1
Body weight and traits associated with production of wool were measured over a 2-year period between 1985 and 1987 in south-western New South Wales in a flock of Merino wethers experimentally infected with footrot. The disease was allowed to spread freely amongst 150 of the flock but kept at very low prevalence in the remaining 50 by preventive footbathing during transmission periods. Severe, underrunning footrot had a significant adverse effect on body weight, for each year of the trial. Body weight was most severely reduced at times of the year when footrot was spreading among animals and lesions were severe. The mean body weight of the infected group at the end of the 2 years of observation was 7.3 kg (11.6%) below that of the control group. Footrot also depressed wool growth, with the mean clean fleece weight of the infected group being 0.4 kg (8%) lighter than that of the controls at each of the 2 annual shearings. There were no consistent differences between the groups for the other wool characteristics measured. 相似文献
64.
Neospora caninum is a protozoon that causes abortion in cattle and neuromuscular lesions in dogs, with the formation of cysts mainly in the central nervous system. Since N. caninum is an intracellular parasite with tropism for the cells of nervous system, this study evaluated the respiratory metabolism of glial cells infected by this* parasite. Glial cultures obtained from the cerebral cortex of newborn rats were kept in DMEM enriched with 10% fetal bovine serum, 1 mM pyruvic acid and 2 mM of L-glutamine. They were infected at a ratio of approximately 1:1 (cell/parasite). Oxygen consumption was evaluated by polarography in the non infected and N. caninum infected groups, 24 and 72 h following infection. Glial cell respiration after 24 and 72 h was 307.2 +/- 34.7 and 308.9 +/- 64.1 microL of oxygen per mug of total protein per minute, and 566.2 +/- 54.6 and 579 +/- 117.5 microL O2/microg of total protein/minute in the control and infected groups, respectively. These results show that N. caninum does not interfere with glial respiration in vitro. 相似文献
65.
C. Fortes Ferreira M. Gonzaga Pereira A. da Silva dos Santos R. Rodrigues R.E. Bressan-Smith A. PioViana R. Figueiredo Daher 《Euphytica》2003,134(1):43-46
Among the main causes of poor yield in common beans are fungal, viral and bacterial diseases. Common bacterial blight, caused
by Xanthomonas axonopodis pv. phaseoli (Xap), is one of the major bacterial diseases leading to significant losses in Brazil. Chemical control is ineffective, therefore,
the use of resistant varieties becomes an interesting alternative. The objective of the present work was to evaluate disease
resistance under natural infection of the pathogen in 109 recombinant inbred lines (F7) of P. vulgaris originated from the cross HAB-52 (susceptible — snapbean) × BAC-6 (resistant — common bean) in two different environments,
as well as to calculate genetic parameters to assist in the selection of promising materials to be used in the CBB resistance
breeding program. The data of the genetic parameters were
compared to those calculated for the F3 generation originated from the same cross. The heritability results for DI (disease index) and VI (variation index) in F3 were 26.85% and 0.26, respectively, whereas in F7 they were 91.77% and 1.36, respectively. These results demonstrate a potential to be explored for this advanced population,
that in the future, along with other pathogen variability studies and tests in other environments, may provide more information
regarding a more precise evaluation of promising genotypes to be used in common bean breeding programs aiming to obtain CBB
resistant varieties.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
66.
Itamar Cristiano Nava Carla Andréa Delatorre Ismael T. de Lima Duarte Marcelo Teixeira Pacheco Luiz Carlos Federizzi 《Euphytica》2006,148(3):353-358
Summary Aluminum toxicity due to the cation Al+3 is a major factor limiting yields in acid soils. Wide genetic variability to aluminum tolerance is found in oat genotypes. The objectives of this study were to determine the number of genes controlling aluminum tolerance in oats and to verify if any detrimental effects were present of the aluminum tolerance genes on grain yield and grain quality in Al+3free soils. Aluminum tolerance was estimated as the average regrowth of the main root after exposure to toxic levels of Al+3 in a hydroponic solution under controlled conditions. The number of genes controlling that trait was estimated from the distribution of the average root regrowth frequencies in a population of 333 recombinant inbred lines (RIL's) in generations F5:6 and F5:7. The effects on grain yield and grain quality were assessed in a subpopulation of 162 RIL's chosen based on their aluminum tolerance response. Aluminum tolerance in the evaluated population was controlled by one dominant major gene with the tolerant genotypes carying Al
a
Al
a
and the sensitive ones al
a
al
a
alleles. No detrimental effects of the Al
a
allele on grain yield or grain quality were detected.Part of the Master of Science dissertation of the first author 相似文献
67.
M.A. Rodrigues A. Pereira J.E. Cabanas L. Dias J. Pires M. Arrobas 《European Journal of Agronomy》2006,25(4):328-335
The current increase in the organic agriculture segment has created a new market for fertilisers permitted for use in organic farming. Off-farm N sources for organic farming are scarce, considering the restriction on the use of chemical fertilisers. Thus, when some products are permitted in organic agriculture, commercial opportunities become available. In this study we compare the performances of Vegethumus (Veg) and Phenix (Phe), two manures that are permitted in organic farming, with several other manures, ammonium nitrate (AN) and control treatments. A 3-year field trial and a pot experiment were carried out in order to estimate dry matter yield, N uptake, and N nutritional status of the crops, as well as soil N availability, the latter was assessed by using anion exchange membranes inserted into the soil. Apparent N recovery (ANR) values in the field trial were 6.3% and 58.2% in Veg and AN plots, respectively, after the application of 380 kg N/ha in the previous five growing seasons. In the pot experiment, the ANR of Veg and Phe, the organic amendments permitted in organic farming, were 5.0% and 13.6%, while Beiraadubo (Bei) and Nutrisoil (Nut) had ANR of 27.2% and 42.0%. The poor results of the amendments permitted in organic farming, in light of their high prices suggest that their use must be carefully considered by farmer in their fertilization strategies. 相似文献
68.
Macedo ML Damico DC Freire Md Toyama MH Marangoni S Novello JC 《Journal of agricultural and food chemistry》2003,51(10):2980-2986
This study describes the purification of an N-acetylglucosamine-binding lectin from Koelreuteria paniculata seeds and its effects on the larval development of Callobruchus maculatus and Anagasta kuehniella. The lectin (KpLec) was characterized and isolated by gel filtration, affinity column, and reverse phase chromatography. SDS-PAGE indicated that this lectin is a dimer composed of subunits of 22 and 44 kDa. The N terminus exhibited 40% similarity with Urtiga dioica agglutinin. KpLec was tested for anti-insect activity against C. maculatus and A. kuehniella. With regard to C. maculatus, an artificial diet containing 0.7 and 1% KpLec produced LD(50) and ED(50) value, respectively. However, for A. kuenhiella, an artificial diet containing 0.65% KpLec produced an LD(50), whereas 0.2% KpLec produced an ED(50). The transformation of genes coding for this lectin could be useful in the development of insect resistance in important agricultural crops. 相似文献
69.
The antihyperglycemic effects of chemically synthesized d-chiro-inositol (d-CI), a component of an insulin mediator, have been demonstrated in rats. Buckwheat contains relatively high levels of d-CI: thus, it has been proposed as a source of d-CI for reducing serum glucose concentrations in diabetics. The present study evaluates the effects of a buckwheat concentrate, containing d-CI, on hyperglycemia and glucose tolerance in streptozotocin (STZ) rats. In fed STZ rats, both doses of the buckwheat concentrate (containing 10 and 20 mg of d-CI/kg of body weight) were effective for lowering serum glucose concentrations by 12-19% at 90 and 120 min after administration. Findings from this study demonstrate that a buckwheat concentrate is an effective source of d-CI for lowering serum glucose concentrations in rats and therefore may be useful in the treatment of diabetes. 相似文献
70.
Jose Maria da Silva Paulo Cezar Rezende Fontes Carla do Carmo Milagres July Anne Amaral de Abreu 《Journal of plant nutrition》2020,43(18):2833-2843
Abstract Adequate plant nutrition is important to reduce costs and increase the crop yield. This study tried to verify the influence of Nitrogen (N) on plant biomass production and the yield of bell pepper grown in SLAB; quantify the N use efficiency (NUE), and to quantify the residual N concentration in the substrate after the end of the crop cycle. The experiment was carried out in a protected environment. Pepper seedlings were transplanted to SLAB bags containing 40?dm3 of substrate. The treatments consisted of six N rates (0, 1.5, 3.0, 4.5, 6.0, and 7.5?g plant?1) split into 10 fortnightly applications, in a randomized block design with four replications. The fruit yield was evaluated throughout the experiment and after the final harvest, the dry mass of leaves, stem, and root of the plant, the N content and accumulated, the residual nitrate and ammonium in the substrate, and the NUE were evaluated. The rate of 5.51?g plant?1 of N, corresponding to 355.5?kg ha?1, provided the maximum yield of commercial fruits of 1.57?kg plant?1 or 101.2 t ha?1. With increasing N rate, the residual nitrate concentration in the substrate increased and the NUE decreased. 相似文献