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41.
Recent studies have indicated that plant growth-promoting bacteria (PGPB) can improve revegetation of arid mine tailings as measured by increased biomass production. The goals of the present study were first to evaluate how mode of application of known PGPB affects plant growth, and second to evaluate the effect of this inoculation on rhizosphere microbial community structure. PGPB application strategies investigated include preliminary surface sterilization of seeds (a common practice in phytoremediation trials) followed by a comparison of two application methods; immersion and alginate encapsulation. Results with two native desert plant species, Atriplex lentiformis and Buchloe dactyloides, suggest that seed surface sterilization prior to inoculation is not necessary to achieve beneficial effects of introduced PGPB. Both PGPB application techniques generally enhanced plant growth although results were both plant and PGPB specific. These results demonstrate that alginate encapsulation, which allows for long-term storage and easier application to seeds, is an effective way to inoculate PGPB. In addition, the influence of PGPB application on B. dactyloides rhizosphere community structure was evaluated using PCR-DGGE (denaturing gradient gel electrophoresis) analysis of bacterial DNA extracted from rhizosphere samples collected 75 d following planting. A comparative analysis of DGGE profiles was performed using canonical correspondence analysis (CCA). DGGE-CCA showed that rhizosphere community profiles from PGPB-inoculated treatments are significantly different from both uninoculated tailings rhizosphere profiles and profiles from the compost used to amend the tailings. Further, community profiles from B. dactyloides inoculated with the best performing PGPB (Arthro Mix) were significantly different from two other PGPB tested. These results suggest that introduced PGPB have the potential to influence the development of the rhizosphere community structure found in plants grown in mine tailings.  相似文献   
42.
The objective of this study was to confirm that weight loss after treatment with mitratapide (Yarvitan®) is loss of adipose tissue. Obese dogs were treated with the recommended treatment schedule of mitratapide. Dual-energy X-ray absorptiometry (DEXA) was done before and after the treatment schedule. Body weight, feed consumption and pelvic circumference were recorded and a glucose tolerance test was performed. Dual-energy X-ray absorptiometry measurements showed an impressive loss of fat tissue, corresponding to a mean loss of approximately 41.6% of the body fat mass recorded before treatment. After treatment with mitratapide, the mean body fat percentage had returned within the normal range. At the end of the study, the dogs had lost on average 14.2% of their body weight and 15.2% of their pelvic circumference compared to baseline. The results also suggest that losing weight with mitratapide might help to reverse insulin resistance.  相似文献   
43.
We conducted a 1-year greenhouse experiment to assess the impact of nutrient manipulations on seedling growth, biomass partitioning, and leaf gas exchange between two fast growing Pinus taeda clones that differed in growth efficiency. After 1 year we observed significant treatment and treatment by clone effects on growth, biomass partitioning, and gas exchange parameters. Fertilization increased total seedling biomass 18% primarily through an increase in foliage and coarse-roots. Clones did not differ in total seedling biomass, however, clone 85 produced more stem than clone 93 leading to 37% greater stem:leaf, while clone 93 maintained more branch biomass. The logging residue treatment increased stem:leaf by 30%, but had no effect on total biomass or partitioning. Differences in leaf morphology resulted in significantly greater canopy leaf area in clone 93 than clone 85. Increased foliar N concentration from fertilization had only minor effects on specific photosynthesis under saturating light (ASat), but lowered stomatal conductance (gs), transpiration (E), and internal to external CO2 concentration ratio (Ci/Ca) as well as improved water use efficiency (WUE) independently of genotype. When gas exchange data was scaled to the canopy level both genotypes achieved similar canopy level CO2 assimilation rates, but our data suggests they did this by different means. Although we did see a small effect of nutrient limitations in total canopy photosynthesis under saturating light (ACanopy), ASat, and total leaf area (TLA), our foliar N concentration ([N]) indicated that our level of logging residue incorporation did not cause [N] to decrease below sufficiency limits. From a practical standpoint, a better understanding of strategies for capturing and partition C may lead to better selection of clonal material, thereby, optimizing productivity.  相似文献   
44.
45.
Two Safflower (Carthamus tinctoriusL.) cultivars' seeds were used to study the influence of inoculation with mycorrhiza arbuscular fungi under salinity stress condition. Factorial experiment based on completely randomized design (three-way analysis of variance (ANOVA)) with 3 replications was used. Salinity treatment with 3 levels (0.5, 6, and 12 dS/m) and mycorrhizal arbuscular inoculation with two species (three levels consist of non-inoculation, and inoculation with Glomus intraradices and G. moseae) were applied on two cultivars of safflower (Goldasht and Padide) in this experiment. Some important biochemical, mineral, and growth traits were measured in this study. Salinity had a significant negative effect on all growth and morphological parameters including shoot and root dry weight, stem and root height. On the other hand, colonized plants showed better growth parameters under saline conditions compared with the control. The colonization of both mycorrhizal species decreased with salinity. Sugar and pigment content decreased with salinity, but their levels in colonized plants under saline conditions were higher than that in non-colonized plants. Mineral elements including phosphorus (P), nitrogen (N), and magnesium (Mg) were higher in colonized plants, while salinity decreased the absorption of these elements in both inoculated and non-inoculated plants. Higher activity of the enzymatic antioxidant means higher removal of these compounds and higher resistance to stress condition. Overall, it is clear that salinity had a negative effect on both cultivars of safflower, but these negative effects were lower in inoculated plants than in the non-inoculated ones; so, the use of mycorrhizal inoculation is a proper way to control the effect of salinity and maintain plant production.  相似文献   
46.

Background  

Animals, including humans, exhibit a variety of biological rhythms. This article describes a method for the detection and simultaneous comparison of multiple nycthemeral rhythms.  相似文献   
47.
In the Spring of 2009, a veterinarian reported suspected classical swine fever (CSF) on a multiplier pig farm in the southern part of The Netherlands (close to the Belgian border). Over a 5-week period there had been a number of sick sows and an excessively high percentage of stillborn and preterm piglets. Sick animals were treated with anti-inflammatory drugs and antibiotics, but did not respond as well as anticipated. A visiting specialist team from the Food Safety Authority could not exclude CSF as the cause of the clinical problems and sent blood samples to the reference laboratory in Lelystad for a PCR test on CSF antigen. Fortunately, test results obtained 6 hours later were negative for CSF, and the disease control measures were lifted. It later appeared that porcine reproductive and respiratory syndrome (PRRSV) might have been responsible for the problems. But what if CSF had caused the clinical problems? A CSF-transmission model was used to simulate CSF outbreaks dependent on the duration of the high-risk period (HRP). As the duration of the HRP increased, there was an exponential growth in the number of pig farms infected during this period. Simulations also showed that with a longer HRP, the virus spread over greater distances from the source herd. It was also investigated whether a possible CSF outbreak could be detected on the basis of an increased mortality and hence increased number of cadavers sent to a rendering plant. However, the calculated mortality incidence was not sensitive enough to serve as an alarm signal. It is recommended that CSF-exclusion diagnostics be used much earlier in similar clinical situations on pig farms.  相似文献   
48.
For coniferous gymnosperms, few data exist as to the contribution of the membrane-associated proteome to cell wall and wood formation. In this study, we begin to address this knowledge deficiency by examining the proteomic profile of Golgi-enriched membrane preparations derived from developing Pinus radiata compression wood. These membrane preparations were generated by a combination of discontinuous sucrose gradient centrifugation and Triton X-114-based phase separation. Fractionation by phase separation removed contaminating proteins associated with the cytoskeleton and enabled the discrimination between soluble and membrane-bound/integral proteins. The proteomic analysis of the resulting aqueous and detergent phases using high-performance liquid chromatography-tandem mass spectrometry resulted in the identification of 175 proteins. The majority of the identified proteins were membrane bound/integral and originated from cellular components such as the nucleus, plastids, endoplasmic reticulum, plasma membrane and Golgi vesicles. On the basis of bioinformatic analysis, many of the identified proteins were predicted to be involved either in the regulation of wood formation or in cell wall biosynthesis, which indicated that the proteomic analysis of non-cytosolic proteins in developing xylem is a useful strategy to investigate the molecular aspects of wood formation in pine.  相似文献   
49.

Background  

Samples for plant metabolic fingerprinting are prepared generally by metabolism quenching, grinding of plant material and extraction of metabolites in solvents. Further concentration and derivatisation steps follow in dependence of the sample nature and the available analytical platform. For plant material sampled in the field, several methods are not applicable, such as, e.g., collection in liquid nitrogen. Therefore, a protocol was established for sample pre-treatment, grinding, extraction and storage, which can be used for analysis of field-collected plant material, which is further processed in the laboratory. Ribwort plantain (Plantago lanceolata L., Plantaginaceae) was used as model plant. The quality criteria for method suitability were high reproducibility, extraction efficiency and handling comfort of each subsequent processing step.  相似文献   
50.
The hypothesis of the present study was that a GnRH agonist application at early pregnancy would alter the pattern of the key reproductive hormones LH and FSH, and subsequently that of estradiol (E2) and especially progesterone (P4), and improve the conditions for embryo survival in early pregnant gilts. Therefore, the endocrine effects of a GnRH agonist (GnRHa) application to gilts (n=11 GnRHa treated, n=9 saline Controls) were studied in blood samples from the Vena cava caudalis. GnRHa injected on Day 12 after insemination induced elevated (P<0.01) LH and FSH levels for at least 180 min. However, subsequent LH concentrations were not altered up to Day 21 of pregnancy. LH pulse number, estimated in 6-h period samples on Days 13, 15 and 17, was not influenced by treatment and pregnancy. LH pulse amplitude was decreased (P<0.05) on Days 13 to 17 in pregnant gilts of both groups, but not in nonpregnant animals. In pregnant GnRHa-treated gilts, the basal LH level was elevated compared with the Controls (P<0.01). Additionally, differences (P<0.05) in basal LH were present between the pregnant and nonpregnant animals. The P4 and E2 secretion pattern was not affected by GnRHa. P4 concentrations increased (P<0.01) from Day 10 to Day 14 regardless of the treatment. P4 revealed a pulse-like pattern, but without a definite relation to the LH pulse characteristics. Also, pregnancy rate (73 vs. 67%) and the number of fetuses (12.8 ± 2.3 vs. 11.6 ± 2.3) were unaffected in the treated and Control gilts, respectively. The present study did not confirm the initial hypothesis that a GnRHa-mediated LH effect could alter ovarian steroid secretion and favorably support early embryo development and pregnancy outcome.  相似文献   
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