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1.
The eukaryotic expression plasmid of M2e-Hsp70 is a candidate M2e-based DNA vaccine. In order to evaluate the immunization potential of this construct, Specific Pathogen Free chickens were immunized either intramuscularly or orally. Mutant Salmonella typhimurium was used as carrier for oral delivery of the M2e-Hsp70 construct. M2e-specific humoral and cellular responses were tested by ELISA and Lymphocyte Proliferation Assay, respectively. Our results indicate that both humoral and cellular immune responses are conferred against M2e-Hsp70 plasmid in either of the intramuscular or oral routes of administration; however, these responses are significantly higher in intramuscular injection in contrast to oral administration. When it comes to mass vaccination of commercial chicken flocks oral administration is preferred due to the ease of application as well as its capability of eliciting mucosal, humoral and cellular immune responses; so measurements should be taken to improve the immunization potency of our orally delivered DNA vaccine.  相似文献   
2.
Attempts to phosphorylate myo-inositol with various polyphosphates or urea-phosphate under aqueous conditions proved unsuccessful, despite reports to the contrary. The easiest way to phosphorylate myo-inositol completely is to heat it with H3PO4 under reduced pressure at 150°C for 6 h.  相似文献   
3.
A pot experiment was conducted under greenhouse conditions with two subspecies of beet, fodderbeet ( Beta vulgaris cv. Majoral) and seabeet ( Beta maritima ), under saline conditions. Growth and physiological parameters (dry weight, leaf area, water relations and net photosynthesis) were recorded. The two subspecies responded differently in terms of growth parameters. Plant growth was significantly reduced at 400 m m NaCl, while no significant growth reduction occurred at 200 m m NaCl. Fairly high values of relative growth rate were associated with the leaf area of the cultivars. The water content of the shoot decreased with plant age. The fodderbeet cultivar Majoral showed a significant increase in dry matter at 200 m m NaCl after 5 weeks. This growth improvement may be related to the better adaptation of the plants under saline conditions.  相似文献   
4.
Abstract

Seed soak treatment of sunnhemp (Crotalaria juncea L.) with the systemic pesticides, benomyl, methomyl, phorate and carbofuran, gave protection against infection with tobacco mosaic virus (TMV). These chemicals significantly inhibited infection on sunnhemp plants and reduced virus infectivity, as well as delaying the appearance of systemic symptoms. Benomyl was found to be the most effective chemical.  相似文献   
5.

Purpose

This study delineated the effect of calcium (Ca) and ethylenediaminetetraacetic acid (EDTA) addition on arsenic (As) accumulation and physiological attributes of Vicia faba L.

Materials and methods

Two separate experiments were performed. In the first experiment, V. faba seedlings, grown under hydroponic conditions, were exposed to three levels of As (25, 125 and 250 μM) in the presence and absence of three levels of EDTA (25, 125, 250 μM) and calcium (CaCl2: 1, 5 and 10 mM). The effect of EDTA and Ca on As accumulation and physiological attributes of V. faba was assessed by determining As contents in roots and shoot, chlorophyll contents, H2O2 contents, and lipid peroxidation in young and old leaves. In the second experiment, V. faba seeds were grown in As-contaminated sand culture using the same treatment plan.

Results and discussion

The accumulation and toxicity of As to V. faba plants increased with increasing As levels in nutrient solution. Arsenic exposure enhanced the production of reactive oxygen species (ROS) in both roots and leaves, which resulted in lipid peroxidation and decreased chlorophyll contents. The presence of both EDTA and Ca, in general, significantly decreased As accumulation by V. faba seedlings, Ca being more effective than EDTA. Both the amendments decreased As-induced reactive oxygen species (ROS) production and lipid peroxidation. In the case of chlorophyll contents, EDTA significantly decreased chlorophyll contents, while Ca significantly increased chlorophyll contents compared to As. The effect of all the treatments was more pronounced in roots than leaves and in young leaves compared to old leaves.

Conclusions

It is proposed that EDTA and Ca greatly affect As accumulation and toxicity to V. faba, and the effect varies greatly with their applied levels as well as type and age of plant organs. The germinating seedlings of V. faba may be preferred for risk assessment studies, while transplanting 1-week-old V. faba seedlings to As-contaminated soils can decrease its toxicity.
  相似文献   
6.
The aim of this study was to reduce the breakdown of hybrid vigour by crossing maize × teosinte subspecies through induced tetraploidy and to improve the biomass and reproductive fertility of the induced tetraploids. To achieve this, seeds of maize breeding lines selected from an open‐pollinated population ‘Sargodha‐2002’ and a maize × teosinte cross were germinated in colchicine solution (0·25, 0·5 or 1·0%) until they had a thick radical and protruded plumule. Colchicine at 0·5% induced the highest number of tetraploids with the lowest number of chimeric plants. The induced tetraploids of maize and maize × teosinte crosses showed a significant ( 0·05) increase in leaf area (5 and 14%), total soluble solids (20 and 18%), leaf oil percentage (42 and 12%) and leaf crude protein contents (10 and 14%) in leaves relative to the diploid subspecies. Moreover, induced tetraploidy also arrested hybrid vigour by slowing down the decay of heterosis in progenies (4x) for plant height, leaf biomass and leaf oil percentage. Induced maize × teosinte hybrid tetraploids selected for frequent bivalent chromosome pairing resulted in higher seed setting cob?1 (increased 58%), pollen fertility (increased 59%) and seed setting percentage (increased 100%) than the quadrivalent variant.  相似文献   
7.
【目的】比较不同来源葡萄果实中叶酸积累的差异,并利用分子标记技术对高叶酸种质资源进行评价和筛选。【方法】采用ELISA技术检测22份葡萄种质资源果实叶酸含量;利用ISSR分子标记对22份葡萄种质资源进行基因组多态性分析和聚类分析;分析检测出叶酸含量与聚类结果。【结果】22份葡萄种质资源果实叶酸含量的范围在1.93~46.95 ng/g,在遗传相似系数为0.621处,22份葡萄材料明显分为2大类群。第1大类叶酸含量平均为35.79 ng/g;其余为第2大类,叶酸含量平均为15.71 ng/g。在遗传相似系数为0.622处,21份葡萄材料又明显分为2大类群。第1大类叶酸含量平均为16.53 ng/g;第2大类叶酸含量平均为12.24 ng/g。欧亚种的叶酸含量较欧美杂种稍高3.998 7 ng/g;从30条引物中筛选出9条扩增稳定且多态性丰富的引物用于葡萄的ISSR扩增。共扩增出78条条带,其中多态性条带70条,多态性百分率为89.7%。22份葡萄种质资源的遗传相似系数为0.474 4~0.846 2,平均遗传相似系数为0.654 5。在遗传相似系数为0.621处,22份葡萄材料明显分为2...  相似文献   
8.

Purpose

At the global scale, soil contamination with persistent metals such as lead (Pb), zinc (Zn), and copper (Cu) induces a serious threat of entering the human food chain. In the recent past, different natural and synthetic compounds have been used to immobilize metals in soil environments. However, the mechanisms involved in amendment-induced immobilization of metals in soil remained unclear. The objective of the present work was therefore to determine the mechanisms involved in metal-phosphates formation in the rhizospheric soils of pea and tomato currently cultivated in kitchen gardens.

Materials and methods

Pea and tomato were cultivated on a soil polluted by past industrial activities with Pb and Zn under two kinds of phosphate (P) amendments: (1) solid hydroxyapatite and (2) KH2PO4. The nature and quantities of metal-P formed in the rhizospheric soils were studied by using the selective chemical extractions and employing the combination of X-ray fluorescence micro-spectroscopy, scanning electron microscopy, and electron microprobe methods. Moreover, the influence of soil pH and organic acids excreted by plant roots on metal-P complexes formation was studied.

Results and discussion

Our results demonstrated that P amendments have no effect on metal-P complex formation in the absence of plants. But, in the presence of plants, P amendments cause Pb and Zn immobilization by forming metal-P complexes. Higher amounts of metal-P were formed in the pea rhizosphere compared to the tomato rhizosphere and in the case of soluble P compared to the solid amendment. The increase in soil-metal contact time enhanced metal-P formation.

Conclusions

The different forms of metal-P formed for the different plants under two kinds of P amendments indicate that several mechanisms are involved in metal immobilization. Metal-P complex formation in the contaminated soil depends on the type of P amendment added, duration of soil-plant contact, type of plant species, and excretion of organic acids by the plant roots in the rhizosphere.  相似文献   
9.
Laboratory/greenhouse and field experiments were conducted to evaluate the effects of salinity levels ranging from 1 to 12 dS/m on germination rate, 8 leaf seedling dry matter, seed yield, and seed oil content of the 8 Canola (Brassica napus) cultivars: ACSN1, Falcon, Shirali, Ceres, Tower, Cobra, Global, and Oyerka. Statistical results revealed that the factors: salinity, cultivar, and their interaction had significant (P<0.01) effect on germination rate and 8 leaf seedling dry matter. Based on statistical analysis seed yield was significantly influenced by both salinity and cultivar at the 5% significance level; while the cultivar factor had a significant effect on seed oil content, salinity did not show any effect on seed oil content. Analytical results, using the well-known sigmoid or S-shape salinity response function gave reliable results for determining tolerant and sensitive cultivars to salinity. Applying an existing model on canola response to salinity levels in different growth stages, the values of C 50 and P parameters were developed for local canola cultivars. Results showed that the response of cultivars to salinity levels vary in different growth stages. While a cultivar is tolerant in a growth stage, it may be sensitive to salinity in another growth stage. Based on observed data and ANOVA analysis, we concluded that ACSN1, Shiraly, and Falcon can be ranked as salt-tolerant, and Global and Oyerka as the salt-sensitive cultivars.  相似文献   
10.

Purpose

Eucalyptus forest plantations are normally devoid of understory vegetation that is often assumed to be associated with Eucalyptus allelopathic effects. The objective of this study was to determine the influence of high soil compaction and low soil moisture content on inhibition of the germination of understory seeds in Eucalyptus forests and thus would result in the scarcity of understory vegetation.

Materials and methods

The soil water content above the depth of 1 m of six major understory vegetation types was analyzed to determine if there was a correlation between soil water content and understory vegetation. The effects of soil treatment (soil-loosening vs. no soil-loosening) and water supply amount (2500, 2000, 1500, 1000, 500, 250, or 0 ml of water per day) on the seed germination rate of Stylosanthes sp. were explored using an artificial climate chamber experiment. Influence of soil source (five Eucalyptus forest soils vs. two non-Eucalyptus forest soils) and water supply (0, 50, 150, 200, or 400 ml of water every day) on the germination rate of five types of seed were assessed using a three-factor analysis of variance (ANOVA).

Results and discussion

Soil-loosening and water supply significantly (P?<?0.05) increased seed germination rate with the contribution rates of 26.14 and 42.93 %, respectively. Analysis of variance for three-factor experiments revealed a significant (P?<?0.05) effect of water supply and vegetation seed type on the germination rate of plant seeds. No significant effect of soil type was observed on germination rate, indicating that germination rate was not affected by soils in Eucalyptus forest.

Conclusions

The conservation of soil characteristics, such as water content and compaction, during the development of a Eucalyptus forest plantation may be an effective strategy for encouraging the growth of understory vegetation. This study highlights the importance that in dry areas or areas prone to long-term drought, it would be preferable to retain native vegetation.
  相似文献   
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