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Mohammad Reza Kalbassi Salar Dorafshan Tahereh Tavakolian Mahmoud Khazab & Hosein Abdolhay 《Aquaculture Research》2006,37(13):1341-1347
The karyotype and chromosomal characteristics of endangered Caspian salmon, Salmo trutta caspius, in the southern part of the Caspian Sea were investigated. From the total of 60 mitotic metaphases achieved from 15 individuals, 15, 9 and 36 metaphases were with the mode <76, 76 and 80 representing 25%, 15% and 60% of metaphases respectively. So, the most common pattern of chromosome number was 80 (36 metaphases, 60%) and the number of diploid chromosomes was thus confirmed as (2n=80) of this subspecies. The karyotype consists of seven metacentric, five submetacentric and 28 telocentric pairs. The karyological parameters of the Caspian salmon, the centromic index, arm ratio, relative length and length variation range of chromosomes, were 0–0.5, 1–∞, 0.011–0.045 and 0.507–2.028 μm respectively. The total length of chromosomes in haploid series was 44.776 μm and fundamental number of chromosome arms was 104. This study may provide the first knowledge on chromosome analysis in Caspian salmon and add basic information useful for its chromosomal manipulations. 相似文献
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Tahereh A. Aghajanzadeh Martin Reich Malcolm J. Hawkesford Meike Burow 《Archives of Agronomy and Soil Science》2019,65(7):945-956
Salinity as a major agricultural problem can affect crop growth and quality. Onion (Allium cepa L.) plant contains a wide variety of sulfur-containing compounds which may be involved in plant protection against salt stress. In the current study, a similar reduction in growth caused by chloride and sulfate salts was observed when onion was exposed to equimolar concentrations of Na+. Also, no difference was observed for shoot/root ratio and dry matter content of roots and shoots. Plants accumulated Na+ and the respective anions (chloride and sulfate) which in turn caused changes in the content of other nutrients. The content of potassium and calcium was decreased more than the other elements by both sodium salts. Sulfate salinity resulted in substantial increase in total sulfur and sulfate content but chloride salinity affected neither the total sulfur nor sulfate content of the roots and shoots, only in onion exposed to 200 mM chloride salt, those of roots and shoots were reduced. Furthermore, the water-soluble non-protein thiol content as well as the content of alliin remained rather unaffected. In conclusion, either salts affected the uptake and distribution of sulfate in onion, but had no or only a minor effect on the plant sulfur metabolism. 相似文献
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The Queensland fruit fly or ‘Q-fly,’ Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), is Australia’s most damaging insect pest of horticulture. The sterile insect technique (SIT) is being developed as a sustainable approach to management of Q-fly. New larval diets are needed for economical production of millions of artificially reared sterile flies that are required for use in SIT. Solid diets that incorporate biological bulking agents present problems of variable quality and waste disposal. Liquid diets emerged as a promising alternative, but these also suffer drawbacks, including separation of components, fermentation and need for cleaning and regular replacement of substrates that support developing larvae. The present study considers whether two promising liquid diet formulations might be improved by incorporating agar (0, 0.25, 0.5, 1.0 and 1.5%) to create semiliquid or gel diets that maintain consistent composition, suppress fermentation, negate the need for supporting substrates and minimize waste. Overall, gel diets containing greater than 0.5% agar outperformed liquid diets (0% agar) and semiliquid diets (0.25% agar) of identical nutritional composition, especially in terms of development rate and productivity. Flies from the two tested diet formulations differed in flight performance, and this likely reflects differences in concentration of wheat germ oil and/or the type of yeast used. Overall, gel diets show great promise for rearing of Q-fly, overcoming many of the constraints of both traditional solid diets and more recently developed liquid diets. There is now a need for larger-scale trials that test and refine these diets for use in operational SIT settings. 相似文献
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Sima Habibzadeh Delaram Doroud Tahereh Taheri Negar Seyed Sima Rafati 《Iranian Biomedical Journal》2021,25(5):349
Background:Flagellated protozoan of the genus Leishmania is the causative agent of vector-borne parasitic diseases of leishmaniasis. Since the production of recombinant pharmaceutical proteins requires the cultivation of host cells in a serum-free medium, the elimination of FBS can improve the possibility of large-scale culture of Leishmania parasite. In the current study, we aimed at evaluating a new serum-free medium in Leishmania parasite culture for future live Leishmania vaccine purposes. Methods:Recombinant L. tarentolae secreting PpSP15-EGFP and wild type L. major were cultured in serum-free (CSFM) and serum-supplemented medium. The growth rate, protein expression, and infectivity of cultured parasites in both conditions was then evaluated and compared. Results:Diff-Quick staining and epi-fluorescence microscopy examination displayed the typical morphology of L. major and L. tarentolae-PpSP15-EGFP promastigote grown in CSFM medium. The amount of EGFP expression was similar in CSMF medium compared to M199 supplemented with 5% FBS in flow cytometry analysis of L. tarentolae-PpSP15-EGFP parasite. Also, a similar profile of PpSP15-EGFP proteins was recognized in Western blot analysis of L. tarentolae-PpSP15-EGFP cultured in CSMF and the serum-supplemented medium. Footpad swelling and parasite load measurements showed the ability of CSFM medium to support the L. major infectivity in BALB/C mice. Conclusion:This study demonstrated that CSFM can be a promising substitute for FBS supplemented medium in parasite culture for live vaccination purposes. Key Words: Growth rate, L. major, L. tarentolae, Serum-free medium, PpSP15-EGFP protein 相似文献
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The interactions between soil P availability and mycorrhizal fungi could potentially impact the activity of soil microorganisms and enzymes involved in nutrient turnover and cycling, and subsequent plant growth. However, much remains to be known of the possible interactions among phosphorus availability and mycorrhizal fungi in the rhizosphere of berseem clover (Trifolium alexandrinum L.) grown in calcareous soils deficient in available P. The primary purpose of this study was to look at the interaction between P availability and an arbuscular mycorrhizal (AM) fungus (Glomus intraradices) on the growth of berseem clover and on soil microbial activity associated with plant growth. Berseem clover was grown in P unfertilized soil (−P) and P fertilized soil (+P), inoculated (+M) and non-inoculated (−M) with the mycorrhizal fungus for 70 days under greenhouse conditions. We found an increased biomass production of shoot and root for AM fungus-inoculated berseem relative to uninoculated berseem grown at low P levels. AM fungus inoculation led to an improvement of P and N uptake. Soil respiration (SR) responded positively to P addition, but negatively to AM fungus inoculation, suggesting that P limitation may be responsible for stimulating effects on microbial activity by P fertilization. Results showed decreases in microbial respiration and biomass C in mycorrhizal treatments, implying that reduced availability of C may account for the suppressive effects of AM fungus inoculation on microbial activity. However, both AM fungus inoculation and P fertilization affected neither substrate-induced respiration (SIR) nor microbial metabolic quotients (qCO2). So, both P and C availability may concurrently limit the microbial activity in these calcareous P-fixing soils. On the contrary, the activities of alkaline phosphatase (ALP) and acid phosphatase (ACP) enzymes responded negatively to P addition, but positively to AM fungus inoculation, indicating that AM fungus may only contribute to plant P nutrition without a significant contribution from the total microbial activity in the rhizosphere. Therefore, the contrasting effects of P and AM fungus on the soil microbial activity and biomass C and enzymes may have a positive or negative feedback to C dynamics and decomposition, and subsequently to nutrient cycling in these calcareous soils. In conclusion, soil microbial activity depended on the addition of P and/or the presence of AM fungus, which could affect either P or C availability. 相似文献
6.
Tahereh RAIESI 《干旱区科学》2015,7(5):644-652
The biological and chemical conditions of the rhizosphere are known to considerably differ from those of the bulk soil, as a consequence of a range of processes that are induced either directly by the activity of plant roots or indirectly by the stimulation of microbial population and activity in the rhizosphere. Information about phosphorus(P) fractionation in the rhizosphere soils amended with municipal sewage sludge(MSS) is limited. were We carried out greenhouse experiments using a rhizobox in order to evaluate the effects of bean rhizosphere on the various inorganic P(Pi) fractions, organic P(Po), P in particulate fraction(PF-P), Olsen-P, dissolved organic C(DOC), microbial biomass P(MBP) and alkaline phosphatase(ALP) enzyme in 10 calcareous soils amended with MSS(10 g MSS was added to 1 kg soil). Non-occluded P, occluded P, calcium phosphate and residual P were also quantitated. The results showed that DOC, MBP and ALP activity strongly increased and PF-P and Olsen-P decreased in the rhizosphere soils compared with in the bulk soils(P<0.05). The contents of non-occluded P, occluded P and residual-P fractions in the rhizosphere soils were lower than in the bulk soils, while the contents of calcium phosphate and organic P in the rhizosphere soils were higher than in the bulk soils. Simple correlation coefficients showed that P uptake had positive relationship with non-occluded P, occluded P, calcium phosphate fractions and PF-P in the rhizosphere soils. The results suggest that the short-term application of MSS to the calcareous soils may increase Po and calcium phosphate fractions in the rhizosphere soils, and calcium phosphate fraction is potentially available to crops. 相似文献
7.
Sayed Zia Mohammadi Tahereh Rohani Leila Bahadori 《Communications in Soil Science and Plant Analysis》2017,48(11):1359-1368
In the present work, magnetic iron oxide nanoparticles (MIONPs) coated with sodium dodecyl sulfate (SDS) and modified with 1-(2-pyridylazo)-2-naphthol (PAN) as a new nanoparticle were prepared and used as an adsorbent for the extraction and preconcentration of copper ions. After adsorption, copper ions were desorbed with nitric acid (HNO3), followed by determination with flame atomic absorption spectrometry (FAAS). The extraction conditions0. were investigated systematically. The linear range 3.0–500.0 ng mL?1 and the detection limit of 0.6 ng mL?1 were obtained. The relative standard deviation (RSD) of the method for seven replicate determinations of 0.1 µg mL?1 of Cu(II) was 2.2%. The method was applied for the determination of Cu(II) in different water samples with good trueness. The accuracy was also evaluated through analyses of a certified reference material (CRM TMDW-500). 相似文献
8.
Nikravesh-Masouleh Tahereh Seidavi Alireza Kawka Magdalena Dadashbeiki Mohammad 《Tropical animal health and production》2018,50(3):635-641
Tropical Animal Health and Production - The aim of this study was to evaluate the effect of different dietary energy and protein supplements on performance, weekly body sizes or body frame size,... 相似文献
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The aim of this study was to determine the effects of plant absence or presence on microbial properties and enzyme activities at different levels of salinity in a sandy clay soil. The treatments involved five salinity levels—0.5 (control), 2.5, 5, 7.5, and 10 dS m?1 which were prepared using a mixture of chloride salts—and three soil environments (unplanted soil, and soils planted with either wheat or clover) under greenhouse conditions. Each treatment was replicated three times. At the end of the experiment, soil microbial respiration, substrate-induced respiration (SIR), microbial biomass C (MBC), and enzyme activities were determined after plant harvest. Increasing salinity decreased soil microbial properties and enzyme activities, but increased the metabolic quotient (qCO2) in both unplanted and planted soils. Most microbial properties of planted soils were greater than those of unplanted soils at low to moderate salinity levels, depending upon plant species. There was a small or no difference in soil properties between the unplanted and planted treatments at the highest salinity level, indicating that the indirect effects of plant presence might be less important due to significant reduction of plant growth. The lowered microbial activity and biomass, and enzyme activities were due to the reduction of root activity and biomass in salinized soils. The lower values of qCO2 in planted than unplanted soils support the positive influence of plant root and its exudates on soil microbial activity and biomass in saline soils. Nonetheless, the role of plants in alleviating salinity influence on soil microbial activities decreases at high salinity levels and depends on plant type. In conclusion, cultivation and growing plant in abandoned saline environments with moderate salinity would improve soil microbial properties and functions by reducing salinity effect, in particular planting moderately tolerant crops. This helps to maintain or increase the fertility and quality of abandoned saline soils in arid regions. 相似文献