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1.
T. Aftab M. M. A. Khan M. Idrees M. Naeem M. Ram 《Journal of Agronomy and Crop Science》2010,196(6):423-430
Boron is an essential plant micronutrient and the range between deficient and toxic levels of boron is narrow for most of the plants. Like other elements, boron becomes toxic to growth at high concentrations. High boron concentrations in soil reduce crop productivity in many areas of the world. The effect of increasing levels of boron (0, 0.50, 1.00, 1.50, 2.00 mm ) on oxidative stress, antioxidant defence response and changes in artemisinin content in Artemisia annua were investigated in the present study. Boron toxicity reduced the growth parameters viz. stem height, fresh weight and dry weight. Treatments induced oxidative stress resulting in lower net photosynthetic rate, stomatal conductance, internal CO2 and total chlorophyll content. The increased activities of antioxidant enzymes like CAT, POX and SOD were also noted in response to increasing levels of boron stress. However, H2O2 and artemisinin content were found to be high up to 1.00 mm concentration of boron compared to control, and on applying higher doses, further reduced contents were obtained. Thus, the results suggest that a mild stress of boron can be utilized for enhanced artemisinin production. 相似文献
2.
Preckel T Fung-Leung WP Cai Z Vitiello A Salter-Cid L Winqvist O Wolfe TG Von Herrath M Angulo A Ghazal P Lee JD Fourie AM Wu Y Pang J Ngo K Peterson PA Früh K Yang Y 《Science (New York, N.Y.)》1999,286(5447):2162-2165
In vitro PA28 binds and activates proteasomes. It is shown here that mice with a disrupted PA28b gene lack PA28a and PA28b polypeptides, demonstrating that PA28 functions as a hetero-oligomer in vivo. Processing of antigenic epitopes derived from exogenous or endogenous antigens is altered in PA28-/- mice. Cytotoxic T lymphocyte responses are impaired, and assembly of immunoproteasomes is greatly inhibited in mice lacking PA28. These results show that PA28 is necessary for immunoproteasome assembly and is required for efficient antigen processing, thus demonstrating the importance of PA28-mediated proteasome function in immune responses. 相似文献
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M. Naeem Mohd. Idrees M. Masidur Alam Tariq Aftab M. Masroor A. Khan Moinuddin 《Russian Agricultural Sciences》2012,38(2):106-113
Recently, brassinosteroids (BRs) have emerged as a new group of growth promoting phytohormones. 28-homobrassinolide (HBR) is one of the several brassinosteroids, the role of which in enhancing growth, productivity and quality of plants, via improving various physiological processes, has been established both under stress and normal conditions. Out of a large number of essential oil bearing plants, mint (Mentha arvensis L.) constitutes the most important source of therapeutic agents used in the alternative systems of medicine. The mint plant has marvelous medicinal and aromatic values. In view of enhancing yield and quality of this medicinally important plant, a pot experiment was conducted under natural conditions of net house. The study was aimed at exploring the effect of four concentrations of HBR (10?0, 10?8, 10?7 and 10?6 M) on the performance of mint with regard to physiological attributes, herbage yield, content and yield of essential oil, and active constituents at 100 and 120 days after planting. The foliar application of HBR enhanced physiological attributes, herbage yield and the yield and content of most of the active constituents (menthol, L-methone, isomenthone and menthyl acetate) of mint at both the stages, with 10?7 M concentration proving the best. However, the next higher concentration of HBR (10?6 M) exhibited no further increase in the values of the attributes studied. Rather, 10?6 M was slightly inferior to 10?7 M concentration; but it always proved significantly better than the control. 相似文献
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Hyacinth bean (Lablab purpureus L.) serves as a good source of vegetable proteins in human diet. Its seeds and pods contain as much as 20–28% protein. Besides, it contains tyrosinase enzyme, which has potential use in the treatment of hypertension. Phosphorus deficiency causes a serious yield and quality constraint of beans at Aligarh, Western Uttar Pradesh, India. To address the problem, a pot experiment was conducted to study the effect of basal phosphorus application on the agricultural performance of this medicinal legume. The plants were grown in pots containing soil supplied with five levels of phosphorus viz. 0, 25, 50, 75 and 100 mg P kg−1 soil as potassium dihydrogen orthophosphate (KH2PO4). The growth and other physiological attributes, leaf nutrient contents, nodule-nitrogen and leghemoglobin content were studied at 60, 90 and 120 days after sowing (DAS), photosynthesis and other related parameters were measured at 90 DAS and yield and quality attributes were recorded at harvest (150 DAS). Nitrate reductase and carbonic anhydrate activities, leaf-N, -P, -K and -Ca contents and nodule-nitrogen and leghemoglobin contents reached the maximum extent at 60 DAS. At 90 and 120 DAS, the values decreased significantly. Chlorophyll content, carotenoids content, and photosynthesis were at maximum level at 90 DAS. At various growth stages, phosphorus application at 75 mg P kg−1 soil resulted in maximum amelioration of most of the parameters studied. It increased the seed-yield by 38.3%, seed-protein content by 14.9% and seed-carbohydrate content by 5.0%, relative to the control. It was concluded that there was a hidden hunger of hyacinth bean for phosphorus owing to soil-phosphorus deficiency that was ameliorated effectively by its basal dressing at 75 mg P kg−1 soil. 相似文献
5.
G.?M.?Shafiur Rahman Hrithita?Aftab M.?Shariful IslamEmail author Muhammad?Zobayer?Bin?Mukhlish Farhad?Ali 《Fibers and Polymers》2016,17(1):59-65
Bio-based CaCO3 powder was synthesized via size reduction method from waste eggshells. The XRD analysis revealed that eggshell powder consists of CaCO3 in calcite form. The inclusion level of CaCO3 contents were varied of 5, 10, 15, 20 and 25 wt.% of prepared CaCO3-polyester film. Effects of different proportions of prepared chicken eggshell and commercial CaCO3 filler on the polyester resin composites films were compared by means of mechanical and physical test. It was found that the addition of CaCO3 filler to the polyester films leads to improve the mechanical properties. The findings revealed that the best and optimum CaCO3 filler content was 10 wt.% and among the prepared polyester films, eggshell CaCO3-polyester films showed the best performance. The mechanical properties of CaCO3-polyester films were measured in terms of tensile strength, elongation-at-break, tensile modulus, flexural strength and impact strength. For eggshell CaCO3- polyester films, the maximum values of the aforementioned mechanical properties were 52.70 MPa, 4.63 %, 1868.70 MPa, 101.20 MPa and 8.40 kJ/m2, respectively, whereas for commercial CaCO3-polyester films those values were 48.12 MPa, 4.50 %, 1790.30 MPa, 97.50 MPa and 8.21 kJ/m2, respectively. Further, water absorption of the composite films as a function of time had also been investigated at 10 wt.% filler content. 相似文献
6.
Mairaj G Akhtar S Khan AR Ullah Z Bibi S Ali S 《Pakistan journal of biological sciences: PJBS》2008,11(5):797-800
The present study was designed to evaluate different honey samples obtained from local market for their quality parameters for assessment of their feasibility for foreign export by comparing it with international standards. The study was conducted at PCSIR laboratories complex, Peshawar, during 2006. The tested samples were evaluated for moisture content, Ash percentage, acid content, HMF and reducing sugars percentage. The moisture content of locally produced honey was in the range of 14.5 to 18.23%. The ash content of locally produced honey samples ranged between 0.047-0.35 which is within the standard limits. The acid content of the honey samples ranged between 19.5 and 38.0 meq kg(-1). The HMF contents of locally produced honeys ranged from 5.3 to 23.20 mg kg(-1). The content of reducing sugar of the tested samples ranged between 43.14 and 81.40% for the tested samples of locally produced honey. All of the samples were found to be in acceptable range of international standards for all of the tested parameters except for only one sample with lower reducing sugars. These samples were marked to be according to the international standards and are healthy for human consumption. 相似文献
7.
Yousef S. Al-Hafedh Aftab Alam Mohamed Salaheldin Beltagi 《Journal of the World Aquaculture Society》2008,39(4):510-520
An indoor aquaponic system (i.e., the integration of fish culture with hydroponic plant production in a recirculating setup) was operated for maximizing water reuse and year-round intensive food production (Nile tilapia, Oreochromis niloticus , and leaf lettuce) at different fish feed to plants ratios. The system consisted of a fish culture component, solid removal component, and hydroponic component comprising six long channels with floating styrofoam rafts for holding plants. Fish culture effluents flowed by gravity from the fish culture component to the solid removal component and then to the hydroponic component. Effluents were collected in a sump from which a 1-horsepower in-line pump recirculated the water back to the fish culture tanks at a rate of about 250 L/min. The hydroponic component performed as biofilter and effectively managed the water quality. Fish production was staggered to harvest one of the four fish tanks at regular intervals when fish attained a minimum weight of 250 g. Out of the total eight harvests in 13 mo, net fish production per harvest averaged 33.5 kg/m3 of water with an overall water consumption of 320 L/kg of fish produced along with the production of leaf lettuce at 42 heads/m2 of hydroponic surface area. Only 1.4% of the total system water was added daily to compensate the evaporation and transpiration losses. A ratio of 56 g fish feed/m2 of hydroponic surface effectively controlled nutrient buildup in the effluents. However, plant density could be decreased from 42 to 25–30 plants/m2 to produce a better quality lettuce. 相似文献
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In this presentation,we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term,from cultures of Tectona grandis L.Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenic shoot-culture establishment.Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N 6-benzyleadenine (BA,8.8 μmol L-1) and indole-3-butyric acid (IBA,2 μmol L-1) for 24 months.Vigorously growing shoot tips (2 3 cm long) were inoculated on the MS basal medium supplemented with different concentrations (0,1,2,4,6,8 or 10 μmol L-1) of either IBA or α-naphthaleneacetic acid (NAA) for rooting.Axillary and de novo shoots were developed from axillary and cut basal ends of shoots,respectively.Shoots growing on auxins were further sub-cultured (every 15 days) and maintained for 45 days.The greatest number of de novo (5.06) as well as axillary shoots (2.85) was observed on the MS medium supplemented with 10 μmol L-1 NAA or 8 μmol L-1 IBA,respectively,after 45 days.The combinations of both IBA (μmol L-1) + NAA (μmol L-1) were tested at different concentrations (4 + 4,6 + 6,8 + 8) supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots.Rooting from non-decapitated de novo shoots was highest (93.33%) with a mean number of roots of 4.61 on this medium,supplemented with 6 μmol L-1 IBA + 6 μmol L-1 NAA,after 36 days of initial culture.Individual auxin,however,was not effective for root induction.Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field. 相似文献
10.
Iftikhar?Ahmad Khan Faisal?Saeed AwanEmail author Aftab?Ahmad Yong-Bi?Fu Ahsan?Iqbal 《Genetic Resources and Crop Evolution》2005,52(3):239-244
Wheat breeding in Pakistan started in 1930s before partition in the United India and so far has released more than 68 cultivars, but no systematic analyses of the genetic diversity of Pakistan wheat have been made. Twenty Pakistan wheat cultivars released from 1933 to 2002 were examined for genetic diversity and relationships using random amplified polymorphic DNA (RAPD) markers. Forty-two RAPD primers were applied and 184 polymorphic bands were generated for each cultivar. Most of the cultivars were genetically interrelated, although six of them displayed some genetic distinctness. The RAPD variation observed among these cultivars was low. Only 40.7% of the total scorable bands were polymorphic, and 26.1% of the polymorphic bands were observed most frequently (f = 0.95) among the 20 cultivars. The proportions of polymorphic bands for each cultivar ranged from 0.67 in ‘Yecora’ to 0.84 in ‘C-250’ with an average of 0.76. About 1.4% of the RAPD variation might have been fixed over the 69 years of wheat breeding, but such fixation was not statistically significant. These results are significant for future improvement and conservation of Pakistan wheat. 相似文献