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51.
Md. Aminur Rahman Muhammad Zaher Kazi Md. Azimuddin Selina Yeasmine Md. Mominuzzaman Khan Aziz Arshad 《Aquaculture Research》2013,44(7):1132-1139
The fingerling‐rearing experiment of the threatened catfish, Mystus cavasius was carried out at different stocking densities in earthen nursery ponds. Twelve‐day‐old fry were stocked at 200 000 ha?1 in treatment‐1 (T1), 250 000 ha?1 in treatment‐2 (T2) and 300 000 ha?1 in treatment‐3 (T3) respectively. The mean length and weight of fry at stocking was 1.24 ± 0.25 cm and 0.11 ± 0.04 g respectively. Fry in all the experimental ponds were supplemented with SABINCO nursery feed for the first 14 days and starter‐I feed for days 15–56. The physico‐chemical parameters and plankton population of pond water were within the suitable level for fish culture. Growth in terms of final weight, final length, weight gain, length gain and specific growth rate and survival of fingerlings were significantly higher in T1 than those in T2 and T3. Feed conversion rate was significantly lower in T1 followed by T2 and T3 in that order. Significantly higher number of fingerlings was produced in T3 than that in T2 and T1. Even then, consistently higher net benefits were obtained from T1 than those from T3 and T2. Among the treatments evaluated, 200 000 fry ha?1 was the best stocking density considering the highest growth, production and net benefits of fingerlings of M. cavasius in nursery ponds. 相似文献
52.
PET fabric is coated with conducting polypyrrole (PPy) by oxidative polymerization from an aqueous solution of Py using ferric
chloride hexahydrate (FeCl3) as oxidant and p-toluene sulphonate (pTSA) as dopant. The optimum concentrations for Py, FeCl3 and pTSA were found to be 0.11, 0.857 and 0.077 mol/l respectively, which yielded a conductive fabrics with resistivity as
low as 72 Ω/sq. PPy fabric gained resistivity less than one order of magnitude when aged for 18 months at room temperature.
The stabilizing effect of the dopant pTSA against thermal degradation was demonstrated; the undoped samples reached resistivity
of around 40 kΩ, whereas doped samples reached less than 2 kΩ at the same temperature and time. 相似文献
53.
The mechanism of inhibition of alpha-chymotrypsin by benzoylsalireposide (1), a phenolic glycoside isolated from Symplocos racemosa, was investigated. Lineweaver-Burk and Dixon plots and their secondary replots showed that 1 was a non-competitive inhibitor of this enzyme with the Ki value of 29.60 microM. 相似文献
54.
Rice–Wheat rotation system utilizes surface, ground and rain water resources conjunctively. Recent studies have shown increasing
contribution of groundwater for crop irrigation. As the system utilizes water pumped from the underlying aquifer and partly
seeps back, a cycle of recharge and discharge continues. Sustainability of groundwater system for the on-going drought in
the country depends mainly on the recharge of the aquifer. The reported study was, therefore, carried out to measure and assess
the recharge contribution of a distributary of canal in Punjab, Pakistan. Assessment of recharge through distributary was
carried out using a groundwater flow “MODFLOW” model, which utilized the observed watertable, climatic, crop and soil for
a period of about 1 year in addition to hydraulic conductivity, evapotranspiration and aquifer characteristics data. The requisite
primary data for “MODFLOW” were collected from field and secondary data from public sector organizations dealing with water.
Model calibration involved changing input parameters within reasonable limits until acceptable matches were obtained between
the observed and simulated water levels for all observed hydrographs. The external inputs such as, recharge through irrigation,
precipitation, stresses due to evaporation, lateral flow and stream were simulated to calculate the monthly water budget of
aquifer. As concluded, recharge contribution was 16.5% of the inflow rate of the distributary. Using predicted results of
the model a relationship between recharge (R) and discharge (Q) was also developed. Although, the presented results of recharge
contribution were limited to one distributary of canal irrigation system, yet the developed methodology can be extended to
the other canal systems of the Indus Basin. 相似文献
55.
Syed Adeel Zafar Amjad Hameed Muhammad Amjad Nawaz Wei MA Mehmood Ali Noor Muzammil Hussain 《农业科学学报》2018,17(4):726-738
Rice, a staple cereal crop in many parts of the world, has been confronted with multiple environmental stresses including high temperature, negatively impacts the booting as well as anthesis growth stages. The situation is further complicated by the changing climatic conditions, resulting in gradual escalation of temperature as well as changing the rainfall pattern and frequency, thus raising a concern of food security worldwide. The situation can be combat by developing rice varieties with excellent genetics with improved morpho-physiological, biochemical, and molecular mechanisms, together can minimize the adverse effects of heat stress. Here, several strategies (encompassing genetic and genomic, and mechanisms involved) for mitigating the impact of high temperature on rice have been discussed. Finally, the utilization of genomic knowledge in augmenting the conventional breeding approaches have been comprehensively elaborated to develop heat tolerant germplasm. 相似文献
56.
Muhammad Usman Mehmood Ahmad Qamar Abdul Sattar Liaquat Ahmad Nasim Ahmad 《Tropical animal health and production》2017,49(2):347-351
The present study was designed to determine the effect of estradiol benzoate (EB) on reproductive response following a controlled internal drug release (CIDR) protocol in crossbred (Sahiwal × Friesian) dairy heifers. In the first trial, a total of 100 crossbred dairy heifers were treated with CIDR protocol for 7 days and injected with the PGF2α on day 6. After 24 h of CIDR removal, one group (EB?=?50) was injected with estradiol benzoate whereas the other (control?=?50) remained untreated. Estrus intensity and response were recorded visually and ovulation rate was recorded by ultrasonography. All heifers were artificially inseminated at 48 and 60 h following CIDR removal. Heifers were scanned for pregnancy within days 30–40 of artificial insemination (AI). In the second trial, two subgroups of heifers were included to observe the estrus and ovulatory events. The results of the first trial revealed that estrus response was achieved 100% in both the treatment groups. Estrus intensity (2.9?±?0.1 vs. 2.0?±?0.7) and ovulation rate (100 vs. 88%) differed significantly (P?<?0.05) between the EB and control groups. However, a tendency for higher pregnancy per AI was observed (54 vs. 36%; P?=?0.07) in EB than that in control groups. The results of the second trial revealed that a significantly (P?<?0.05) shorter estrus and earlier ovulatory events were observed in EB-treated heifers. It is concluded that the incorporation of estradiol benzoate to the CIDR protocol is helpful to improve the estrus signs and enhance the ovulation and the pregnancy per AI in crossbred dairy heifers. 相似文献
57.
Noshin Ilyas Fakhra Ambreen Nazima Batool Muhammad Arshad Roomina Mazhar Fatima Bibi 《Communications in Soil Science and Plant Analysis》2018,49(2):148-158
Crop rotation is a supportive management practice in which legumes greatly improve the growth and yield of subsequent cereal crops, particularly wheat. In this study, effects of mung bean (Vigna radiata)?? on the yield and quality of grains of following wheat crop were determined. An experiment was carried out with two sets of wheat (Triticum aestivum) crops: one grown following mung bean (Vigna radiata) crop and the other grown after a fallow period. Concentrations of macronutrients, sugar, protein, amino acids, and phytohormones of wheat were determined. The grain protein concentration of wheat was improved if cultivated after mung bean, and nitrogen and other macronutrients of wheat were increased significantly. In case of phytohormone contents in the wheat crop, abscisic acid concentration showed no change, but the concentrations of gibberellin increased significantly by 41% and indole acetic acid by 30% as a result of crop rotation. Sugar content in wheat cultivated after mung bean BRM-318 showed 10% increase and wheat protein content increased by 17% and 20%, respectively. The present study demonstrated that crop rotation simulated yield and improved the nutritional value of wheat grain compared to wheat which followed the fallow period. 相似文献
58.
We report for the first time the capability of four-leaf clover (Marsilea quadrifolia), a wetland plant which grows rooted in soil, in efficiently treating sewage. The use of M. quadrifolia was made possible because of the special attributes of the SHEFROL® (SHEet Flow ROot Level) bioreactor in which it was employed. This bioreactor enables the use of free-floating aquatic plants as well as terrestrial and rooted-in-soil wetland plants by hydroponics. The plants are staked in narrow channels to enable them to support each other while sewage is made to flow rapidly as a sheet of wastewater at a level that covers only the plant roots (hence the name). It was seen that M. quadrifolia was able to treat sewage of strength varying in the chemical oxygen demand (COD) range of 600–1800 mg/L to the extent of >?80% at a hydraulic retention time (HRT) of just 4.5 h. There was a near total removal of biological oxygen demand and suspended solids while total Kjeldahl nitrogen, soluble phosphorous, and heavy metal zinc were also substantially removed. The macrophyte was equally effective when used indoors under artificial lighting, as well as when used outdoors. 相似文献
59.
Biosolubilization of phosphorus from rock phosphate and other P fertilizers in response to phosphate solubilizing bacteria and poultry manure in a silt loam calcareous soil
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‘Phosphate solubilizing bacteria' (PSBs) are able to release unavailable P from native and applied P sources into plant‐available soil pool through their solubilizing and acidifying effects. The effects of three indigenous and one exotic PSBs on P solubilization from different P sources, plant biomass production, and P‐uptake efficiency of maize (Zea mays L.) were examined in an incubation and greenhouse study. For incubation study, surface (0–15 cm) soil was collected from an arable field (Inceptisols) and amended with rock phosphate (RP), single superphosphate (SSP), poultry manure (PM), and RP+PM with and without PSBs. The amended soil was incubated in the control environment at 25 ± 2°C for a total of a 100‐d period to establish relative potential rate of P solubilization of added P sources. A complementary greenhouse experiment was conducted in pots by growing maize as a test crop. Growth characteristics, P‐uptake, and P‐utilization efficiency (PUE) were determined. Phosphate solubilizing bacteria generated a solubilization effect on different P sources by releasing more P into plant‐available soil pool, i.e., 14.0–18.3 µg g?1 in RP, 5.0–9.9 µg g?1 in SSP, 1.4–4.4 µg g?1 in PM, and 4.5–7.8 µg g?1 in RP+PM compared to their sole application without PSBs. The available P from inorganic SSP declined continuously from the mineral pool (after day 30) and at the end 40% of applied P was unaccounted for. However, P losses were reduced to 28 and 27% when PSBs (PSB1 and PSB3) were applied with superphosphate treatments. In the absence of PSBs, the recoveries of applied P (in soil) from RP, SSP, PM and RP+PM were 4, 25, 9, and 12%, respectively, those had been increased to 14, 30, 12 and 15% in the presence of PSBs. Similarly, the plant biomass in RP+PSBs treatments compared to the RP without PSBs increased between 12–30% in first sampling (30 DAG) and 13–30% in the second sampling (60 DAG). The P utilization efficiency (PUE) in plants supplemented with PSBs was 20–73% higher compared to those without PSBs. The detection of oxalic and gluconic acids in culture medium treated with PSBs (7.8–25.0 and 25–90 mg L?1, respectively) confirmed the production of organic acids by the indigenous bacterial isolates. This study indicate that low P recovery both in plant and soil can likely be improved by using indigenous PSBs and organic amendment poultry manure, which allowed a more efficient capture of P released due to P solubilization. 相似文献
60.
Among various abiotic stresses, global drought reduces global growth and yield of wheat. Present research has been designed to ameliorate the adverse effects of drought stress on wheat by combined application of plant growth-promoting rhizobacteria (PGPR), compost, and mineral fertilizers. In this experiment, the role of fertilizer, compost, and PGPR inoculation to ameliorate drought stress was studied in two wheat varieties at vegetative stage. Water stress adversely affects morphology, physiology, and biochemistry of the wheat plant. Inoculated seed with compost and mineral fertilizer grown in drought condition showed 43% increase in relative water content (RWC) of 9.39% in Membrane Stability Index and 82.20% in chlorophyll as compared to control. Drought affected the accumulation of osmolytes, but PGPR in combination with compost and mineral fertilizer under drought stress triggered higher accumulation of soluble sugar and proline content, i.e., 28.96% and 73.91%, respectively. It is concluded from this research that PGPR in combination with compost and mineral fertilizer considerably reduces the effect of drought on wheat by enhancing the physiological (RWC, membrane stability, chlorophyll content, and water potential) and biochemical (proline and sugar) aspects of the plant. 相似文献