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281.
A series of experiments was conducted with purified test diets to ascertain the optimum levels of protein and carbohydrate needed in carp feed, the details of which are indicated. Both by direct inference and by statistical analysis, it was observed that the optimum growth of carp spawn, fry and fingerlings was reached with test diets having 45% protein (casein) and 26% carbohydrate (dextrin).  相似文献   
282.
The aftermath of surface mining is a wasteland deprived of vegetation, soil structure and biodiversity. The unearthed overburden material is nutrient deprived and can only support the growth of invasive weeds such as Lantana camera which often cause allelopathy. The aim of the study is to prepare biochar from these noxious weeds and use it as an amendment for the mine spoil reclamation. Lantana biochar (LB) was prepared and applied to mine spoil, and Zea mays L. growth on biochar amended mine spoil was monitored for three months. Biochar application in a coal mine spoil using LB is comparatively de novo approach for reclamation practitioners. LB was prepared at varying temperature (250, 350 and 450℃) and residence times (30, 45 and 60 min) and characterized. After characterization, the most recalcitrant biochar at 450℃ for 60 min was chosen for application for the study. A pot trial was conducted to study the effect of LB at 0, 5, 10, 20 and 30 g kg−1 dosage on the yield of Zea mays and mine spoil properties. Significant ameliorative effects were observed with increase in organic carbon content (2.9 times), cation exchange capacity (2 times), water holding capacity (0.13 times) and decrease in bulk density (0.5 times) in the mine spoil. The seedling vigour index and germination also increased significantly (p < .05) at 30 g kg−1 biochar treatment compared to control. The study concluded that LB has the potential to remediate coal mine spoils and promote re-vegetation in degraded land.  相似文献   
283.
In recent years, a considerable number of studies have harnessed the power of genomics to decipher the role of pathogenesis‐related (PR) proteins in plant defence against various biotic and abiotic stresses. Chitinases are PR antifungal proteins expressed constitutively at low levels in plants and induced during biotic pressures and are demonstrated to be involved in the plant defence responses. Remarkable induction of chitinase enzymes by various abiotic agents (salicylic acid, jasmonic acid, ethylene and ozone) and biotic components (pathogens, insect pest, fungal cell wall components and oligosaccharides) is well demonstrated in plants. Several reviews on plant chitinase expression during host–pathogen interaction are available for annual species, whilst reports of their expression in tree species are limited to a few woody perennials: Populus, Pinus, Picea, Eucalyptus, Castanea and Pseudotsuga. The aim of this paper is to review the induction of chitinase during various stresses and developmental processes in forest tree species.  相似文献   
284.
Sida cordifolia L., Croton bonplandianum L., Malachra capitata L., Eclipta prostrata L., Clerodendron inerme L., Acalypha indica L., and Urena lobata L. are common weeds found all over India. They are often infected by different begomovirus complexes and may act as reservoirs of crop-infecting begomoviruses. Cloning and sequencing were done to partially characterize the begomovirus complexes associated with these weed species from the eastern part of India and their genetic pattern was compared with respective geographical isolates throughout India. Coat protein (CP) genes were found to be amplified from all the infected samples tested in this study, whereas betasatellite molecules amplified only from four infected samples (Sida, Croton, Malachra and Urena). Sequence analysis using CP genes and betasatellites of the present begomovirus complexes showed significant variation among their geographical isolates and also exhibited closeness to different crop-infecting begomovirus complexes. The majority of the weed-infecting begomovirus complexes characterized in this paper are reported for the first time from India.  相似文献   
285.
Aquaculture International - The main aim of the present study was to determine the effects of a seaweed-based biostimulant’s supplementation on the growth of Chlorella variabilis. A liquid...  相似文献   
286.
Production of exopolysaccharides (EPS) can be used as a criteria for the isolation of stress tolerant microorganisms. In the present study, EPS-producing fluorescent pseudomonads were isolated from alfisols, vertisols, inseptisols, oxisols, and aridisols of different semiarid millet growing regions of India and were screened in vitro for drought tolerance in trypticase soy broth supplemented with different concentrations of polyethylene glycol (PEG6000). Out of the total 81 isolates, 26 could tolerate maximum level of stress (−0.73 MPa) and were monitored for the amount of EPS produced under maximum level of water stress. The strain GAP-P45, isolated from alfisol of sunflower rhizosphere, showed the highest level of EPS production under water stress conditions, was identified as Pseudomonas putida on the basis of 16S rDNA sequence analysis, and was used as seed treatment to study its effect in alleviating drought stress effects in sunflower seedlings. Inoculation of Pseudomonas sp. strain GAP-P45 increased the survival, plant biomass, and root adhering soil/root tissue ratio of sunflower seedlings subjected to drought stress. The inoculated bacteria could efficiently colonize the root adhering soil and rhizoplane and increase the percentage of stable soil aggregates. Scanning electron microscope studies showed the formation of biofilm of inoculated bacteria on the root surface and this, along with a better soil structure, might have protected the plants from the water stress.  相似文献   
287.
The finite element model was successfully applied to predict the Pb-210 and total extractable fatty acid concentrations at different depths in two sediment cores from Lake Ontario by using different transport parameters. The transport parameters were computed from Pb-210 data. These parameters were used to simulate the total extractable fatty acid concentrations at different depths. The computed results were compared with observed data and results were compared by statistical methods. Good agreement was achieved though improved results were observed in a two layer model accounting for bioturbation in the upper 4–6 cm of sediment. By modifying this model is useful to apply the contaminant transport in lake sediments, industrial waste disposal ponds, and fish ponds with different geological, physical, chemical and biological parameters at different depths.  相似文献   
288.
The effect of I concentration on the mobility of Hg(II) in clay suspensions was studied over an environmentally-significant pH range. The addition of I decreased the adsorption of Hg(II), except at very low (50μg/L) I concentrations. In suspensions of greater I concentration (1.5 and 50 mg/L), Hg(II) adsorption was independant of pH; allow concentrations, Hg(II) adsorption decreased with increasing pH, presumably due to competition from hydroxycomplexes for surface adsorption sites. I was an effective extradant for Hg, outperforming all other halides in extraction efficiency.  相似文献   
289.
Scanning Electron Microscopy (SEM) was used to observe effects of adding increasing concentrations of neutral salts on the shapes and sizes of humic acid (HA) and fulvic acid (FA) particles. The SEM micrographs showed gradual decreases in particle orientation as well as increases in fiber thicknesses as the neutral salt concentration was increased.  相似文献   
290.
1. A study was conducted to estimate the effect of copper (Cu) supplementation on growth performance and biochemical profiles of blood and meat in broiler chickens.

2. A total of 240?d-old broiler chicks (Vencobb-100) were randomly divided into 12 groups, each of 20 chicks (4 treatments?×?3 replicates).

3. The basal diet (T1) contained 215?g?kg?1 crude protein (CP), 12·76?MJ?kg?1 ME, 32?g?kg?1 total calcium and 5?g?kg?1 total phosphorus. T2, T3 and T4 were formulated to contain an additional 75, 150 and 250?mg?Cu?kg?1 diet, respectively. Copper sulphate pentahydrate (CuSO4, 5H2O) was used as the source of Cu.

4. Significant reductions in plasma total cholesterol and triglyceride, and an elevated concentration of HDL-cholesterol, were observed in the chickens fed with 250?mg?Cu?kg?1 (T4) of feed at the 3rd and 6th week of the experiment. Total cholesterol in meat decreased significantly in the birds fed with dietary Cu at 250?mg?kg?1 (T4) of feed.

5. Growth performance was measured in terms of live weight gain, cumulative feed intake and feed conversion ratio at the end of d 21 and d 42 of the experiment, and the result was found to be commercially beneficial for the chickens receiving 150?mg?Cu?kg?1 (T3) of diet. The concentration of Cu in breast muscle and liver increased significantly at the end of experiment.

6. From this study it can be concluded that supplementation with dietary Cu may be beneficial for production performance and plasma biochemical characteristics of broiler chickens.  相似文献   

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