The effects of selenium (Se) cadmium (Cd) interactions on plant growth and metabolism are not fully clear. In the present study, we assessed whether Se could alleviate the toxic effects of Cd on growth and metabolism of maize. Seeds of maize variety FH-985 were sown in pots filled with sand treated with CdCl2 (0, 50 and 100 µM) and Se (0, 2 and 4 mg L?1) through Hoagland’s nutrient solution. Low Se (2 mg L?1) increased germination percentage and rate, while high Se (4 mg L?1) increased fresh and dry biomass under Cd stress. Interestingly, all Se concentrations were effective in alleviating the toxic effects of Cd on photosynthetic pigments, whereas higher Se mitigated the Cd-induced oxidative stress and increased flavonoids both in the shoots and roots while phenolics in the roots. The results demonstrated that root zone Se altered tissue-specific primary metabolism in maize. Furthermore, low Se mitigated the Cd-induced decrease in total proteins in the root. Overall, Se-mediated decrease in the oxidative stress in the shoots while increase of secondary metabolites in the roots helped the plants to grow faster at early growth stage and caused increase in the biomass under different Cd regimes. 相似文献
The present research aimed to assess the influence of two phosphorous (P) amendments on metal speciation in rhizosphere soil and the soil–plant transfer of metals.
Materials and methods
Complementary experiments were performed: field experiments on a contaminated cultivated soil and laboratory experiments on an uncultivated contaminated soil to highlight the mechanisms involved in metal-phosphorous interactions. In laboratory experiment, P amendments were added at 120 mg P/kg of soluble KH2PO4 amendment and 9,000 mg P/kg of solid Ca5(PO4)3OH amendment.
Results and discussion
Field-culture results showed the possible food-chain contamination due to Pb, Cd, Cu, and Zn phytoaccumulation by pea and mustard plants from a cultivated agricultural soil. Moreover, P-metal complexes were observed by microscopy in the rhizosphere soil. In laboratory experiments, the application of P amendments significantly increased Pb and Zn level in rhizosphere soil compared to control. Phosphate amendments significantly increased metal-P fraction and decreased “oxides” and “organic matter” fractions of Pb and Zn. Soluble-P amendment was more effective than solid P amendment in changing Pb and Zn speciation. The changes in metal speciation are higher in the rhizosphere soil of pea than tomato. Application of P amendments increased Pb and Zn TF root/soil but decreased TF shoot/root.
Conclusions
The effectiveness of in situ metal immobilization technique varies with the type and quantity of applied P amendment as well as plant and metal type. 相似文献
Immobilized microbial cells for the biological treatment have the potential to degrade toxic chemicals faster than conventional wastewater treatment systems. In the present study, suitability of immobilized Pseudomonas fluorescens SM1 strain in calcium alginate beads for remediation of the major toxicants in Indian water bodies was tested by means of GC/HPLC and AAS techniques. Roughly 80% reduction in the concentration of phenols was observed by immobilized SM1 cells compared with 60% by the free cells. Also, in the case of the bioremediation of heavy metals, immobilized SM1 cells were found to be more efficient compared with the free cells. Suspension of P. fluorescens SM1 cells in the test model water for 24 h brought down the concentrations of Cu++, Cd++, Ni++, and Pb++ by more than 75% under free cell state and 7?C9% better efficiency under the immobilized conditions. However, Cr(VI) could show only 44% removal by the cell immobilized system, whereas a mere 35% reduction in the Cr(VI) levels was shown in the test model water by the free SM1 cells under the same conditions. Moreover, a model water containing 2,000 ppb of BHC, 1,248 ppb mancozeb, and 312 ppb 2,4-D passed through the cell immobilized column resulted in the decline in their concentrations up to 362 ppb, 750 ppb, and 126 ppb, respectively. Generally, AAS, HPLC, and GC analyses of treated test model waters with the free and immobilized SM1 cells exhibited high potential of immobilized SM1 in detoxification of test water. From the results, we conclude that immobilized cells of P. fluorescens SM1 strain were quite effective in bioremediation of major toxicants present in Indian water bodies, and we also recommend the use of immobilized bacterial cells rather than the free cells for the bioremediation/detoxification process. 相似文献
Developing new tools for using low-quality irrigation waters is vital for the sustainability of irrigated agriculture and minimizing salt accumulation. Therefore, the present study focused on the interactive influence of irrigation treatments (magnetized (MT) and non-magnetized (NMT)) and water salinities (0.38, 1.5, 4.5, and 7.0?dSm?1) on soil salinity, water use efficiency, yield and morpho-physiological changes of Balk?z bean. A pot experiment was conducted in a randomized complete block design with three replications under the rain shelter condition. Irrigation water MT treatment increased fresh bean yield, water use efficiency (WUE) and irrigation water use efficiency (IWUE) by 21.35, 23.00 and 14.8%, respectively, while saturated soil salinity was reduced by 20%, compared to NMT treatments. The leaf area, stomata, and leaf succulence in green beans in the MT treatment significantly increased by 13.4, 23.9, and 3.3% compared with those in the NMT treatment. Stems of the bean crops were more sensitive to salinity stress followed by roots and leaves. The study revealed that irrigation with magnetically treated water manages salinity related yield loss through increased morphological features as well as osmotic and stomatal adjustments. In addition, the bean crops showed an ability to protect water in tissue against salinity toxicity up to 5.24?dSm?1 soil salinity level under magnetized saline water conditions. Finally, irrigation with magnetically treated 0.38?dSm?1 irrigation water can be recommended due to providing a higher yield, WUE, IWUE, and sustainable production under saline irrigation in water scarcity regions.
NERICA rice was developed through the hybridization of Oryza Glaberrima and Oryza sativa in an attempt to produce a higher yield in areas with a limited water supply. This study investigated the interactive effects of irrigation water salinities (0.38, 1.5, 3.0, 5.0, 7.0, 10.0 and 15?dSm?1) for various water depths (5, 10 and 15?cm) on crop yield and related components of NERICA rice variety. This study showed that increased levels of irrigation water salinity resulted in reduced rice yield, biomass weight, plant height, harvest index, 1000 grain weight, evapotranspiration, water use efficiency, stomatal conductance, and chlorophyll content, and increased plant sterility for all irrigation water depths. The threshold values of soil salinity for the NERICA rice for the 5, 10, and 15?cm depths were 2.14, 81 2.80, and 1.98 dSm?1, respectively. The study showed that the optimum salinity/water depth condition for the production of transplanted NERICA rice is irrigation water salinity <?1.50 dSm?1, and a 10?cm water depth. This irrigation water salinity level maintains the soil ECe at or below the salinity threshold value of 2.80 dSm?1. This study showed that NERICA rice has a salinity threshold value of 2.80 dSm?1. Since rice is generally considered to be more salt-sensitive during germination, it is recommended that farmers apply the least saline water available during the rice germination stage of growth. Information from this study will assist policymakers and farmers to better manage NERICA production in Sub-Saharan Africa.
Wheat (Triticum aestivum L.) is a staple food in many countries and is regarded as a vital source of nutrition. Drought is one the most prevalent limitations to wheat growth and development. Herein a two year study was conducted using 25 diverse wheat genotypes obtained from the gene pool of various research institutes of Pakistan to characterize their drought tolerance using various physiological indices like relative water content (RWC), relative dry weight (RDW), water saturation deficit (WSD), relative water loss (RWL), flag leaf area (LA), chlorophyll content index (CC) and their association with the grain yield (GY). Analysis of variance (ANOVA) indicated the presence of significant amount of differences and genetic diversity among genotypes under study. Correlation analysis exposed positive association of CC and LA with GY. However, RWC was shown to have a highly significant and negative association with WSD and RWL. Principal component analysis (PCA) showed that out of the 7 PCs only 2 were significant having eigenvalues >?1; cumulatively accounting for 88.70% and 73.03% of the total variation under control and drought stress conditions, respectively. Strikingly the results of the PCA biplots and cluster heat map exposed G1 (Barani-17), G2 (Dharabi-11), G3 (Ehsan-16), G4 (Chakwal-50), G17 (Ujala-2016) and G23 (Kohistan-97) as potential drought tolerant genotypes. Selection of the positively associated indices would be fruitful and the tolerant genotypes having drought tolerance potential could be utilized in future wheat breeding programs to develop high yielding and drought tolerant genotypes.
Journal of Plant Diseases and Protection - The fall armyworm (FAW), an invasive pest of maize, is an emerging threat in Southern Asia after America and Europe. Recently, this notorious pest has... 相似文献
Poor seed yield of soybean in Mediterranean-type environments may result from insufficient iron (Fe) uptake and poor biological nitrogen (N) fixation due to high bicarbonate and pH in soils. This study was conducted to evaluate the effects of N and Fe fertilization on growth and yield of double cropped soybean (cv. SA 88, MG III) in a Mediterranean-type environment in Turkey during 2003 and 2004. The soil of the experimental plots was a Vertisol with 176 g CaCO3 kg−1 and pH 7.7 and 17 g organic matter kg−1 soil. Soybean seeds were inoculated prior to planting with commercial peat inoculants. N fertilizer rates were 0, 40, 80, and 120 kg N ha−1 of which half was applied before planting and the other half at full blooming stage (R2). Fe fertilizer rates were 0, 200 and 400 g Fe EDTA (5.5% Fe and 2% EDTA) ha−1. It was sprayed as two equal portions at two trifoliate (V2) and at five trifoliate stages (V5). Plants were sampled at flower initiation (R1), at full pod (R4) and at full seed (R6) stages. Application of starter N increased biomass and leaf area index at R1 stage whereas Fe fertilization did not affect early growth parameters. N application continued to have a positive effect on growth parameters at later stages and on seed yield. Fe fertilization increased growth parameters at R4 and R6 stages, and final seed yield in both years. This study demonstrated an interactive effect of N and Fe fertilization on growth and yield of soybean in the soil having high bicarbonate and pH. There was a positive interaction between N and Fe at the N rates up to 80 kg N ha−1. However, further increase in N rate produced a negative interaction. Fertilization of soybean with 80 kg N ha−1 and 400 g Fe ha−1 resulted in the highest seed yield in both years. We concluded that application of starter and top dressed N in combination with two split FeEDTA fertilization can be beneficial to improve early growth and final yield of inoculated soybean in Mediterranean-type soils. 相似文献
Effects of L-carnitine administration via drinking water on growth performance, carcass traits, blood serum parameters and abdominal fatty acid composition of ducks was examined. One hundred day-old Turkish native duck chicks were divided into two groups, each with five replicates and given the same diets with 0 and 200 mg/l carnitine chlorhydrate via drinking water. The study lasted 8 weeks, with the first 4 weeks as a starter and the last 4 weeks as grower period. At the end of the study five ducks were randomly selected from each subgroup for slaughter. Growth performance parameters of ducks were not affected significantly by L-carnitine administration. Live weight, daily weight gain, cumulative feed consumption and average feed conversion efficiency were found to be 1490 and 1621 g, 26.0 and 28.1 g, 5386 and 5662 g, 3.75 and 3.54 kg/kg in the control and in the carnitine groups respectively. L-carnitine administration did not effect carcass traits and serum cholesterol, total lipid, triglyceride and glucose levels. Total saturated fatty acid content of abdominal fat significantly decreased, mono- and polyunsaturated fatty acid content were not affected by L-carnitine administration. In conclusion, L-carnitine administration by drinking water did not affect growth performance, carcass traits and blood parameters in ducks. 相似文献
Ornithogalum ulophyllum Hand.-Mazz. with beautiful white flowers is an important medicinal and ornamental plant of the Middle Eastern countries and need exploitation for commercial propagation. The study reports in vitro mass proliferation of bulblets achieved from twin scales and “in vitro regenerated bulblet” explants on MS medium supplemented with various concentrations of BAP–NAA. The best regeneration on twin scales and “in vitro regenerated bulblets” was obtained on MS medium containing 2 mg l−1 BAP–0.5 mg l−1 NAA and 2 mg l−1BAP–1 mg l−1 NAA, respectively. However, bulb scales seemed to be more potent for bulblet regeneration. A large number of the developing bulblets rooted on the regeneration medium. Remaining non-rooting bulblets were rooted on MS medium containing 1 mg l−1 NAA. All plants were acclimatized in the environmental chamber for 4 weeks and were transferred to the greenhouse for flowering. Regenerated bulblets developed into morphologically normal plants. 相似文献
