共查询到10条相似文献，搜索用时 46 毫秒
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Todd A. Aschenbach 《Restoration Ecology》2006,14(1):21-27
Soil salinization resulting from agricultural and oil‐ and gas‐production activities can impact habitats of native flora and fauna and reduce production on agricultural lands. Restoration of saline areas with salt‐tolerant vegetation may alleviate impacts. However, differences in how the growth rate under saline conditions varies between species and source populations must first be evaluated before recommending species for restoration. Plant material of Western wheatgrass (Pascopyrum smithii) and Inland saltgrass (Distichlis spicata) collected from Cheyenne Bottoms Preserve, Kansas and Little Salt Fork Marsh, Nebraska was propagated to evaluate variation in growth rates between these species under saline conditions and determine if differences exist between populations within these species. Ten transplants of each species from each location were grown in sand culture in a greenhouse for 51 days and watered with one of five different saltwater solutions (0.86 dS/m, 9.85 dS/m, 17.85 dS/m, 32.5 dS/m, and 57.7 dS/m). Results indicate that P. smithii grew faster than D. spicata at all comparable salinity levels. Only D. spicata exhibited significant differences in growth rate under saline conditions between populations. Results suggest that P. smithii is equivalent to D. spicata in salt tolerance and should be regarded as an appropriate halophyte for restoration of salt‐affected plant environments. Results for D. spicata suggest that differences between source populations should be considered when evaluating plant material for plant community restoration. 相似文献
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In May 2004, 400 tree seedlings of seven different species found on tree islands in the Florida Everglades were planted at different elevations along five transects on eight newly constructed tree islands, four with and four without limestone cores. Seedlings suffered between 40 and 85% mortality during the first 120 days, the period with the lowest water levels. Ilex cassine L., Salix caroliniana Michx., Chrysobalanus icaco L., and Annona glabra had the highest number of surviving seedlings, whereas Magnolia virginiana L., Myrica cerifera L., and Acer rubrum L. had the fewest. During the remainder of the study, water levels were mostly higher and sometimes covered the entire islands for months at a time. After 220 days, nearly all seedlings of M. virginiana and My. cerifera had died. At the end of the study, seedlings of I. cassine and A. glabra had the highest survivorship rates. Seedling biomass of C. icaco and I. cassine was greatest at the highest elevations, whereas seedlings of A. glabra had similar biomass at all elevations. Seedling survivorship was not statistically different between islands with and without limestone cores; however, when seedlings of all species were combined, island core type was significantly different for aboveground biomass, seedling height, and canopy width. Because of the higher survivorship under both low and high water conditions, A. glabra , I. cassine , and S. caroliniana are the most suitable species for establishing tree species on restored tree islands in the Everglades. 相似文献
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Peter A. Kulakow A. P. Schwab M. K. Banks 《International journal of phytoremediation》2000,2(4):297-317
Rapid and cost-effective techniques are needed to select plant species and genotypes for use in phytoremediation, vegetative capping, or revegetation at hazardous waste sites. A greenhouse screening procedure to aid the selection of plant materials would help increase success and decrease the cost. Twenty-nine vascular plant species were compared for growth in weathered sediments contaminated with petroleum hydrocarbons. An uncontaminated reference soil was used to estimate relative seedling growth in stressed and unstressed conditions. Plants were grown in a greenhouse and harvested at 60 and 180 days after planting to estimate variation in seedling growth and full-season growth. Plant growth characteristics measured included height, aboveground biomass, root biomass, root diameter, root-length density, and root surface area density. Concentration of total petroleum hydrocarbons (TPH) was estimated at the final harvest. Considerable variation existed among species for all characteristics except TPH concentration. Under the conditions and length of this trial, no variations in rates of TPH degradation were detected. In general, plant growth was stunted in the contaminated soil compared with the uncontaminated soil; however, differences among plant species for relative seedling growth indicated that they varied in their tolerance to the petroleum hydrocarbon-contaminated soil. For example, tall fescue, Festuca arundinacea, seemed tolerant to the contaminated soil, whereas barley, Hordeum vulgare, seemed sensitive. Comparison of results from the 60- and 180-day harvests suggested that a short-season greenhouse screening could aid selection of species for planting in contaminated soil, if plant growth results are interpreted along with information on the life history characteristics of the species under consideration. 相似文献
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Protein phosphatase 2A (PP2A) is an enzyme consisting of three subunits: a scaffolding A subunit, a regulatory B subunit and a catalytic C subunit. PP2As were shown to play diverse roles in eukaryotes. In this study, the function of the Arabidopsis PP2A‐C5 gene that encodes the catalytic subunit 5 of PP2A was studied using both loss‐of‐function and gain‐of‐function analyses. Loss‐of‐function mutant pp2a‐c5‐1 displayed more impaired growth during root and shoot development, whereas overexpression of PP2A‐C5 conferred better root and shoot growth under different salt treatments, indicating that PP2A‐C5 plays an important role in plant growth under salt conditions. Double knockout mutants of pp2a‐c5‐1 and salt overly sensitive (sos) mutants sos1‐1, sos2‐2 or sos3‐1 showed additive sensitivity to NaCl, indicating that PP2A‐C5 functions in a pathway different from the SOS signalling pathway. Using yeast two‐hybrid analysis, four vacuolar membrane chloride channel (CLC) proteins, AtCLCa, AtCLCb, AtCLCc and AtCLCg, were found to interact with PP2A‐C5. Moreover, overexpression of AtCLCc leads to increased salt tolerance and Cl? accumulation in transgenic Arabidopsis plants. These data indicate that PP2A‐C5‐mediated better growth under salt conditions might involve up‐regulation of CLC activities on vacuolar membranes and that PP2A‐C5 could be used for improving salt tolerance in crops. 相似文献
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Robin L. Brigmon Christopher J. Berry Arielle Wade Waltena Simpson 《Soil & Sediment Contamination》2016,25(3):241-255
Oil sands are a major source of oil, but their industrial processing generates tailings ponds that are an environmental hazard. The main concerns are mature fine tailings (MFT) composed of residual hydrocarbons, water, and fine clay. Tailings ponds include toxic contaminants such as heavy metals, and toxic organics including naphthenics. Naphthenic acids and polyaromatic hydrocarbons (PAHs) degrade very slowly and pose a long-term threat to surface and groundwater, as they can be transported in the MFT. Research into improved technologies that would enable densification and settling of the suspended particles is ongoing. In batch tests, BioTiger?, a microbial consortium that can metabolize PAHs, demonstrated improved oil sands tailings settling from a Canadian tailings pond. Results also showed, depending on the timing of the measurements, lower suspended solids and turbidity. Elevated total organic carbon was observed in the first 48 hours in the BioTiger?-treated columns and then decreased in overlying water. Oil sands tailings mixed with BioTiger? showed a two-fold reduction in suspended solids within 24 hours as compared to abiotic controls. The tailings treated with BioTiger? increased in microbial densities three orders of magnitude from 8.5 × 105 CFU/mL to 1.2 × 108 CFU/mL without any other carbon or energy source added, indicating metabolism of hydrocarbons and other available nutrients. Results demonstrated that bioaugmentation of BioTiger? increased separation of organic carbon from particles in oil sands and enhanced settling with tailings with improved water quality. Journal style is for Abstract to be less than 200 words, and contain no citations to other sources; please edit as needed 相似文献
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Leakage of UV-absorbing substances as a measure of salt injury in leaf tissue of woody species 总被引：2，自引：0，他引：2
Leakage of UV-absorbing substances from leaf discs was used to determine salt and osmotic injury after treatment. A relative leakage ratio was calculated by dividing the UV absorption after treatment by the total absorption obtained after freeze-killing the tissue. Time-course results using Populus tremuloides Michx. leaves indicated 24 h as an appropriate treatment duration. NaCl and KCl caused more leakage than Na2 SO4 and K2 SO4 in P. tremuloides and Fraxinus pennsylvanica Marsh, the most sensitive species tested. Amelanchier alnifolia (Nutt.) Nutt. ex Roem. was more sensitive to K2 SO4 than to KCl. Elaeagnus angustifolia L. and Caragana arborescens Lm. were the most tolerant to both salts. Tolerance to salts was greater in August than earlier in the growing season. Treatment of leaves with solutions of sucrose, PEG-8000 and mannitol iso-osmotic with KCl and NaCl showed that increased leakage was caused by specific ion effects, rather than osmotic effects. 相似文献
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比较了4个大豆品种出苗期和苗期的耐盐性,测定150 mmol/L NaCl胁迫下的株高、下胚轴长、侧根数、地上干/鲜重、根干/鲜重、MDA含量、SOD活性、游离Pro含量,并将幼苗移栽到田间生长至成熟。结果表明:出苗期和苗期盐胁迫下4个品种的株高都显著降低、地上干/鲜重和根干/鲜重降低;出苗期胁迫侧根数减少,下胚轴长降低;而苗期胁迫侧根数增加,下胚轴长升高。未胁迫条件下,出苗期和苗期耐盐性强的品种22021-1的MDA含量和SOD活性高于耐盐性弱的品种22293-1。胁迫后,22021-1的MDA含量降低、SOD活性升高,其MDA含量分别比对照低51.03%和21.45%,SOD活性比对照高5.85%和45.77%;22293-1的MDA含量出苗期比对照高58.97%,苗期基本无变化,SOD活性出苗期和苗期升高都不显著。MDA和SOD可以作为大豆耐盐性筛选指标。早期的短时胁迫对不同耐盐性大豆品种的经济产量影响不同。 相似文献