Effect of Cd on growth, physiological response, Cd subcellular distribution and chemical forms of Koelreuteria paniculata.[Pubmed: 29783107]

None

[Effects of Different Modifier Concentrations on Lead-Zinc Tolerance, Subcellular Distribution and Chemical Forms for Four Kinds of Woody Plants].[Pubmed: 26841622]

Four kinds of lead-zinc tolerant woody plants: Nerium oleander, Koelreuteria paniculata, Paulownia and Boehmeria were used as materials to estimate their enrichment and transferable capacity of lead (Pb) and zinc (Zn) and analyze the subcellular distribution and chemical speciation of Zn and Ph in different parts of plants, under different modifier concentrations (CK group: 100% lead-zinc slag plus a small amount of phosphate fertilizer, improved one: 85% of lead-zinc slag ± 10% peat ± 5% bacterial manure plus a small amount of phosphate fertilizer, improved two: 75% lead-zinc slag ± 20% peat ± 5% bacterial manure ± a small amount of phosphate). Results showed that: (1) The content of Pb, Zn in matrix after planting four kinds of plants was lower than before, no significant difference between improved one and improved two of Nerium oleander and Boehmeria was found, but improved two was better than improved one of Paulownia, while improved one was better than improved two of Koelreuteria paniculata; Four plants had relatively low aboveground enrichment coefficient of Pb and Zn, but had a high transfer coefficient, showed that the appropriate modifier concentration was able to improve the Pb and Zn enrichment and transfer ability of plants. (2) In subcellular distribution, most of Pb and Zn were distributed in plant cell wall components and soluble components while the distribution in cell organelles such as mitochondria, chloroplasts and nucleus component were less. Compared with CK group, two improved group made soluble components of the cell walls of Pb fixation and retention of zinc role in the enhancement. (3) As for the chemical forms of Pb and Zn in plants, the main chemical forms of Pb were hydrochloric acid, sodium chloride and ethanol extractable forms, while other chemical form contents were few, the main chemical forms of Zn were different based on plant type. Compared with CK group, the proportion of the active Pb chemical form in different plant parts decreased in two improved groups, while the proportion of strong activity chemical forms increased; two improved groups led strong activity Zn chemical form of root increased, while strong activity Zn chemical form of aboveground decreased.

[Impact of canopy structural characteristics on inner air temperature and relative humidity of Koelreuteria paniculata community in summer].[Pubmed: 26572013]

To investigate the diurnal variation of the correlations between the cooling and humidifying effects and canopy structural characteristics of the Koelreuteria paniculata community, the measurements of air temperature, relative humidity, canopy density, leaf area index (LAI) and mean leaf angle (MLA) were performed on calm sunny summer days in the community in Beijing Olympic Forest Park, China. There were significant correlations between the canopy density, LAI and MLA, which affected the cooling and humidifying effects together. The cooling effect reached its maximum by 12:00, whereas the humidifying effect reached its peak at 10:00. Compared with the control open space site, the community appeared to lower the air temperature by 0.43 to 7.53 °C and to increase the relative humidity by 1%-22% during the daytime. However, the cooling and humidifying effects seem to be not effective during the night. The canopy density and LAI were better for determining the cooling and humidifying effects from 9:00 to 12:00. However, these effects were largely controlled only by the canopy density from 12:00 to 14:00 and were significantly correlated with the canopy density and LAI afterwards until 18:00.

Assessing the Capacity of Plant Species to Accumulate Particulate Matter in Beijing, China.[Pubmed: 26506104]

Air pollution causes serious problems in spring in northern China; therefore, studying the ability of different plants to accumulate particulate matter (PM) at the beginning of the growing season may benefit urban planners in their attempts to control air pollution. This study evaluated deposits of PM on the leaves and in the wax layer of 35 species (11 shrubs, 24 trees) in Beijing, China. Differences in the accumulation of PM were observed between species. Cephalotaxus sinensis, Euonymus japonicus, Broussonetia papyriferar, Koelreuteria paniculata and Quercus variabilis were all efficient in capturing small particles. The plants exhibiting high amounts of total PM accumulation (on leaf surfaces and/or in the wax layer), also showed comparatively high levels of PM accumulation across all particle sizes. A comparison of shrubs and trees did not reveal obvious differences in their ability to accumulate particles based on growth form; a combination of plantings with different growth forms can efficiently reduce airborne PM concentrations near the ground. To test the relationships between leaf traits and PM accumulation, leaf samples of selected species were observed using a scanning electron microscope. Growth forms with greater amounts of pubescence and increased roughness supported PM accumulation; the adaxial leaf surfaces collected more particles than the abaxial surfaces. The results of this study may inform the selection of species for urban green areas where the goal is to capture air pollutants and mitigate the adverse effects of air pollution on human health.

[Atmospheric Particle Retaining Function of Common Deciduous Tree Species Leaves in Beijing].[Pubmed: 26387301]

In order to explore the atmospheric particle-retaining function of common deciduous tree species leaves in Beijing, six typical tree species (Populus, Robinia pseudoacacia, Koelreuteria paniculata, Salix babylonica, Acer truncatum, Ginkgo biloba) were chosen to measure retaining amount of unit leaf area of air total suspended particles (TSP), coarse particles and fine particulate with aerosol generator (QRJZFSQ-I). The results showed that (1) All six tree species leaves had a certain level of retaining ability to different sizes of atmospheric particles, and different species exhibited some differences. For different sizes of atmospheric particle, retaining amounts of unit leaf area were higher in Koelreuteria paniculata and Robinia pseudoacacia than those of other four species, and the amount of Populus was the lowest among all tree species; (2) The retaining amount of unit leaf area for different tree species was not entirely increased with sampling time. The retaining amounts of TSP and coarse particles for all tree species on the eighth day after rain were significantly higher than those on the fifth day after rain, however, the retaining amount of fine particles was not significantly different under different sampling times. In order to select deciduous tree species for ecological management of air pollution in Beijing, Koelreuteria paniculata should be considered as the priority, followed by Robinia pseudoacacia, compared with Ginkgo biloba, Salix babylonica, Acer truncatum and Populus.

Phytochemical screening and antimicrobial activities of the constituents isolated from Koelreuteria paniculata leaves.[Pubmed: 25813082]

Methanolic extract of Golden rain leaves was fractionated by column chromatography on silica gel and 18 fractions were obtained. Antimicrobial activities of fractions were investigated against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa as quality control bacteria and fungus Pyricularia grisea which causes Blast disease in rice. Fractions showed more antibacterial activity at 0.04 g/mL concentration only on B. subtilis and S. aureus as gram positive bacteria. Also, three fractions indicated excellent antifungal effect on fungus P. grisea. Moreover, in the present study, fractions that showed very good effect on microorganisms were used for gas chromatography-mass spectrometry analysis to identify different phytochemicals.

Growth and heavy metal accumulation of Koelreuteria paniculata seedlings and their potential for restoring manganese mine wastelands in Hunan, China.[Pubmed: 25654773]

The planting of trees on mine wastelands is an effective, long-term technique for phytoremediation of heavy metal-contaminated wastes. In this study, a pot experiment with seedlings of Koelreuteria paniculata under six treatments of local mine wastes was designed to determine the major constraints on tree establishment and to evaluate the feasibility of planting K. paniculata on manganese mine wastelands. Results showed that K. paniculata grew well in mine tailings, and also under a regime of equal amounts of mine tailings and soil provided in adjacent halves of pots. In contrast, mine sludge did not favor survival and growth because its clay texture limited fine root development. The bio-concentration factor and the translocation factor were mostly less than 1, indicating a low phytoextraction potential for K. paniculata. K. paniculata is suited to restore manganese mine sludge by mixing the mine sludge with local mine tailings or soil.

[Effects of exogenous Ca2+ on the seed germination of Koelreuteria paniculata in limestone area of Southwest China under drought stress].[Pubmed: 24015553]

In this paper, different arid environments in the limestone area of Southwest China were simulated by using different concentrations (0%, 5%, 15%, 25%, and 30%) of PEG6000 (polyethylene glycol), and a gradient of exogenous Ca2+ (0, 15, 20, 25, and 30 mmol x L(-1) of CaCl2) was installed to simulate the high calcium soil environments, aimed to study the effects of different concentration PEG6000, CaCl2, and their interactions on the seed germination characteristics of Koelreuteria bipinnata, one of the preferred species in the ecological restoration in limestone area. Under the action of CaCl2 alone, medium or low concentration exogenous Ca2+ had lesser effect on the seed germination parameters, but high concentration exogenous Ca2+ had inhibition effect on the seed germination. Medium or low concentration CaC12 could increase the seedling fresh biomass. When the PEG6000 concentration increased from 0% to 25%, the seed germination rate, germination potential, germination index, and vigor index showed a significant decreasing trend, and the seedling fresh biomass decreased remarkably. When certain concentration of exogenous Ca2+ was exerted to the drought treatment groups, medium or low concentration CaCl2 improved the seed germination characteristics, which compensated the loss from drought stress to a certain degree. When the CaCl2 concentration was up to 30 mmol x L(-1), the seeds were hard to germinate. Additionally, no seeds germinated under the condition of PEG with the concentration of 30%. It was suggested that applying definite concentration of exogenous Ca2+ could increase the seedling fresh biomass under PEG6000 stress, and make the seedlings more adapt to arid environment.