Advanced Materials Research Vols. 726-731

Abstract: In order to reveal the regulating capacity of mushroom residue on washed soil, pots experiments were carried out. The growth of tomatoes planted on washed soil amended by mushroom residue were measured. Mushroom residue can be helpful to improve the plant height, stem diameter, the aerial parts fresh weight, root fresh weight, leaf photosynthetic rates and photosynthesis, and lay a good foundation for the growth of tomatoes. The effect of mushroom residue is the most significant. Among all the treatments of adding 2.5%, 5%, 10% mushroom residue, adding 10% mushroom residue is the best. It can significantly enhance the growth and photosynthesis of tomatoes, and is among the best of these three soil treatments for washed soil.

Abstract: The experiment studied the 96h acute toxicity effects on three kinds of microalgae caused by Water-Accommodated Fraction (WAF), and effects of different concentrations WAF (Platymonas helgolandica var. tsingtaoensis, Nitzschia closterium f. minutissima 00.524816 mg/L; Isochrysis galbana 00.52.551020 mg/L) on chlorophyll-a content and chlorophyll fluorescence parameters. It showed that the WAF 96h EC₅₀ of the Platymonas helgolandica var. tsingtaoensis, Nitzschia closterium f. minutissima, Isochrysis galbana were 13.84mg/L, 18.83mg/L and 6.73mg/L. The level of WAF sensitivity was Nitzschia closterium f. minutissima > Platymonas helgolandica var. tsingtaoensis > Isochrysis galbana. The WAF caused inhibition of chlorophyll-a content except in condition of the low concentration. It showed the higher of the WAF concentration, the stronger the inhibition.

Abstract: Two Rumex dentatus populations, one from copper (Cu) mine and the other from uncontaminated site, were studied for plant growth, Cu accumulation and nitrogen metabolism under Cu stress. At control, nitrate content in leaves and roots of metallicolous population (MP) showed little difference from those of non-metallicolous population (NMP). At 10 μM Cu treatment, nitrate content in leaves and roots of MP were significantly higher than those of NMP. Cu treatments significantly reduced nitrate reductase activity in leaves and roots of NMP compared with the controls while not in MP. Shoot and root biomass of NMP were inhibited more significantly than those of MP. Cu concentration in shoot and root of NMP were higher than those of MP both at control and under Cu stress. These results suggested less Cu absorbed and efficient nitrogen metabolism in MP might be partly reasons why R. dentatus can colonize Cu enriched soils.

Abstract: Two Rumex dentatus populations, one from copper (Cu) mine and the other from uncontaminated site, were studied for sucrose metabolism of seed under Cu stress. Cu treatment significantly inhibited vacuolar invertase activity in non-metallicolous population (NMP), while it in metallicolous population (MP) was markedly higher than control. At control, cell wall invertase activity in MP showed little difference from NMP. However, after Cu treatment, cell wall invertase activity in MP was significantly higher than NMP. Activity of N/A-Inv was not affected by population or Cu treatment. Compared with control, sucrose and reducing sugars contents in MP were increased by Cu treatment, but those in NMP was decreased. Cu concentration in seed of NMP was higher than MP under Cu stress. These results suggested less Cu transported to seed and efficient sucrose metabolism in seed of MP might be partly reasons why R. dentatus can successful reproduction at Cu enriched soils.

Abstract: The global warming brings important effects to the ecological system, agricultural environment and crop yields. Summer maize variety ZD 958 was planted at different sowing dates and densities. Relationship between yield, ear characters and climatic factors were studied. Results showed that rainfall was the key limiting factor affecting maize production; the effective accumulated temperature after florescence was the important factor affecting bald ear tips and shrunken kernels; rainfall after florescence was the major factor affecting row grains and kernels deep; correlation between yield and average light intensity, rainfall, effective accumulated temperature reached an evident level during growth period. Rainfall had the largest direct effect on yield, and the indirect effect from effective accumulated temperature by average light intensity on yield expression was strong, while indirect effect between effective accumulated temperature and average light intensity was week. Rainfall after florescence had the maximum direct effect, while rainfall and average light intensity affecting on yield decreased significantly, direct effect effective of accumulated temperature increased obviously. 2a trials in 2011 and 2012, early sowing (April 25th) with middle density (67 500 plants·hm^-2) had the higher yield, increased 71.28% and 58.88% compared with high density (90 000 plants·hm^-2) with late sowing (May 25th) treatments. Interaction between sowing date and density had an significant effect on bald kernels and kernels deep, but little influence on row grains and barren ear tip.

Abstract: Glycine max were exposed in nine the open-top chambers to three levels of ozone (O₃) concentration (ambient, approximately 45 nL·L^-1 and two elevated ozone, 80±10 nL·L^-1 and 110±10 nL·L^-1) in four different growing stages (branching, flowering, podding and filling). In order to study the effect of different ozone concentration on photosynthesis parameters, the emphasis of this research was on photosynthetic pigment contents, parameters of photosynthetic gas exchange, Hill reaction activity and Ca²⁺/Mg²⁺-ATPase activity in soybean leaves. This paper reveals its response process and degree of photosynthesis in soybean leaves under different elevated O₃, and it could establish the foundation for the study of plants adaptability mechanism under elevated O₃ on the molecular level. The results showed that elevated O₃ concentration accelerated peroxidation damage, and plants could not tolerate O₃-induced injure, thus reducing photosynthesis by stomatal closure because of O₃ exposure in soybean leaves. And O₃ stress caused an acceleration of caducity that might be in part responsible for the reduction of photosynthesis.

Abstract: We have constructed a vector pCAMBIA1300-CP:CBF3-35S:ICE1 and transformed into Arabidopsis. Results of PCR proved that the target genes had integrated into Arabidopsis genome. Transgenic Arabidopsis showed a bit slow growth, earlier flowering, but normal at other phenotype under 22°C with 8 h daily lights. In vitro low temperature stress tests showed that the transgenic lines were survival while the wild type was nearly dead. The transgenic plants also showed an increased proline content, SOD and POD activities under low temperature stress. The phenotype and physical evidence indicated that expression of CP:CBF3-35S:ICE1 under low temperature enhances the cold tolerance in transgenic plants.

Abstract: Fluorescence spectroscopy was performed to investigate the composition changes and characteristics of the leachate DOM (dissolved organic matter) during UV-TiO₂ photocatalytic treatment process. The results showed that fulvic-like, tryptophan-like and humic acids-like matters were the main compounds in leachate. During photocatalytic treatment process, fluorescence spectroscopy of DOM changed considerably. The final products were mainly fulvic-like and tryptophan-like matters. In general, the fluorescence signals of humic acids-like matters had the most significant change, which disappeared entirely after 60 h treatment, implying that humic acids-like matters can be degraded preferentially by photocatalysis. The other notable change was in VIS fulvic-like matters region, which suggested that fulvic-like matters can be significantly degraded. In 72 h photocatalytic effluent, VIS fulvic-like, tryptophan-like and tyrosine-like matters were remained, and the last two matters were the dominant fractions. These results indicated that fulvic-like and humic acids-like matters with macromolecular can be degraded into protein-like matters with micro-molecular by photocatalysis.

Abstract: A hydroponic experiment was carried out to determine influences of partial replacement of nitrate by ammonium and 20 amino acids of alanine (Ala), valine (Val), leucine (Leu), isoleucine (Ile), proline (Pro), phenylalanine (Phe), tryptophane (Trp), methionine (Met), aspartic acid (Asp), glutamic acid (Glu), lysine (Lys), arginine (Arg), histidine (His), glycine (Gly), serine (Ser), threonine (Thr), cysteine (Cys), tyrosine (Tyr), asparagines (Asn) and glutamine (Gln) on growths and concentrations of mineral elements of pakchoi (Brassica chinensis L.). Most of amino acids inhibit shoot growths of pakchoi. Different amino acids have various effects on concentrations of calcium (Ca), manganese (Mn), magnesium (Mg), iron (Fe), copper (Cu) and zinc (Zn) in shoots of pakchoi. There are differences in shoot fresh weights, dry weights and concentrations of mineral elements of pakchoi supplied with amino acids and ammonium.

Abstract: A greenhouse pot experiment, in which 3 different crops (wheat, cabbage, spinach) were cultivated in soil with and without humics (HS), was conducted to evaluate the effect of HS on soil microbiological properties. Phospholipid fatty acid (PLFA) profiles were analyzed to reveal the microbial community structure. As a measure of the functional activity of soil microbial community, the ratio of degraded to total petroleum hydrocarbon in soil was estimated. The results indicated that HS had an important effect on the soil microbial community and its functional activities. First, the principal component analysis (PCA) of the PLFA signatures revealed marked changes between soil with HS and without HS. In addition, the total amount and the profile of PLFA were significantly different between the untreated and HS-amended soils. Using PLFA patterns as a biomarker, it was found that gram-positive bacteria (G⁺) were more sensitive to HS than gram-negative bacteria (G^-), and the biomass of G⁺ was higher in soil with HS than in that without HS. Second, the crop could stimulate the growth of soil microorganisms; however, the differences depended clearly on the crop species. The G⁺ and G^- biomass was increased in spinach soil containing HS, but was decreased in wheat and cabbage soils. The population of fungi was increased in wheat and spinach soils containing HS, but was decreased in cabbage soil. The population of actinomycetes was increased in cabbage soil, but was decreased in wheat and spinach soils containing HS. Third, the ratio of degraded to total petroleum hydrocarbon was also affected by the HS treatment. It was slightly increased in soil with HS treatment, but a significant change depended on the crop species. In general, fatty acids ranged from C13 to C19. In total, 25 different PLFAs were identified, including saturated (SAT), monounsaturated (MUFA), branched (BR), and polyunsaturated (PUFA) species. There was a clear difference in the PLFA composition between soils with and without HS.