Showing papers in "Soil Science and Plant Nutrition in 2002"
TL;DR: In this article, suspension-cultured tobacco cells (Nicotiana tabacum L. cv. Barley 21) were treated with 0.1 (control condition), 10, and 20 mm of boron (B).
Abstract: Suspension-cultured tobacco cells (Nicotiana tabacum L. cv. Barley 21) were treated with 0.1 (control condition), 10, and 20 mm of boron (B). The histochemical observations revealed the deposition of suberin in the walls of the 10 and 20 mm B-treated cells. Lignin content and the amount of phenolics esterified to the polysaccharides of the walls of the 10 and 20 mm B-treated cells were also higher than those in the 0.1 mm of B. Lignosuberization of the 10 and 20 mm B-treated tobacco cells was accompanied by the increase in the activities of phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), peroxidase (PO), and polyphenol oxidase (PPO). In spite of the lignosuberization of tobacco cells after treatment with 10 and 20 mm of B, no significant reduction was observed in their viability, compared to those under the control conditions.
188 citations
TL;DR: The strontium isotope ratio (87Sr / 86Sr) of brown rice (Oryza sativa L.) was determined by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in order to evaluate the values of 87Sr/86Sr for use in the estimation of the area of rice production.
Abstract: The strontium isotope ratio (87Sr / 86Sr) of brown rice (Oryza sativa L.) was determined by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in order to evaluate the values of 87Sr / 86Sr for use in the estimation of the area of rice production. Sample solutions were prepared from 5 g of rice samples using the acid (HNO3-HClO4-HF) digestion method. Removal of rubidium from the sample solutions was performed using ion-exchange resin (Dowex 50W X8). The Sr isotope ratios were determined with a precision of < 0.01% (RSD, repetitions = 60) by MC-ICP-MS. Typical analysis time for a single sample was about 15 min, reflecting the high sample throughput. The Sr isotope ratios of the Japanese rice samples ranged from 0.706 to 0.709. The Sr isotope ratios of the Chinese and Vietnamese rice samples (0.710 to 0.711) were slightly higher than those of almost all the Japanese samples. Australian rice showed the highest Sr isotope ratio (0.715 to 0.717) among all the rice samples exam...
108 citations
TL;DR: In this paper, the influence of inorganic soil amendments on the effectiveness of arbuscular mycorrhizal (AM) fungi was investigated in pot experiments, and the inorganic materials improved the soil physical properties: the intact materials increased the gaseous phase of the media and the ground materials increased aqueous phase.
Abstract: The influence of inorganic soil amendments on the effectiveness of indigenous arbuscular mycorrhizal (AM) fungi was investigated in pot experiments. Intact or ground perlite, Kanumatsuchi (volcanic ash soil), vermiculite, or rice-hull charcoal was mixed with uncultivated soil in which Glomus sp. was dominant, and marigold (Tagetes patula L.) was sown to the soil mixtures. AM colonization of the host roots increased by the incorporation of ground materials but not by that of intact materials. The growth promotive effect of the indigenous fungi on the host was enhanced by both the intact and ground materials. The inorganic materials improved the soil physical properties: the intact materials increased the gaseous phase of the media and the ground materials increased the aqueous phase. It was suggested that the inorganic soil amendments might not only provide a less-competitive habitat for the fungi but also improve the physical environment.
81 citations
TL;DR: In this paper, the effect of Nand S application on the total glucosinolate (GSL) content in the edible parts of vegetable turnip rape cv. No. 21 (Brassica rapa L.) was studied.
Abstract: Effect of Nand S application on the total glucosinolate (GSL) content in the edible parts of vegetable turnip rape cv. No. 21 (Brassica rapa L.) was studied. Plants were grown with different amounts and ratios of Nand S in a glasshouse. The individual GSLs present were quantified by HPLC. The total GSL content ranged widely from 28.4 to 80.0 mmol kg−1 DW. In the 10 mm N (N1) treatment with three levels of S (0.5, 1, and 2 mm), the total GSL content linearly increased by larger S application for all harvest dates. The total GSL content in the 10 mm N with 0.5 mm S (N1S1/2) treatment was the lowest. On the other hand, even though the total GSL content in the 30 mm N (N3) treatment also increased by larger S application, there was no significant difference between the 30 mm N with 1 mm S (N3S1) treatment and the 30 mm N with 2 mm S (N3S2) treatment. The total GSL content increased gradually with harvest dates in the N3 treatments. Among the 8 GSLs identified, gluconapin and glucobrassicanapin, which...
80 citations
TL;DR: In this article, the authors investigated the relationship between the disease severity of clubroot caused by Plasmodiophora brassicae, the soil pH value and the concentration of exchangeable calcium associated with liming under controlled density of resting spores.
Abstract: Relationships between the disease severity of clubroot caused by Plasmodiophora brassicae, the soil pH value and the concentration of exchangeable calcium associated with liming were investigated under controlled density of resting spores. Disease indices were lower in the plots treated with lime than in the control plots without lime application. The disease index was significantly lower when lime materials were mixed two weeks before sowing compared with four weeks before sowing. The reduction rate of the disease index was larger for a concentration of 2.0 g kg−1 than 1.0 g kg−1 of lime in soil. The density of the resting spores in soil at the time of sowing was significantly reduced by liming. The reduction rate was 17–31 % for calcium cyanamide, 12–29% for dolomite, and 20–39% for calcium carbonate compared with the control plot. It was suggested that the disease severity was influenced by both the soil pH and the content of exchangeable calcium in soil based on the analysis of covariance.
71 citations
TL;DR: In this article, various combinations of 1-week culture with 5 or 0 mm nitrate were applied using 13-d-old soybean seedlings during three successive weeks, and the treatments were designated as 0-0-0, 5-5-5, 55-0 and 5 5 5 0.
Abstract: Nodulated soybean (Glycine max. (L) Merr. cv. Williams) plants were hydroponically cultured, and various combinations of 1-week culture with 5 or 0 mm nitrate were applied using 13-d-old soybean seedlings during three successive weeks. The treatments were designated as 0-0-0, 5-5-5, 5-5-0, 5-0-0, 5-0-5, 0-5-5, and 0-0-5, where the three sequential numbers denote the nitrate concentration (mm) applied in the first-second-third weeks. The size of the individual nodule was measured periodically using a slide caliper. All the plants were harvested after measurement of the acetylene reduction activity (ARA) at the end of the treatments. In the 0-0-0 treatment, the nodules grew continuously during the treatment period. Individual nodule growth was immediately suppressed after 5 mm nitrate supply. However, the nodule growth rapidly recovered by changing the 5 mm nitrate solution to a 0 mm nitrate solution in the 5-0-0 and 5-5-0 treatments. In the 5-0-5 treatment, nodule growth was completely inhibited i...
52 citations
TL;DR: The succession of responsible microbiota during the composting process of rice straw was studied for 145 d in relation to the changes in the organic constituents of RS, indicating the co-contribution of Gram-positive and Gram-negative bacteria and fungi in the decomposition process at this stage.
Abstract: The succession of responsible microbiota during the composting process of rice straw (RS) was studied for 145 d in relation to the changes in the organic constituents of RS. During the composting process, the C / N ratio of RS decreased from 56 to 22. On a C basis, the relative contents of lipid, water-soluble organic matter (WSOM), hemicellulose, cellulose, and lignin fractions in RS changed from 5.6, 8.9, 32.9, 17.9, and 34.0%, to 7.3, 5.8, 30.7, 3.8, and 51.1%, respectively, indicating that the cellulose fraction was mainly decomposed in the composting process. Biomass C accounted for 18.3% (on day 75 when the total amount of phospholipid fatty acids (PLFAs) reached a peak) and 11.5% (at the end of composting) of the total C of RS under the composting process. As for PLFAs, the biomarkers of fungi and Gram-negative bacteria predominated in the RS material used. At the thermophilic stage (the first 2 weeks), biomarkers of Gram-positive bacteria and actinomycetes predominated. After the thermoph...
48 citations
TL;DR: In this article, an analysis of rice plants grown under salt stress conditions was performed, and it was found that excessive NaCl in the rooting solution enlarges the apoplastic pathways, which facilitates Na+ intrusion into the xylem vessels, resulting in an excessive accumulation of Na+ in rice shoots.
Abstract: Sodium transport to the shoots of rice (Oryza sativa L.) plants grown under salt stress conditions was characterized. The rate of Na+ transport to shoots increased exponentially depending on the increase in the NaCl concentration of the rooting solution, however, the rates were independent of the plant transpiration. Excessive NaCl in the rooting solution was found to enhance apoplastic transport in rice plants by using the apoplastic dye, 3-hydroxy-5,8,10-pyrene trisulfonic acid (PTS) and Fluostain I (also known as Calcoflour White M2R New). The results suggest that excessive Na+ in the rooting solution enlarges the apoplastic pathways, which facilitates Na+ intrusion into the xylem vessels, resulting in an excessive accumulation of Na+ in rice shoots.
43 citations
TL;DR: In this article, two pH indicator dyes, bromo cresol green (BCG) and Bromo phenol blue (BPB), were used to develop a new method for the isolation of microorganisms that solubilize iron and aluminum phosphates based on the fact that the Solubilization of iron and aluminium phosphates was associated with the decrease of the pH.
Abstract: Two pH indicator dyes, bromo cresol green (BCG) and bromo phenol blue (BPB) were used to develop a new method for the isolation of microorganisms that solubilize iron and aluminum phosphates based on the fact that the solubilization of iron and aluminum phosphates was associated with the decrease of the pH. BCG was found to be superior to BPB in terms of clarity and visibility. The use of Reyes's basal medium plus dye was found to be preferable to that of Pikovaskaya's medium plus dye in terms of halo zone formation. These results indicated that Reyes's basal medium plus BCG is the best medium for the isolation of iron and aluminum phosphates-solubilizing microorganisms. Four efficient iron phosphate solubilizers and five efficient aluminum phosphate solubilizers were isolated on Reyes's basal medium containing FePO4 and AlPO4, respectively, plus BCG.
42 citations
TL;DR: In this paper, the water balance and runoff and infiltration losses of nutrients in a paddy field plot located in southern Korea were investigated, where field monitoring was carried out during the cropping season from May 1, 1999 to September 30, 2000.
Abstract: The study was carried out to investigate the water balance and runoff and infiltration losses of nutrients in a paddy field plot located in southern Korea. Field monitoring was carried out during the cropping season from May 1, 1999 to September 30, 2000. The soil of the experimental paddy field belonged to the Jisan series (SiL; fine loam, mixed, mesic Fluventic Haplaquepts) covering on area of 5,000 m2 (100 m × 50 m). The measured input quantities of N and P into the paddy field were as follows: 122 and 140 kg N ha−1 and 29 and 30 kg P2O5 kg ha−1 from chemical fertilizer, 20 and 28 kg N ha−1 and 0.35 and 0.36 kg P ha−1 from precipitation, and 26 and 35 kg N ha−1 and 0.57 and 0.72 kg P ha−1 from irrigation water, respectively. The measured outputs of N and P during the study period were as follows: 48 and 52 kg N ha−1 and 1.1 and 1.6 kg P ha−1 from runoff water, and 9 and 12 kg N ha−1 and 0.04 and 0.05 kg P ha−1 from infiltration. The runoff loading was the highest in June, presumably because of...
39 citations
TL;DR: Results indicate that SA is directly involved in signal transmission in the autoregulation, and that SA or the SAR induced by SA stimulates the autOREgulation of nodulation in soybean.
Abstract: Soybean plant is characterized by a systemic autoregulatory control system of nodulation (autoregulation) by initial infection with rhizobia, and plants commonly display a systemic acquired resistance (SAR) to pathogenic microbe infection related to salicylic acid (SA) signal transmission. We investigated the effect of exogenous SA supply on soybean nodulation to determine whether SA affects the autoregulation of nodulation. Seedlings of the hypernodulating mutants NOD1-3, NOD2-4 and their parent cv. Williams were treated or not treated (control) with a 100 μmS-SA solution at 5 d before the inoculation of Bradyrhizobium japonicum strain USDA110. The nodule dry weight and the number of nodules of the wild type soybean Williams exhibiting autoregulation drastically decreased by the addition of 100 μm SA. The decrease in the nodule number was not caused by the reduction of the rhizobium number in the medium. Salicylic acid inhibited only early nodule formation and did not affect the growth of formed...
TL;DR: In this article, the authors evaluated the effect of the application of Si (in the form of silica gel) on the growth, yield, and canopy structure of rice plants grown under field conditions.
Abstract: In many studies using solution culture or pot culture it was reported that dry matter and yield production of rice plants can be improved by silicon application. There is limited information, however, on field-grown rice. The purpose of this study was to evaluate the effect of the application of Si (in the form of silica gel) on the growth, yield, and canopy structure of rice plants grown under field conditions. The results obtained were as follows: 1) No significant differences in the growth and yield of rice plants with and without Si application were observed under high availability of SiO2. However, the canopy structure of the rice plants was improved by Si application. The distance between the desirable position and the actual position of the top leaf was shorter in the + Si treatment than in the − Si treatment at the maximum tiller number stage. 2) The relative light intensity was higher in the + Si treatment than in the − Si treatment at the maximum tiller number stage, irrespective of the...
TL;DR: In this article, the authors determined the oxidation rate of Cr(III) to Cr(Vl) and different forms of Cr (VI), labile (adsorbed and solution) and solid forms were determined, in 11 moist soil samples collected from four Texas soil series (Silawa, Boonville, Burleson, and Pledger soils).
Abstract: Land disposal of chromium-containing wastes constitutes an environmental risk where oxidation of Cr(III) to Cr(VI) may occur. The oxidation rate of Cr(III) to Cr(Vl) and different forms of Cr(VI), labile (adsorbed and solution) and solid forms were determined, in 11 moist soil samples collected from four Texas soil series (Silawa, Boonville, Burleson, and Pledger soils). The Cr oxidation rate increased with increasing content of reactive manganese (Mn) oxides and decreasing pH of the soils as follows: Pledger > Silawa > Boonville ≅ Burleson. Concentration of labile Cr(VI) in the soils was apparently controlled by barium chromate (BaCrO4) without barite (BaSO4) or by Cr-substituted barite [Ba(S,Cr)O4] in the presence of barite. The Boonville soil contained barite and a much lower concentration of labile Cr(VI) than the other soils. Based on the Cr oxidation rate and forms of Cr(VI), soils with a low content of reactive Mn oxide, high pH, and barite was recommended for field testing as safe land di...
TL;DR: Morpho-physiological characterization of isolates revealed that BO-1 and BO-5 showed a similar colony color in potato sucrose agar slants, produced bubbles in a modified semi-solid medium, acidified the medium, and displayed similar characteristics using the API 20NE rapid diagnostic kit.
Abstract: The population density of endophytic bacteria in the stem of field-grown sweet potato cultivars (Beniotome [BO], Koganesengan [KS], and Shiroyutaka [SYD in Miyakonojo, Miyazaki, Japan, ranged from ...
TL;DR: In this article, the effect of sewage sludge compost and chemical fertilizer application on the soil chemical properties, net N mineralization rates, CO2 evolution rates, microbial biomass C and N, a non-leaching experiment was conducted under controlled conditions of temperature (25°C) and moisture content (80% wHC).
Abstract: To determine the effect of sewage sludge compost and chemical fertilizer application on the soil chemical properties, net N mineralization rates, CO2 evolution rates, microbial biomass C and N, a non-leaching experiment was conducted under controlled conditions of temperature (25°C) and moisture content (80% wHC) using 2 types of soils that had been previously treated with sewage sludge composts or chemical fertilizer during short or long periods of time. The incubation lasted for 90 d. The treatments included: soils samples taken from 3 plots, each receiving sewage sludge compost with rice husk (RH), sewage sludge compost with sawdust (SD), and chemical fertilizer (CF), each applied at the rate of 200 kg N ha−1 biannually for 22 years (Tama farm) and 2 years (Chiba farm). The application of SD and RH led to a significant increase in the total N and C and soluble organic C reservoirs of the two soil types regardless of the application history. Soil pH was always higher in the sludge-treated soils...
TL;DR: In this paper, food wastes were composted with saw dust, dried paper mill sludge, and decayed wood dust to reduce the volume of wastes and to produce a stable organic soil amendment.
Abstract: Food wastes were composted with saw dust, dried paper mill sludge, and decayed wood dust to reduce the volume of wastes and to produce a stable organic soil amendment. To determine the stability for agricultural utilization, the compost maturity was evaluated using physical, chemical, and biological parameters. Temperature of the inner compost heap remained high at over 50°C during the 80 d of composting, but the chemical and physical parameters apparently changed between 30 and 50 piling d: pH was a weakly acidic of the initial stage and neutral after 30 d of composting. The C / N ratio decreased to less than 12 after 65 d of composting, but the C / N ratio of the products was less than 0.5 time that of the initial value after 35 d of composting. Reducing sugar contents changed significantly between 40 and 45 d of composting, and the Y value that indicated color changes of the water extracts decreased and became stabilized at around 3 after 50 d of composting. Ring types and color on circular pa...
TL;DR: In this article, the effects of 3 oxides (Fe, Al, and Mn oxides) and 3 clay minerals (kaolin, montmorillonite, and allophane) on the adsorption and subsequent kinetic properties of acid phosphatase were compared.
Abstract: Abstrac The effects of 3 oxides (Fe, Al, and Mn oxides) and 3 clay minerals (kaolin, montmorillonite, and allophane) on the adsorption and subsequent kinetic properties of acid phosphatase were compared. The amount of enzyme adsorbed by the oxides and clay minerals followed the order: montmorillonite ≫ kaolin > Mn oxide > Fe oxide > Al oxide ≫ allophane. The adsorption isotherms of the enzyme on the oxides and clay minerals, except for montmorillonite and allophane, fitted the Langmuir equation. The activity of the enzyme immobilized by the inorganic components studied was in the order of allophane > kaolin > Fe oxide > montmorillonite > Al oxide ≒ Mn oxide. Compared to the free enzyme, the V max, Km, and V max / K m values of the immobilized enzyme decreased, increased, and decreased, respectively. Among the oxides or clay minerals, the higher the ability of the inorganic components to adsorb the enzyme, the lower the value of the V max / K m ratio of the immobilized enzyme. These findings suggest that t...
TL;DR: A field experiment was conducted to examine N2O emissions from three upland cropping systems, which included 0, 1, or 2 legumes cultivated in annual rotations in China as discussed by the authors.
Abstract: Nitrous oxide is an important greenhouse gas and it is considered that cropping systems may considerably affect N2O emissions. A field experiment was conducted to examine N2O emissions from three upland cropping systems, which included 0, 1, or 2 legumes cultivated in annual rotations in China. The three cropping systems were as follows: 1) winter fallow followed by summer upland rice, 2) winter rape followed by summer peanut, and 3) winter pea followed by summer soybean. Each cropping system, for both winter and summer crops, included two fertilization treatments 1) N, P, and K application at the local conventional rate, and 2) P and K application at the local conventional rate without N. A total of six treatments consisting of three replicates (5 × 5 m plots) were used according to a random block design in the sub-tropical region (Udic ferrisols) of China. N2O emissions were measured frequently from the planting day to harvest day along with the soil temperature and moisture. This experimental ...
TL;DR: In this article, Humic acid-like (HA-like) and core-humic acid like (core-HA) were characterized during the high-rate composting process by CP-MAS 13C NMR, pyrolysis-gas chromatography (GC)/mass spectrometry (MS), and elemental analysis.
Abstract: Humic acid-like (HA-like) and core-humic acid-like (core-HA-like) were characterized during the high-rate composting process by CP-MAS 13C NMR, pyrolysis-gas chromatography (GC)/mass spectrometry (MS), and elemental analysis. Results obtained indicated that humification proceeded through a relative concentration of aromatic fractions due to the faster degradation of the O-alkyl and alkyl fractions. Core-HA-like, after purification of the parent material, showed a large reduction of the O-alkyl fraction in terms of HA-like. We concluded that HA-like consisted of refractory organic molecules, such as lignin and biopolymers, which formed a stable structure (core-HA-like) coated with degradable material associated with the core by weak physical association, ether or ester bounds.
TL;DR: The dose response curve (DRC) was determined to indicate the relationship between the disease index and these parameters for predicting the disease severity for each field and is useful for estimating the potential disease severity in agricultural fields with different soils and different plants.
Abstract: The severity of clubroot disease caused by Plasmodiophora brassicae Woron. depended on the density of resting spores in soil, soil type, soil pH, and host susceptibility. The dose response curve (DRC) was determined to indicate the relationship between the disease index and these parameters for predicting the disease severity for each field. DRC patterns varied with the soil types and even among soils of the same type depending on the sampling areas. Disease incidence was lower in the soils adjusted to a higher pH than in those at the initial pH. DRC patterns were also influenced by plant species or cultivars. The DRC is useful for estimating the potential disease severity in agricultural fields with different soils and different plants and essential for the development of an integrated pest management (IPM) strategy for the control of clubroot disease.
TL;DR: In this article, the main objective was to increase the productivity of soybean [Glycine max (L.) Merr. cv. Enrei] seed by deep placement of controlled release nitrogen fertilizers and by the application of different methods of inoculation of bradyrhizobia.
Abstract: The main objective of this study was to increase the productivity of soybean [Glycine max (L.) Merr. cv. Enrei] seed by deep placement of controlled release nitrogen fertilizers and by the application of different methods of inoculation of bradyrhizobia. Ten days old seedlings in an inoculated paper pot (IPP), in a non-inoculated paper pot (NIPP), and those grown in a vermiculite bed without paper pot (DT) were transplanted to an upland field converted from a drained paddy field in Nagaoka. In addition to the basal application of 16 kg N ha−1 in the surface layer (Control), deep placement of 100 kg N ha−1 of urea (Urea), 100-day type coated urea (CU-100), and calcium cyanamide (CaCN2) treatments were applied at the depth of 20 cm. In the IPP method, a significantly higher seed yield was obtained with the deep placement of CaCN2 and CU-100 compared with the Urea and Control treatments. A similar tendency was observed for the DT and NIPP methods. Among the same N fertilizer treatments, the seed yie...
TL;DR: In this article, the comparative efficiency of five MSL systems as a function of alternative organic materials (i.e., sawdust, kenaf, corncob, rice straw, and rice straw) was investigated.
Abstract: Multi-soil-layering (MSL) system can be applied to wastewater treatment. The component of an MSL system can be varied as a function of site-specific availability of materials. This study investigates the comparative efficiency of five MSL systems as a function of alternative organic materials (Japanese sawdust, Thai sawdust, rice straw, kenaf, and corncob). The MSL systems were set up in 15 × 50 × 100 cm boxes consisting of “soil mixture blocks” alternated with a zeolite layer. The February–May 1999 results indicated that all the MSL systems under a non-aeration regime effectively reduced the biochemical oxygen demand (BOD5) and removed soluble reactive phosphorus (SRP) with percentages ranging from 88.0–99.8 and 92.5–100, respectively. From January to September 2000 when an on-off aeration regime was adopted, the MSL treatments comprising rice straw, kenaf, and corncob continued to effectively reduce BOD5 and remove SRP. On the other hand, the efficiency of Japanese sawdust and Thai sawdust MSL ...
TL;DR: In this paper, an acid soil was treated with alum sludge from a water purification plant at 0 to 18% rate, and Indian mustard was grown on the treated soil in a greenhouse for 5 weeks, and irrigated with pH 4 water during growth.
Abstract: Land application of alum sludge has been considered to be an economical disposal method. However, its negative effects on the environment have been a cause for concern. In one example, an acid soil was treated with alum sludge from a water purification plant at 0 to 18% rate. Indian mustard was grown on the treated soil in a greenhouse for 5 weeks, and irrigated with pH 4 water during growth. Changes in the soil properties, leachate chemistry, plant growth, and plant uptake of elements by the sludge treatment were determined. The sludge treatment increased the buffer capacity to acidity, hydraulic conductivity, water-holding capacity, and phosphate adsorption of the soil and decreased the bulk density and mobility of small particles. The sludge treatment reduced the leaching of Al, Mg, K, Na, and Mn but increased leaching of Ca. The sludge treatment also increased the amount of biomass and enhanced root elongation. The plant absorbed a lower amount of cations and P, but a larger amount of Ca with...
TL;DR: It is suggested that a balance between the K+ / Na+ ratio and proline accumulation may be the factor involved in determining the salt tolerance of plant cells.
Abstract: The concentrations of K+, Na+, and proline and the ratio of K+ to Na+ (K+ / Na+) were analyzed in NaCl-unadapted and NaCl-adapted tobacco (Nicotiana tabacum) cells in suspension culture. At 3 to 5 d after inoculation, the NaCl-unadapted cells cultured in 100 mmol L−1 NaCl saline culture medium (Na100 medium) accumulated 28.7 mmol L−1 proline with a low ratio of K+ to Na+ (= 2.8) and the NaCl-adapted cells cultured in the Na100 medium contained 6.28 mmol L−1 proline with a high K+ / Na+ ratio (≧ 7.5). The contents of amino acids for the NaCl-adapted cells in the Na100 medium were similar to those for the NaCl-unadapted cells in a modified LS medium (standard medium). At 14 d after inoculation, the NaCl-unadapted cells in the Na100 medium contained 4.77 mmol L−1 proline and restored the K+ / Na+ ratio from 2.8 to 6.2. These results indicate the presence of a negative correlation between the K+ / Na+ ratio and proline accumulation and suggest that a balance between the K+ / Na+ ratio and proline acc...
TL;DR: In this article, the authors found that Petasites japonicus v. giganteus (Japanese butterbur) and Polygonum cuspidatum (Japanese knotweed) exude a large quantity of guttation fluid from the leaf edge.
Abstract: Petasites japonicus v. giganteus (Japanese butterbur) and Polygonum cuspidatum (Japanese knotweed) exude a large quantity of guttation fluid from the leaf edge. The concentrations of Ni and Mn in the guttation fluid from Petasites japonicus v. giganteus grown on ultramafic soil were 2.24 (Ni) and 0.32 (Mn) mg L−1, respectively, on the average, whereas those in the guttation fluid from Polygonum cuspidatum were 0.22 (Ni) and 3.13 (Mn) mg −1, respectively. The Ni concentration in the leaves of Petasites japonicus v. giganteus was about 5 times as high as that of Polygonum cuspidatum, especially at the leaf edges, and the Mn concentration in the leaves of Polygonum cuspidatum was about 6 times as high as that of Petasites japonicus v. giganteus. Thus, the concentrations of Ni and Mn in both the guttation fluid and leaves of Petasites japonicus v. giganteus were opposite to those of Polygonum cuspidatum. The contents of K, Mg, and Ca in the guttation fluid from Petasites japonicus v. giganteus were h...
TL;DR: In this article, the proportion of biologically fixed nitrogen (NDFa) to the plant total nitrogen uptake was determined by 15N dilution and natural 15N abundance (δ15N) techniques using the estimated %Ndfa by the sugarcane cv. NiF-8 under field lysimeter conditions ranged from 32 to 38% at 6 months after planting (MAP) and from 27 to 34% at 7 MAP.
Abstract: The high population of endophytic diazotrophs in the stalk of the Japanese sugarcane cultivar NiF-8 described in our previous report suggests the possible significant contribution of biological nitrogen fixation (BNF) to the crop nitrogen nutrition. To estimate the amount of BNF in this cultivar, the proportion of biologically fixed nitrogen (%Ndfa) to the plant total nitrogen uptake was determined by 15N dilution and natural 15N abundance (δ15N) techniques. Using the δ15N method, the estimated %Ndfa by the sugarcane cv. NiF-8 under field lysimeter conditions ranged from 32 to 38% at 6 months after planting (MAP) and from 27 to 34% at 7 MAP. With the 15N dilution method, the estimated %Ndfa by the sugarcane plants was 26.0% for the roots, 14.1% for the stem, and 20.5% for the leaves. These results indicate that the sugarcane cv. NiF-8 obtained part of its nitrogen requirements from BNF.
TL;DR: In this article, differences in nitrate and oxalate contents in different parts (flushes, leaves, stems, and roots) and in four types of Japanese green tea (normally steamed and heavily steamed Sencha, Gyokuro, and Tencha) were examined.
Abstract: To analyze the utilization of nitrate and synthesis of oxalate in tea plants Camellia sinensis L., differences in nitrate and oxalate contents in different parts (flushes, leaves, stems, and roots) and in four types of Japanese green tea (normally steamed and heavily steamed Sencha, Gyokuro, and Tencha) were examined. Nitrate content was high only in fibrous roots (0.25 g NO3 − kg−1 DW) and very low in other parts (< 0.06 g NO3 − kg−1 DW). The highest content of water-soluble oxalate was detected in flushes, whereas that of crystal oxalate (calcium oxalate) in mature leaves. Oxalate was also detected in the xylem sap. These findings suggest that oxalate, synthesized at the time of nitrate reduction in fibrous roots, is transported to flushes and leaves and then accumulates in mature leaves as crystal oxalate. There were no significant differences between the nitrate and oxalate contents of the normally steamed and heavily steamed types of Sencha, which were produced by steaming for 30 to 60 s and...
TL;DR: In this paper, the distribution of sclerotium grains, which are the resting bodies formed by fungi species, was studied in 5 Andosol profiles in central Japan, and the results indicated that the status of active Al in soils is an important factor for scleroteium development.
Abstract: The distribution of sclerotium grains, which are considered to be the resting bodies formed by fungi species, was studied in 5 Andosol profiles in central Japan Sclerotium grains were detected in the surface A and buried A horizons of nonallophanic (Alp / Alo > 05) soils but not in allophanic (Alp / Alo < 05) soils The maximum density of the sclerotium grains in each profile was approximately 25 g kg−1 A highly positive relationship was observed between the mean weight of the sclerotium grains and the content of exchangeable aluminum (Al3+) in soils Aluminum concentration inside of the sclerotium grains was confirmed by energy dispersive X-ray spectrometer (EDS) analysis The results obtained suggest that the status of active Al in soils is an important factor for sclerotium development
TL;DR: It is suggested that these Lupinus plants did not induce pre-symbiotic hyphal growth of arbuscular mycorrhizal fungi but inhibited it.
Abstract: Effect of root exudates of Lupinus plants on hyphal growth of arbuscular mycorrhizal (AM) fungus was investigated in order to elucidate the failure of mycorrhizal colonization in nonhost plants. Four species of Lupinus were grown in solution culture and root exudates were collected. Spores of Gigaspora margarita were incubated with the root exudates. Hyphal length in the root exudates of L. luteus, L. aridus, and L. cosentini was shorter than that of the control treatment, irrespective of the P status of Lupinus plants. Numbers of hyphae exhibiting branching were lower in the root exudates of L. luteus and L. cosentini than in those of the controls. It is suggested that these Lupinus plants did not induce pre-symbiotic hyphal growth of AM fungi but inhibited it.
TL;DR: In this article, the authors measured the concentrations of dissolved N2O, CH4, and CO2 in pipe drainage, seepage, and stream water in a livestock farm located in Hokkaido, Japan.
Abstract: We confirmed that multiple phase equilibration could be applied to the simultaneous determination of the concentrations of dissolved N2O, CH4, and CO2. To investigate the presence of indirect greenhouse gas emissions, we measured the concentrations of dissolved N2O, CH4, and CO2 in pipe drainage, seepage, and stream water in a livestock farm located in Hokkaido, Japan. Large spatial and seasonal variations in the gas concentrations in the pipe drainage and seepage were observed: the concentrations of the dissolved gases ranged from 0.06 to 95.2 μg N2O-N L−1, from 0.03 to 3,400 μg CH4-C L−1, and from 3.34 to 53.9 mg CO2-C L−1. Almost all the concentrations were supersaturated, indicating the possibility of indirect N2O, CH4, and CO2 emissions from the farm. The N2O and CO2 concentrations in the stream water were near equilibrium with ambient air and were almost constant from the upstream to the downstream. However, the concentration of dissolved CH4 was remarkably higher in the lower part of the s...