Onion fly egg distribution in soil: a new sampling method and the effect of two granular insecticides

Tests were carried out in a screenhouse to determine the potential of a microsporidian pathogen,Nosema marucae (Microspora: Nosematidae), for the control of the spotted stalk borer,Chilo partellus (Lepidoptera: Pyralidae), on sorghum. Foliar application of an aqueous suspension ofN. marucae spores on egg batches pasted on the sorghum plants reduced leaf-damage in plants in the protected plots, and increased the proportion of plants with fully- and partially formed heads compared to unsprayed plots. Further, there was less tunnelling and fewer larvae in the sprayed plots. The pathogen also reduced pest infestation and damage to plants when the plots were infested with newly emerged larvae instead of eggs.N. marucae has a potential to controlC. partellus.     

The chemical characteristic and distribution of brassinosteroids in plants

Brassinosteroids represent a class of plant hormones with high-growth promoting activity. They are found at low levels in pollen, anthers, seeds, leaves, stems, roots, flowers, grain, and young vegetative tissues throughout the plant kingdom. Brassinosteroids are a family of about 60 phytosteroids. The article gives a comprehensive survey on the hitherto known brassinosteroids isolated from plants. The chemical characteristic of brassinosteroids is also presented.     

Distribution pattern of anthocyanidins and anthocyanins in polygonaceous plants

Forty-six polygonaceous plants were examined regarding the nature and amount of anthocyanidins which were obtained as the HCl-hydrolyzate of leaf proanthocyanidins. All of the plants examined contained cyanidin in common in their hydrolyzed leafextracts. From this survey, at least three groups of plants may be distinguished; the first containing only cyanidin, the second delphinidin in addition to cyanidin and the third an unknown anthocyanidin (called PA-X) and cyanidin. Of the plants examined,Polygonum cuspidatum leaves yielded cyanidin in the largest amounf. There were no geographical and seasondl variations of the distribution pattern of pigments in the plants, and also no variation of anthocyanidin-types was observed in young and mature leaves. A further survey of anthocyanins in the plants revealed that delphinidin glycosides are present in the sepals ofPolygonum nepalense andP. thunbergii.     

热带森林乔木种群分布格局及其研究方法的比较

应用样地个体数为基础的方差／均值比率、Ｍｏｒｉｓｉｔａ分散指标,以及以个体距离为基础的最近邻体法、复合个体距离分析法对海南岛吊罗山山地雨林８个主要种群分布格局进行了比较研究．结果表明,８个种群为聚集或随机分布,４种测定方法中以复合个体距离分析法较好．     

The distribution pattern of rhesus and Assamese monkeys in Nepal

Surveys of the distribution and some ecological characteristics of rhesus monkeys (Macaca mulatta) and Assamese monkeys (M. assamensis) in Nepal were conducted during 234 days in 1976, 1978, and 1984. Rhesus monkeys dominated in the tropical, subtropical, and temperate forests below 3,000 m a.s.l. all over Nepal. Assamese monkeys were patchily distributed along rivers in the tropical and subtropical areas. Both species principally utilized forests parapatrically. The mean troop size of rhesus monkeys (29.5) was significantly larger than that of Assamese monkeys (19.1). Discontinuous distribution of Assamese monkeys probably appeared as a result of the expansion of rhesus monkey distribution in the mid- and late-Pleistocene. Because of small distribution areas and small numbers of monkeys, urgent conservation policy must be pursued.     

Movement and chemical distribution of isotopic nitrogen down the soil profile

Summary The downward movement and accumulation of added fertilizerin situ was studied for fine-textured, loess-terrace derived soils of Rimski Sanchevi, Navisad, Yugoslavia. Three N-treated, fallowed plots from a nitrate movement experiment were selected for this study. Soil samples were obtained upto 200 cm depth at 20 cm interval and the isotope ratio analyses were done for different forms of residual N.Fertilizer moved down the profile upto 140 cm depths and the accumulated residual N in the profile was about 55 percent of total added¹⁵N. The maximum accumulation of added fertilizer was at 0–20 cm depth (98 kg/ha) followed by 60–80 cm (32 kg/ha) depth. The fertilizer¹⁵N converted to alkali-stable (amino acid) and alkali-labile (amino sugar)-N forms were about 17 and 12 percent respectively. Only 0.41 percent of added fertilizer was converted to fixed NH₄–N. It is hoped that these findings will help the proper management of nitrogen fertilization to reduce the risk of ground water pollution.     

Uptake and distribution of phosphorus in tomato plants

Summary The uptake and distribution of phosphorus was examined in tomato plants, cv. Kirdford Cross, grown in peat to which phosphate was added (P₂) or omitted (P₁). The plants received a liquid feed containing either a high (N₂) or low (N₁) concentration of ammonium nitrate. Initially, all plants were grown in peat containing an intermediate level of phosphate.There was a rapid net export of P from the leaves of plants transferred to the P₁ medium resulting in deficiency symptoms before the fruit on the first truss had ripened. Most of the P absorbed by 11-week-old plants in the N₁P₂ and N₂P₂ treatments was located in the developing fruit, in the laminae of the mature leaves and in the lower parts of the stem. In the P₁ treatments, the lowest fruit truss was the dominant sink for the limited supply of P, but there was also a significant concentration of P in the shoot apex and in the laminae. Increasing the supply of N to plants in the P₂ treatment promoted the transport of P to the shoot and to the fruit trusses and also increased the total P uptake. However, plants in the N₂ treatment required a significantly higher level of tissue P to prevent the symptoms of P deficiency occurring in the laminae. Generally, symptoms occurred in laminae of mature leaves containing less than 0.13 per cent P. Increases in concentration of tissue P in response to raising the level of applied P were greatest in the petioles of the mature leaves, and it is suggested that these petioles are the most suitable tissues for the assessment of the P status of tomato plants.     

Immunocytochemical studies on the distribution pattern of daunomycin in rat gastrointestinal tract

The cancer drug daunomycin is used in treatment of leukemia but possesses severe side effects that involve the gastrointestinal tract. We therefore used a newly developed immunocytochemical procedure to determine the distribution of DM in the gastrointestinal tracts of rats after i.v. injection. Two hours after injection, DM was diffusely distributed in nuclei and most parts of the cytoplasm of intestinal epithelial cells. The cytoplasmic immunoreactivity for DM was most pronounced in small granules of the apical cytoplasm. Sixteen hours after injection, DM immunostaining was by and large absent in the villous epithelium but persisted in the intestinal crypts. In addition, staining was also detected in endothelial cells, scattered cells of the lamina propria and in smooth muscle cells. After 5 days, only little staining for DM remained. Similar findings were made in the colon. In the gastric mucosa, DM accumulation persisted at 16 h in some glandular cells but was lost from the surface epithelium. No staining was detected in saline-injected control rats. The distribution of DM accumulation correlated partially with the distribution of apoptotic cells as detected by the TUNEL procedure. Our results pinpoint that DM may exert prolonged effects on glandular and regenerative cells of the gastrointestinal tract—an observation that may explain the gastrointestinal toxicity of the drug. It seems possible that DM accumulation in surface epithelial cells is rapidly cleared through drug transporters.     

神农架地区珍稀植物沿河岸带的分布格局及其保护意义

在神农架香溪河流域从源头到河口的不同海拔高度沿河岸带共设置 4 0个与河流方向平行的10 0m× 10m的样带 ,进行了植物群落学调查研究 .结果表明 ,沿河岸带分布有珍稀植物 14种 ,占神农架地区珍稀植物总数的 4 2 .4 % .这些珍稀物种主要分布在海拔 12 0 0～ 180 0m山地常绿阔叶落叶阔叶混交林带 ,珍稀植物种类的物种丰富度在中等海拔高度上最大 .珍稀植物的种类可划分为低海拔、中等海拔和高海拔 3组 .针对珍稀植物的分布特点 ,明确指出应重视河岸带在生物多样性、尤其是珍稀物种保护方面的重要作用 .     

Geographic distribution patterns and status assessment of threatened plants in China

Large scale heterogeneous distribution of biodiversity has become a hot topic for ecologists and conservationists. A threat status assessment combined with geographic distribution patterns of threatened plants in China has been conducted at a national scale in this study based upon a distribution database that refers to both specimen records and published references. Currently, 302 threatened plant species are cataloged in the “National Protected Key Wild Plants” in China belonging to 92 families and 194 genera. Results of the assessment according to the Categories and Criteria system of The World Conservation Union (IUCN) Red List indicate that three species have been assessed as Extinct in Wild (EW) while a further 79, 99 and 112 species have been assessed as Critically Endangered (CR), Endangered (EN), and Vulnerable (VU), respectively. Distribution patterns of threatened plants were analyzed with GIS to identify areas of high species diversity. It was found that threatened plant species occur unevenly within counties and are concentrated in the following eight hotspots: the central and southern Hengduanshan mountain area; the southeast regions of Yunnan as well as Xishuangbanna and southwestern Guangxi; the southern Hainan island; the border mountainous regions of Guizhou, Hunan and Guangxi provinces; the mountainous regions of southwestern Hubei and northern Hunan; southwestern Zhejiang and western Fujian; central Sichuan and southern Gansu; and the western mountains of Guangdong. Moreover, the 12 counties with the greatest number of threatened plant species represent cumulatively more than 50% of the total listed species and, therefore, are the regions in China that should be prioritized for conservation efforts. By overlapping the map of threatened plant species with the distribution of national nature reserves, a gap was identified in protected areas. This research will ultimately provide insights for prioritizing biodiversity conservation as well as processing the mechanisms of distribution patterns.     

Identification of hake distribution pattern and nursery grounds in the Hellenic seas by means of generalized additive models

A time series of hake abundance data obtained from the “MEDITS” experimental surveys carried out in the Greek seas from 1996 to 2006 have been modeled by means of Generalized Additive Models (GAMs), as functions of spatial and temporal variables, including sampling position (latitude–longitude interaction), depth, and year. All variables were highly significant but most of the variation was explained by the sampling position and the depth. Total abundance was higher in the 100–450 m depth zone, while juveniles showed preference for shallower waters, being more abundant from 100 to 320 m. Model predictions were used to generate density distributions maps, which revealed that total abundance is relatively higher in the western part of the Aegean Sea and in the eastern part of the Cretan Sea, while its maximum values are expected in the Saronikos Gulf. Nursery grounds are restricted in specific regions with the most important of them being in the Saronikos Gulf and its surrounding area. Guest editor: V. D. Valavanis Essential Fish Habitat Mapping in the Mediterranean     

Quantitative Analysis of the Chloroplast Molecular Chaperone ClpC/Hsp93 in Arabidopsis Reveals New Insights into Its Localization,Interaction with the Clp Proteolytic Core,and Functional Importance

The molecular chaperone ClpC/Hsp93 is essential for chloroplast function in vascular plants. ClpC has long been held to act both independently and as the regulatory partner for the ATP-dependent Clp protease, and yet this and many other important characteristics remain unclear. In this study, we reveal that of the two near-identical ClpC paralogs (ClpC1 and ClpC2) in Arabidopsis chloroplasts, along with the closely related ClpD, it is ClpC1 that is the most abundant throughout leaf maturation. An unexpectedly large proportion of both chloroplast ClpC proteins (30% of total ClpC content) associates to envelope membranes in addition to their stromal localization. The Clp proteolytic core is also bound to envelope membranes, the amount of which is sufficient to bind to all the similarly localized ClpC. The role of such an envelope membrane Clp protease remains unclear although it appears uninvolved in preprotein processing or Tic subunit protein turnover. Within the stroma, the amount of oligomeric ClpC protein is less than that of the Clp proteolytic core, suggesting most if not all stromal ClpC functions as part of the Clp protease; a proposal supported by the near abolition of Clp degradation activity in the clpC1 knock-out mutant. Overall, ClpC appears to function primarily within the Clp protease, as the principle stromal protease responsible for maintaining homeostasis, and also on the envelope membrane where it possibly confers a novel protein quality control mechanism for chloroplast preprotein import.     

Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

Three species, wheat, maize and cotton, were grown in pots and subjected to high (85–100% field capacity, _F), medium (65–85% _F) and low (45–65% _F) soil moisture treatments and high (700 l l^–1) and low (350 l l^–1) CO₂ concentrations. Biomass production, photosynthesis, evapotranspiration and crop water use efficiency were investigated. Results showed that the daily photosynthesis rate was increased more in wheat and cotton at high [CO₂] than in maize. In addition, differences were more substantial at low soil water treatment than at high soil water treatment. The daily leaf transpiration was reduced significantly in the three crops at the high CO₂ concentration. The decrease at low soil water was smaller than at high soil water. Crop biomass production responses showed a pattern similar to photosynthesis, but the CO₂-induced increase was more pronounced in root production than shoot production under all soil water treatments. Low soil water treatment led to more root biomass under high [CO₂] than high soil water treatment. CO₂ enrichment caused a higher leaf water use efficiency (WUE) of three crops and the increase was more significant in low than in high soil water treatment. Crop community WUE was also increased by CO₂ enrichment, but the increase in wheat and cotton was much greater than in maize. We conclude that at least in the short-term, C₃ plants such as wheat and cotton may benefit from CO₂ enrichment especially under water shortage condition.     

Effect of CPC,Brij-35, and SDBS Surfactants on the Adsorption and Movement of Carbofuran in Indian Soils

Laboratory studies were conducted to determine adsorption and movement of carbofuran in aqueous surfactant-free and surfactant [(cationic, cetyl pyridinium chloride (CPC), non-ionic, polyoxyethylene lauryl ether (Brij-35) and anionic, sodium dodecyl benezene sulphonate (SDBS)] solutions of different critical micellar concentrations (1/2 × CMC, 1.0 × CMC, and 2 × CMC) in four different Indian soils using batch shake and soil thin layer chromatography (soil TLC) techniques. The measured equilibrium adsorption isotherms were in agreement with the Freundlich equation. Higher adsorption of carbofuran in both systems was observed on FRI silt loam (FSL) soil followed by Alampur silt loam (ASL), Kalai loam (KL), and Bhoran sandy loam (BSL) soils, as anticipated from Freundlich constant K_F and distribution coefficient K_D, in surfactant-free systems and K_F* and K_D* in surfactant-soil-water systems. The adsorption of carbofuran in surfactant-soil-water systems followed the order cationic > anionic > non-ionic at all CMCs studied. The R_f values obtained from soil TLC studies confirmed the above order of adsorption. The K_D and K_D* values were used to evaluate remediation efficiency (K_D*/K_D) of surfactants. Non-ionic surfactant, Brij-35, and anionic surfactant, SDBS, are favorable for remediating soil contaminated with carbofuran as K_D*/K_D ratio is less than 1.     

Phytotoxicity and distribution of copper in tropical soil amended with sewage sludge and copper sulfate

Abstract

A greenhouse experiment was conducted to evaluate phytotoxicity and distribution of Cu in a tropical soil amended with sewage sludge (Sw) and copper sulfate (CuSO₄.5H₂O). Samples of a clay soil from the State of Paraná, Brazil were collected at depth of 0–20; 20–40 and 40–60 cm, and brought to the laboratory to be properly accommodated in experimental units (PVC tubes). The Cu treatments were performed by the application of Sw (10 t ha-¹) amended with Cu (SB-T), and by CuSO₄. H₂O (WB-T). Lettuce plants were cultivated in the amended soil in order to predict the toxicity of the Cu. The experiment was conducted for 70 days, and then the lettuce plants and soil samples were collected for analysis. A sequential method was used to separate soil Cu into following fractions: exchangeable, amorphous iron oxide bound, crystalline iron oxide bound, organic matter bound and residual bound. The experimental results showed that Fe, Zn, K, P, Cu and organic matter amounts of the soil increased with the treatment SB-T. The toxic phyto-available Cu content in the soil for the lettuce plants was 80.00 mg kg^-1. A percolation study showed that the Cu contents were larger for the first 20 cm of depth, indicating that the metal was not transported down the soil profile. The Cu content of different fractions declined in an order residual > amorphous iron oxide > crystalline iron oxide > organic matter > exchangeable, regardless of treatment performed. Additionally, the Cu contents added from treatments were determined mainly in amorphous iron oxide fraction.     

黄花甸子流域土壤全氮含量空间分布及其影响因素

以内蒙古赤峰市敖汉旗黄花甸子流域为研究对象,运用地统计学方法分析流域内土壤全氮含量的空间分布特征及地形因子和土地利用方式对其的影响.结果表明:流域内各土层土壤全氮含量均呈岛状分布,其高值区均集中分布在流域西北部,呈现出明显肥岛状;低值区主要在流域南部连片分布.全氮主要富集在表层土壤中,且随着土壤深度的增加而降低.土壤全氮含量随着海拔的增加均呈现出先增高后降低的趋势;随坡度的增加而显著降低;不同坡向上表现为阴坡＞半阴坡＞半阳坡＞阳坡.不同土地利用方式下土壤全氮平均含量由高到低表现为农地＞林地＞草地.     

Role of HERP and a HERP-related Protein in HRD1-dependent Protein Degradation at the Endoplasmic Reticulum

Misfolded proteins of the endoplasmic reticulum (ER) are retrotranslocated to the cytosol and degraded by the proteasome via a process termed ER-associated degradation (ERAD). The precise mechanism of retrotranslocation is unclear. Here, we use several lumenal ERAD substrates targeted for degradation by the ubiquitin ligase HRD1 including SHH (sonic hedgehog) and NHK (null Hong Kong α1-antitrypsin) to study the geometry, organization, and regulation of the HRD1-containing ERAD machinery. We report a new HRD1-associated membrane protein named HERP2, which is homologous to the previously identified HRD1 partner HERP1. Despite sequence homology, HERP2 is constitutively expressed in cells, whereas HERP1 is highly induced by ER stress. We find that these proteins are required for efficient degradation of both glycosylated and nonglycosylated SHH proteins as well as NHK. In cells depleted of HERPs, SHH proteins are largely trapped inside the ER with a fraction of the stabilized SHH protein bound to the HRD1-SEL1L ligase complex. Ubiquitination of SHH is significantly attenuated in the absence of HERPs, suggesting a defect in retrotranslocation. Both HERP proteins interact with HRD1 through a region located in the cytosol. However, unlike its homolog in Saccharomyces cerevisiae, HERPs do not regulate HRD1 stability or oligomerization status. Instead, they help recruit DERL2 to the HRD1-SEL1L complex. Additionally, the UBL domain of HERP1 also seems to have a function independent of DERL2 recruitment in ERAD. Our studies have revealed a critical scaffolding function for mammalian HERP proteins that is required for forming an active retrotranslocation complex containing HRD1, SEL1L, and DERL2.     

Sensitive bioassays for determining residues of sulfonylurea herbicides in soil and their availability to crop plants

Sulfonylurea herbicides are potent inhibitors of plant growth and are extremely active against a wide spectrum of weeds. They are used at very low rates (10–50 g ai/ha) and cause rapid inhibition of root and shoot growth of young plants. Routine chemical assays for detecting low levels of these compounds are difficult and there is need to develop sensitive bioassay methods for detecting their extremely low residue levels in the soil.This paper describes a simple pot bioassay method with a self watering system using turnip (Brassica rapa) seedlings as test plants for quantitative determination of sulfonylurea herbicides. Results are presented with six of these compounds whose activity was investigated in widely differing substrates. The potential availability to plants was calculated from the dose-response curves in different substrates. The dose-response relationship has been described by a specifically developed computer model. Details are also given of a direct seeded bioassay method with controlled watering system using several test species for detection of sulfonylurea herbicides. The potential uses and practical applications of both techniques are discussed.     

An Estimation Procedure for the Joint Distribution of Spatial Direction and Thickness of Flat Bodies Using Vertical Sections. Part II: An application in soil micromorphology

In soil micromorphology fissures are considered in vertical sections. To get information about the properties of the soil the joint distribution of spatial direction and width of these fissures is of interest. The fissures are mathematically generalized to flat bodies which are defined as stationary weighted surface processes with the weight “thickness”. In a typical point of the surface process suitable, joint parametric distributions of direction and thickness are assumed. The parameters have to be estimated from measurements on vertical sections which are taken from the soil. On these sections only a visible thickness and a visible angle can be observed. The joint distribution of these variables can be expressed by the joint distribution of spatial direction and thickness with the same parameters and in this indirect way the parameters can be estimated. The paper describes how to randomize the vertical section and how to measure the visible variables on the sections. The Chi-Square method is proposed for the parameter estimation. Further it is discussed how to derive good starting values for the numerical procedure. All this is demonstrated in a simulation study using the Bingham-Mardia distribution for the direction and the lognormal distribution for the thickness including a way to correlate the mean thickness and the direction. Finally an application in soil micromorphology is demonstrated for one soil horizon.     

Enhanced mineralization and denitrification as a result of heterogeneous distribution of clover residues in soil

Batch studies were conducted with Mn oxides (birnessite-hausmannite mixture, BHM) and samples of four soil series from the Mid-Atlantic region of the USA to determine effects of reducing organic acids, similar to those found in the rhizosphere, on the SeO₃/SeO₄ distribution. Jackland (Typic Hapludalf), Myersville (Ultic Hapludalf), Christiana (Aeric Paleaquult), and Evesboro (Typic Quartizipsamment) A and B horizon soil samples with and without prior Mn oxide reduction were incubated aerobically for 10 d with 0.1 mmol kg^-1 SeO₃ and 0 or 25 mmol kg^-1 of ascorbic acid, gallic acid, oxalic acid, or citric acid. Selenite was also added to BHM (10 mmol kg^-1) with 0 or 0.1 mmol kg^-1 ascorbic acid. The availability of Se for plant uptake as a result of root-soil interactions was examined using growth chamber studies with barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) seedlings grown in 150-mL cone-shaped containers to maximize root-soil surface interactions and to create rhizosphere soil throughout the root zone. In the BHM system ascorbic acid increased oxidation of SeO₃ to SeO₄ to 33% of added SeO₃. In the presence of ascorbic and gallic acids and Mn oxides, oxidation of SeO₃ to SeO₄ occurred in the B horizons of all the soils and in the A horizons of Jackland and Myersville soils. Removal of Mn oxides decreased the oxidation in some samples. Wheat and barley plants were able to accumulate up to 20 mol Se kg^-1 from the Jackland soil when soluble Se was not measurable. The root-soil interactions in the Jackland soil with barley and wheat provided the plant with Se from insoluble sources. The results also indicate that Mn oxides coming in contact with reducing root exudates have a greater ability to oxidize SeO₃ to SeO₄. Thus, rhizosphere processes play an important role in the availability of Se for plant uptake.Maryland Agricultural Experiment Station Scientific Article A 6381.Maryland Agricultural Experiment Station Scientific Article A 6381.