The metabolism of 14C-labeled fatty acids and triacylglycerols was followed in intact germinating oil palm seedlings as well as in tissue slices. In the germinating seedling, the shoot contained...Full Text Available
The dominant shrubs were sagebrush and spiny hopsage; the herbs were dominated by cheatgrass and Sandberg bluegrass. Spiny hopsage appeared to be vulnerable to burning and also to damage by off-road vehicular traffic. It appears to have little or no ability to reproduce through seedlings; once the existing plants are killed they are not likely to be replaced, even if seed-producing plants are nearby. The only pure stand of spiny hopsage known to exist on the Hanford Site is on and near study plot 2H. Sagebrush, like spiny hopsage, is killed by burning and by heavy vehicles. Sagebrush is capable of reproducing via seeds, indicating that it is an inherently aggressive species with a capacity to reestablish itself if parent plants are in the vicinity to act as seed sources. Alien, annual plants, especially cheatgrass, were a major contributor to the herbaceous canopy cover in plots 3S, 4S, and 5S. However, native perennial grasses, especially ...
1. γ-Hexachlorocyclohexane, γ-pentachlorocyclohexene and δ-pentachlorocyclohexene were converted by houseflies and grass grubs into metabolites that had chromatographic properties...Full Text Available
Oryza sativa or Asian cultivated rice is one of the major cereal grass species domesticated for human food use during the Neolithic. Domestication of this species from the wild grass...Full Text Available
Labelling of "1"4C-M-ISP and its absorption, translocation and distribution in peanut and soybean seedling were studied. The results of experiments showed that the radioactive substance could be translocated in xylem and phloem of two kinds of plants. The root of peanut seedling absorbed "1"4C-M-ISP from the nutrient solution more strong than the root of soybean seedling did. After leaf treatment with "1"4C-M-ISP, the soybean seedling absorbed more radioactive substance than peanut seedling did. But the translocation's speed of radioactive substance in pnloem of two kinds of plants were similar.
Background and AimsIn spatially heterogeneous environments, a trade-off between seedling survival and relative growth rate may promote the coexistence of plant species. In temperate...Full Text Available
In germinating oil palm (Elaeis guineensis var D × P) seedling, an active lipase was present in the shoot but absent from both the kernel and the haustorium. It has an optimum...Full Text Available
Studies were conducted with 9 to 12 day-old soybean (Glycine max [L.] Merr. cv. Williams) seedlings to determine the contribution of roots to whole plant NO3−...Full Text Available
The speed of ethylene-induced leaf abscission in cotton (Gossypium hirsutum L. cv LG-102) seedlings is dependent on leaf position (i.e. physiological age). Fumigation...Full Text Available
The electrical parameters that affect young seedling growth were investigated. Voltages ranging from 5 to 40 volts were applied longitudinally along the mesocotyl region of 4-day old Zea mays...Full Text Available
Plants respond to a large variety of environmental signals, including changes in the gravity vector (gravistimulation). In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation...Full Text Available
Germinating seedlings of Catharanthus roseus produce monoterpenoid indole alkaloids as a result of a transient increase of tryptophan decarboxylase (TDC) activity. The influence of...Full Text Available
Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport...Full Text Available
Analysis of data on seedling traits from 20 diverse genotypes revealed significant differences fro most of the seedling traits. Significant estimates of broad-sense heritability were observed for VI, ERI, FRTW, DRTW and R/S ratio. Genetic advance was maximum for VI,ERI and E%. The correlation of VI with ERI and R/S ratio was negative and significant, whereas it was positive and significant with E%, FSHW and DSHW. Characterization of the sorghum genotypes according to Anderson's Metro glyph Statistics revealed five different groups for seedling trails. (authors)
Vermicompost preparations are increasingly used in agricultural practice. There is a possibility, that crop plants are sensitive to negative effect of vermicompost at early stages of development. The aim of the present study was to test the effects of vermicompost on seed germination and seedling growth of different vegetable crop species. Vermicompost substitution inhibited seed germination and seedling growth with almost linear decrease of growth with increasing concentration of vermicopost in the substrate. However, both leaf chlorophyll content and photochemical activity of photosynthesis increased in all crop species with the exception of pea seedlings. Vermicompost extract as a watering solution showed positive effect on growth of bean and pea seedlings. Germination response of vermi...
ABSTRACT Drought is an important seedling mortality agent in dry and moist tropical forests, and more severe and frequent droughts are predicted in the future. The effect of drought on leaf gas exchange and seedling survival was tested in a dry-down experiment with four tree species from dry and moist forests in Bolivia. Seedlings were droughted and wilting stage and gas exchange were monitored. Drought led to a gradual reduction of photosynthesis and stomatal conductance over time, whereas respiration and photosynthetic water-use efficiency initially increased with drought and then declined. Seedlings gradually went through the different wilting stages, until they eventually died, but the trajectory differed for the four species. The strong relationship between wilting stage and photosynt...
In order to quantify the biomass burning emissions, the main atmospheric pollution source of tropical and subtropical regions, we carried out the analysis of ashes that are also formed during these fires. To this end, we developed analytical methods to characterize the composition of savannah grass burning ashes by using X-ray fluorescence for mineral elements and microanalysis for C, H, O and N. Samples used in this work have been collected during laboratory combustion experiments, with chemically well-defined natural savannah grasses from Ivory Coasts and South Africa. The reproducibility and efficiency of different developed procedures have been studies. The analytical relative precision is generally better than 5%. This development has allowed to establish, for the first time, the global mass balance of ashes resulting from savannah grass burning. (authors). 16 refs., 3 figs., 8 tabs.
The starting material for two certified and one candidate reference material was obtained from dried grass specially cultivated on a selected and well prepared soil. The Community Bureau of Reference (BCR) of the Commission of the European Communities produced two certified reference materials (CRM`s) from this dried grass: a rye grass material (CRM 281) certified in 1988 for the quality control of trace and toxic element analyses and a hay powder material (CRM 129) certified in 1989 for monitoring trace and minor elements. A fraction of the dried grass was used in 1993 for the preparation of a hay powder with a particle size of < 63 {mu}m using newly developed grinding techniques. This paper compares the production methods of these three materials and the obtained particle size distribution of the powders. The analytical evaluation of these production methods was carried out by solid sampling Zeeman ...
DescriptionInefficient utilisation of dietary nitrogen (N) by animals results in the excretion of N in varying forms, with adverse environmental consequences. Grass silage is a major component of the diet of ruminant livestock in the UK, but the protein in silage is very highly degraded as a result of the ensilage process. This results in poor capture of the silage N by rumen microbes leading to overall poor utilisation for the synthesis of milk or meat. As a result, significant quantities of dietary N are [continued...
The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte...Full Text Available
Seed priming technique has been known to improve germination and seedling emergence under different environment stresses. The objective of this study was to evaluate the effectiveness of seed priming in improving the seed germination and seedling vigor of Agropyron elongatum and Bromus inermis in response to five concentrations of the allelopathic extract of Thymus kotschyanus (0, 5%, 25%, 50% and 75%) under laboratory conditions. Pretreatments included gibberellic acid (250, 500 and 1000 ppm), potassium nitrate (0.1%, 0.2% and 0.3%) and salicylic acid (100, 200 and 300 mg/L). This experiment was carried out as a factorial experiment based on a completely randomized design with four replications. The results showed that seed germination, germination speed and seedling vigor were significan...
Old World Bluestems (OWB), introduced from Europe and Asia in the 1920s, recently have begun to raise concerns in the Great Plains. Despite suggestion in the late 1950s that OWB were weedy and negatively impacted biological diversity, they were widely introduced throughout the Great Plains for agricultural purposes. Anecdotal evidence suggests that OWB exhibit invasive characteristics that promote competitive exclusion of native species. The objective of our study was to quantify the competitive abilities of two OWB species (Caucasian bluestem; Bothriochloa bladhii (Retz.) S.T. Blake (=?Bothriochloa caucasica (Trin.) C.E. Hubb.) and yellow bluestem; Bothriochloa ischaemum (L.) Keng) with three native grass species (big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium s...
Native plant individuals often persist within communities dominated by exotics but the influence of this exposure on native populations is poorly understood. Selection for traits contributing to competitive ability may lead to native plant populations that are more tolerant of the presence of exotic invaders. In this way, long-term coexistence with an exotic may confer competitive advantages to remnant (experienced) native populations and be potentially beneficial to restoration. In past studies we have documented genetic differentiation within native grass populations exposed to the exotic invader Russian knapweed (Acroptilon repens). Here, we examine populations of a cool-season grass, needle-and-thread (Hesperostipa comata [Trin. & Rupr.]) and a warm season, alkali sacaton (Sporobolus a...
Plantago ovata Forsk - an economically important medicinal plant - was analyzed for trace elements and chlorophyll in a study of the effects of gamma radiation on physiological responses of the seedlings. Proton-induced X-ray emission (PIXE) technique was used to quantify trace elements in unirradiated and gamma-irradiated plants at the seedling stage. The experiments revealed radiation-induced changes in the trace element and chlorophyll concentrations.
Juvenile trees of kalmia derived from shoot tip culture, and seedlings of kobus were irradiated with #gamma#-rays. In kalmia, two mutation lines were obtained which had narrowlong leaves. In kobus two mutation lines were obtained. One mutation line has flowers with 7 to 13 petals. Another mutation line has yellow-green variegated leaves. (author).
Roots of maize (Zea mays L.) seedlings continue to grow at low water potentials that cause complete inhibition of shoot growth. In this study, we have investigated the role of abscisic...Full Text Available
Methods and materials employed by NCL to reclaim treatment of overburden dumps in opencast projects are described. These involve controlling slope stability and erosion (for example by covering with geosynthetic composites or jute/coir mat) and installing a drainage system before planting trees, shrubs and grass. 1 photo.
The global problem concerning contamination of the environment because of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contribute...
A commercial blend of essential oil (EO) compounds was added to a grass, maize silage, and concentrate diet fed to dairy cattle in order to determine their influence on protein metabolism by ruminal...Full Text Available
This paper describes the development of an interactive internet-based cost-estimating tool for commonly used urban storm runoff best management practices (BMP), including: retention and detention ponds, grassed swales, and constructed wetlands. The paper presents the cost data, c...
Mung bean seedlings inoculated with Enterobacter asburiae PSI3, a gluconic acid-producing rhizosphere isolate, enhanced plant growth in the presence of phytotoxic levels of Cd2+ in gnotobiotic pot experiments as compared to the uninoculated Cd-treated plants. Addition of organic acids to Cd-stressed seedlings promoted root elongation. Hematoxylin competition assays showed that organic acids could displace Cd2+ from the Cd2+: hematoxylin complex in the same order of effectiveness as was found for restoration of root net elongation viz. oxalate?>?malate?>?succinate while gluconate was effective at higher concentrations. Root associated Cd2+, assessed by hematoxylin staining of roots was found to be reduced when roots were treated with organic acid. Cd stress increased antioxidant enzymes suc...
During germination and early growth of castor bean (Ricinus communis), all cellular constituents of the endosperm are eventually transferred to the growing embryo. The present results...Full Text Available
When the detached first leaves of green or etiolated oat (Avena sativa cv. Victory) seedlings senesce in the dark, their oxygen consumption shows a large increase, beginning after 24...Full Text Available
Cytosol proteins prepared from castor bean endosperm (4-day-old) seedlings stimulate the exchange of [3H]phosphatidylethanolamine between liposomes and mitochondria. The acceleration of the...Full Text Available
The establishment of the primary meristems through proliferation after germination is essential for plant post-embryonic development. Cytokinins have long been considered a key regulator of...Full Text Available
The stability of catalase, fumarase, and isocitrate lyase from deliberately broken organelles in crude extracts from endosperm tissue of castor bean seedlings has been examined. These enzymes are relatively...Full Text Available
Brief exposures to red light induce far red-reversible changes of 5 to 10 millivolts magnitude in the upper 1 centimeter of etiolated Avena coleoptiles. The changes begin within 15...Full Text Available
Nitrogenase-dependent acetylene reduction, nodule function, and nodule regrowth were studied during vegetative regrowth of harvested (detopped) alfalfa (Medicago sativa L.) seedlings...Full Text Available
Protoplasts were isolated from the leaves of nitrate-cultured wheat (Triticum aestivum L. var. Frederick) seedlings. When incubated in the dark, protoplasts accumulated nitrite under...Full Text Available
The inhibitory effects of indole-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) on elongation growth of pea (Pisum sativum L.) seedling roots were investigated...Full Text Available
A cell-free system which catalyzes the biosynthesis of terpene hydrocarbons when supplemented with mevalonate, Mn2+, and ATP was prepared from the scutellum-embryonic axis region of maize...Full Text Available
Nitrate reduction was studied as a function of carbohydrate concentration in detached primary leaves of barley (Hordeum vulgare L. cv Numar) seedlings under aerobic conditions in light...Full Text Available
The biological and radiobiological peculiarities of seeds and seedlings of the Rumex confertus and Lupinus polycolor plants, which grown during several generations in plots with different level of radionuclide pollution of the Chernobyl exclusive zone have been investigated.
Malate synthase (EC 4.1.3.2), an enzyme unique to the glyoxylate cycle, was purified to homogeneity from cotyledons of 72-hours, darkgrown cotton (Gossypium hirsutum L.) seedlings....Full Text Available
Partial digestion of polygalacturonic acid with polygalacturonase isolated from Rhizopus stolonifer produces a mixture of α-1,4-d-galacturonide oligomers which act...Full Text Available
Two nitrate reductase (NR) mutants were selected for low nitrate reductase (LNR) activity by in vivo NR microassays of M2seedlings derived from nitrosomethylurea-mutagenized...Full Text Available
The relative roles of de novo biosynthesis of indoleacetic acid (IAA) and IAA conjugates stored in mature seeds (Phaseolus vulgaris L.) in supplying auxin to germinating bean seedlings...Full Text Available
Low concentrations of sugars altered the sensitivity of seed germination to inhibition by exogenous abscisic acid (ABA). Germination of wild-type and ABA-insensitive (abi) Arabidopsis...Full Text Available
Micropropagation methods are described for the production of clonal lines from Eucalyptus marginata (jarrah) seedlings. Nodal explants from mature trees can also yield shoot cultures, but a high frequency of contamination occurs among such explants. Uncontaminated callus cultures can be produced from mature trees by culturing stamen filaments and shoots can subsequently be regenerated from this callus. The rooting percentage of shoot cultures from either nodes or stamen callus of mature trees is low compared with that from seedling explants. Considerable variation was observed between trees in the ability of stamen callus to regenerate shoots and in the frequency of rooting. (Refs. 27)
Biomass and nutrient dynamics of black spruce seedlings during the hardening phase of the greenhouse rotation were examined after four pre-hardening fertilization regimes - conventional, constant-rate loading, exponential loading, and high exponential loading (delivering respectively 15, 40, 40 and 60 mg N seedling{sup -1}) - in order to assess nutrient dilution and steady-state nutrition. Although height growth of seedlings had virtually ceased during hardening, shoot biomass increased 99-142% and root biomass increased five- to tenfold depending on treatment. The biomass increase compromised steady-state nutrient status by diluting internal nutrient pools as nutrient supply was unable to keep up with growth. Soil nutrient levels were rapidly depleted during this period because of plant uptake and lack of fertilizer supplementation. Pre-hardening nutrient loading partly countered and delayed dilution effects, especially ...
This study is part of a greater project from IPT (Sao Paulo's Institute of Technology), which foresaw an energetic use for elephant-grass (Pennisetum purpureum). Biomass gasification is an sustainable option for energy supply, which presents low pollutants emission rate and allows - through the global cycle of growing and consumption of feedstock (vegetables), a balance between consumption and production of carbonic gas, preventing an increase of the carbonic gas levels in the atmosphere. A gasifier was built with internal diameter of 400 mm and total height of 4600 mm . The equipment was tested for gasification of elephant-grass (Pennisetum purpureum) at a 100 kg/h rate. The equipment was tested and some constructive faults were detected. In the countryside, this biomass is commonly used for cattle feeding It was evaluated an adequate diesel-electric-generator. to work at hybrid regime, using 70% biomass gas and 30% diesel. With the ...
This pilot project was carried out for the purpose of testing methods for active biological monitoring. It covered a period of three years (until September 1994), including two years of exposure. The measurements served to determine pollutant levels in plants used as animal fodder and dust-borne heavy metal concentrations in different sites and, on this basis, to obtain indirect information on human exposure. Among others, the pilot project investigated the suitability of Italian rye-grass as a biological indicator for aluminium, arsenic, cadmium, cobalt, chromium, copper, iron, mercury, magnesium, manganese, nickel, lead, platinum, antimony, titanium, and zinc. (orig./GL).
Summary 1.-Plant-plant interactions fluctuate between competition and facilitation depending upon ecological conditions and species traits. Facilitative interactions are expected to increase in frequency via associational defences with increasing consumer pressure. The ability of species to cope with competition and/or ecological stressors may alter the outcome of plant-plant interactions. 2.-We conducted a transplant experiment to determine if native and non-native grasses and forbs respond similarly to interactions with Juncus effusus L., an unpalatable benefactor species, along a grazing intensity gradient in two contrasting pasture types: intensively managed and semi-natural. We expected competitive taller, erect species (grasses) and non-natives to obtain stronger facilitative effects...
Bothriochloa ischaemum L. and Lespedeza davurica (Laxm.) Schindl. are two co-dominant species of great importance in reducing soil and water loss and maintaining the distinctive natural scenery of the semiarid Loess Plateau of China. Our aim was to determine the growth and interspecific competition between these species under water stress to facilitate the prediction of community succession and guide the selection of appropriate methods of conservation and use in the area. A pot experiment was designed to investigate the effects of water stress and competition on biomass production and allocation, relative competitive ability and water use efficiency of the two species. Bothriochloa ischaemum (a C4 perennial herbaceous grass) was planted in the same pot with L. davurica (a C3 perennial leg...
The inhibition of DDT [1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane] dehydrochlorinase and glutathione S-aryltransferase by diphenylmethane and triphenylmethane...Full Text Available
... It is well camouflaged and each individual has unique back pattern markings. It eats mainly spiders and insects. The Eastern Lined Earless Dragon is a small dragon lizard measuring up to 21cm in length. It is well camouflaged and each individual has unique back ... It is well camouflaged and each individual has unique back pattern markings. It eats mainly spiders and insects. It lives in and around grass tussocks as well as small holes in the ground that are also used by invertebrates such as wolf spiders and crickets....
Studies of flower development in core eudicot species have established a central role for B class MADS-box genes in specifying petal and stamen identities. Similarly in maize and rice, B class genes...Full Text Available
This experiment was undertaken to screen the acaricidal effects of herb essential oils (pennyroyal, ylang ylang, citronella, lemon grass, tea tree, and rosemary) at different doses (0.1, 0.05, 0.025,...Full Text Available
Nitric oxide (NO) and related molecules such as peroxynitrite, S-nitrosoglutathione (GSNO), and nitrotyrosine, among others, are involved in physiological processes as well in the mechanisms of response to stress conditions. In sunflower seedlings exposed to five different adverse environmental conditions (low temperature, mechanical wounding, high light intensity, continuous light, and continuous darkness), key components of the metabolism of reactive nitrogen species (RNS) and reactive oxygen species (ROS), including the enzyme activities L-arginine-dependent nitric oxide synthase (NOS), S-nitrosogluthathione reductase (GSNOR), nitrate reductase (NR), catalase, and superoxide dismutase, the content of lipid hydroperoxide, hydrogen peroxide, S-nitrosothiols (SNOs), the cellular level of N...
Basal stem rot of oil palm (OP) by Ganoderma boninense is of major economic concern and it is the predominant disease of OP in SE Asia. Also, other plantation crops are affected by Ganoderma. The early detection of symptoms is crucial for control, although effective methods remain elusive. Ergosterol is the principal sterol of fungi and plays an essential role in the cell membrane and other cellular constituents. The analysis of ergosterol is useful for fungal detection in solid plant substrates. The present report compares ergosterol concentration in sound and decayed OP seedlings and mature plants using HPLC with diode array detection. The disease of OP requires to be considered as a white rot process where fungal biomass will increase from a low to high level as the infection progresses...
Endophytes are microorganisms that live within healthy plant tissues, and include fungi and bacteria. They can be mutualists, comensals or even latent pathogens. Presence of these endosymbionts may affect host physiology, for example by consuming products of photosynthesis (endophytes are heterotrophs) or producing toxic metabolites. In this work two fungicides were used to eliminate fungal endophytes from seedlings of guarea guidonia. light saturated photosynthesis (Amax) was measured in endophytefree plants and compared with control plants. Each fungicide killed different fungal endosymbionts. phomopsis was more susceptible to benomyl while colletotrichum was more susceptible to propiconazole. Although suggestive, values of Amax were not significantly different for each treatment compared with control plants. No prediction can be made at this point about the final outcome of a given plantendophytic fungi interaction
As the main forestry species in the Canary Islands (Spain), Pinus canariensis is frequently used in afforestation programs. Several nursery techniques are commonly employed to modify its morphology and physiology with the aim of improving post-planting survival and growth. In this work, we studied how fertilization and light regime treatments applied during the nursery period modify biomass allocation patterns and produce effects in gas exchange and root hydraulic conductance. Seedlings were grown for a 6-month period in the nursery under two light regimes (full sunlight and 40% PAR reduction), and three fertilization levels were applied in each light regime. Morphology, biomass allocation patterns, leaf gas exchange and hydraulic conductance of the whole root system were evaluated. Fertil...
If 4-day-old dark-grown zucchini squash seedlings (Cucurbita pepo L. cv. Black Beauty) are exposed briefly to red light, subsequent cell fractionation yields about 40% of the total...Full Text Available
The variation of indole-3-acetic acid (IAA) transport along Lupinus albus L. hypocotyls was studied using decapitated seedlings and excised sections. To confirm that the mobile species...Full Text Available
Rice (Oryza sativa) seed storage proteins (SSPs) are synthesized and deposited in storage organelles in the endosperm during seed maturation as a nitrogen source for germinating seedlings....Full Text Available
Detached first leaves of 3-day-old corn seedlings (Zea mays L. W64AxW183E) were incubated with nitrate in air or 100% O2 in the light. Nitrate accumulation in the leaves...Full Text Available
Maleic hydrazide (MH) is taken up by corn and pea seedling roots and bound to some material which is insoluble in 80% ethanol or 5% trichloroacetic acid. 14C-MH is stable metabolically; chromatography...Full Text Available
Two nitrate reductase deficient mutants of soybean (Glycine max [L.] Merr. cv Bragg) were isolated from approximately 10,000 M2seedlings, using a direct enzymic assay in...Full Text Available
Primary leaves of 7- to 9-day-old etiolated seedlings of Phaseolus vulgaris L. var. Red Kidney infiltrated in darkness with aqueous solutions of α, α′-dipyridyl,...Full Text Available
sigma-Aminolevulinate dehydratase has been found to be activated in vitro by dithiotreitol and factors isolated from radish cotyledons grown under continuous far-red light. Cross experiments, between fructose 1-6 bisphosphatase system, and sigma-aminolevulinate dehydratase, show that these factors are functionally identical to thioredoxin f.
Six genotypes of winter wheat (Triticum aestivum L.) differing in grain protein concentration were grown on a nutrient solution containing low concentrations of NO3−...Full Text Available
The effect of ionizing radiation (2, 5, and 10 KGy of gamma rays) on muscle ultrastructure of grass shrimps (Penaeus monodon Fabricius) tails at ambient or frozen (-18{sup 0}C) temperature was investigated by transmission electron microscopy (TEM). No significant change was found in muscle ultrastructure of shrimp meat irradiated at doses of 2 or 5 KGy and then stored at 4{sup 0}C for 0 and 8 days. However, in shrimps which were irradiated at ambient temperature at a dose of 10 KGy, the margin of A-band of the myofibrils in longitudinal sections exhibited an irregular zig-zag pattern. In cross section some myosin filaments in the A-band regions were missing. A possible interpretation of these results would be that 10 KGy gamma irradiation dose at ambient temperature depolymerized myosin in the A-band from the tail of thick filament. Actin damage was also observed in some cross sections. Irradiation damage of sarcoplasmic membranes appeared in the specimens ...
The effect of ionizing radiation (2, 5, and 10 KGy of gamma rays) on muscle ultrastructure of grass shrimps (Penaeus monodon Fabricius) tails at ambient or frozen (-18"0C) temperature was investigated by transmission electron microscopy (TEM). No significant change was found in muscle ultrastructure of shrimp meat irradiated at doses of 2 or 5 KGy and then stored at 4"0C for 0 and 8 days. However, in shrimps which were irradiated at ambient temperature at a dose of 10 KGy, the margin of A-band of the myofibrils in longitudinal sections exhibited an irregular zig-zag pattern. In cross section some myosin filaments in the A-band regions were missing. A possible interpretation of these results would be that 10 KGy gamma irradiation dose at ambient temperature depolymerized myosin in the A-band from the tail of thick filament. Actin damage was also observed in some cross sections. Irradiation damage of sarcoplasmic membranes appeared in the specimens irradiated at a ...
Six species having characteristics of plants with the C(4) dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon L. (Bermuda grass), Kyllinga brevifolia Rottb., Amaranthus tricolor L. cv. Early splendour, Kochia childsii Hort., and Portulaca grandiflora Hook (rose moss), responded decisively to 0.1 milliequivalent per liter NaCl supplied to their culture solutions initially containing less than 0.08 microequivalent per liter Na. Chlorosis and necrosis occurred in leaves of plants not receiving sodium. Portulaca failed to set flower in the sodium-deficient cultures. Under similar conditions Poa pratensis L. (Kentucky blue grass) having characteristics of the C(3) photosynthetic pathway made normal growth and did not respond to the addition of sodium. It is concluded from these results and previously reported work that sodium is generally essential for species having the C(4) pathway but not ...
Six species having characteristics of plants with the C4 dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon L. (Bermuda grass), Kyllinga brevifolia Rottb., Amaranthus tricolor L. cv. Early splendour, Kochia childsii Hort., and Portulaca grandiflora Hook (rose moss), responded decisively to 0.1 milliequivalent per liter NaCl supplied to their culture solutions initially containing less than 0.08 microequivalent per liter Na. Chlorosis and necrosis occurred in leaves of plants not receiving sodium. Portulaca failed to set flower in the sodium-deficient cultures. Under similar conditions Poa pratensis L. (Kentucky blue grass) having characteristics of the C3 photosynthetic pathway made normal growth and did not respond to the addition of sodium. It is concluded from these results and previously reported work that sodium is generally essential for species having the C4 pathway but not for ...
The economic attractiveness and negative environmental impact of nitrogen (N) fertilization in pastures depend on the N use efficiency in the soil-plant system. However, the recovery of urea-{sup 15}N by Panicum maximum cv. Tanzania pastures, one of the most widely used forage species in intensified pastoral systems, is still unknown. This experiment was conducted in a randomized complete block design with four treatments (0, 40, 80 and 120 kg ha-1 of N-urea) and three replications, to determine the recovery of {sup 15}N urea by Tanzania grass. Forage production, total N content and N yield were not affected by fertilization (p > 0.05), reflecting the high losses of applied N under the experimental conditions. The recovery of {sup 15}N urea (% of applied N) in forage and roots was not affected by fertilization levels (p > 0.05), but decreased exponentially in the soil and soil-plant system (p < 0.05) with increasing urea doses. The amount of ...
The economic attractiveness and negative environmental impact of nitrogen (N) fertilization in pastures depend on the N use efficiency in the soil-plant system. However, the recovery of urea-"1"5N by Panicum maximum cv. Tanzania pastures, one of the most widely used forage species in intensified pastoral systems, is still unknown. This experiment was conducted in a randomized complete block design with four treatments (0, 40, 80 and 120 kg ha-1 of N-urea) and three replications, to determine the recovery of "1"5N urea by Tanzania grass. Forage production, total N content and N yield were not affected by fertilization (p > 0.05), reflecting the high losses of applied N under the experimental conditions. The recovery of "1"5N urea (% of applied N) in forage and roots was not affected by fertilization levels (p > 0.05), but decreased exponentially in the soil and soil-plant system (p < 0.05) with increasing urea doses. The amount of "1"5N (kg ha"-"1) in ...
The experiment was conducted at the laboratory of Experimental Station of Instituto Agronomico de Campinas, in Piracicaba, SP, BR. The elephant-grass (Penissetum purpureum Schum) cv Guacu, with 6 months of development was chopped in a forage chopper regulated to cut biomass in pieces of 5 mm. 500 grams of chopped biomass was pressed in a hydraulic presser regulated for 60, 120, 180, 240 and 300 kg/cm{sup 2}. For the pressure of 60, 120, 180 and 240 kg/cm{sup 2} the presser was used in manual module, while, for the pressure of 300 kg/cm{sup 2} it was operated in the automatic module. The experiment was executed in randomized block design with 4 repetitions. When the pressure of 300 kg/cm{sup 2} was used it was extracted 21.78 % of the moisture of biomass, while the nitrogen percentage was little altered by press. (author)
Increases in atmospheric CO[sub 2] are predicted to cause an increase in the C:N ratio of plant substrates entering the soil organic matter pool. We experimentally increased soil C:N ratios by adding 40 g C/m[sup 2] as sucrose (metabolic C) or cellulose (structural C) in short-, mid-, and tall-grass plots in the Serengeti Ecosystem, and measured plant productivity, plant nutrient uptake rates, and mineralization rates. Experimental treatments also included fencing to exclude grazing and additions of 40 g N/m[sup 2] as urea to simulate a urine hit from an average-sized ungulate. Productivity was only 60% of controls in C-addition plots, and was similar for sucrose and cellulose. However, this response was not observed in the short-grass site, an area of relatively low rainfall and high fertility. These results support the role of a plant-microbe negative feedback mechanism on plant growth in which increased C to microbes results in increased ...
The results are presented of a study in radioactivity of forage (grass, alfalfa, clover), cereals (wheat, oats, rye, barley) and different agriculture products (fodder beet, sugar beet, leguminous plants, poppy, tobacco, maize, potatoes). Total beta activity, "4"0K, "9"0Sr and "1"3"7Cs activities were studied for the period 1962 to 1975 in selected localities in Slovakia. The highest values of "9"0Sr and "1"3"7Cs were measured in 1963, the lowest levels of "9"0Sr in 1975 while the lowest levels of "1"3"7Cs in 1973. (B.S.).
Florida posseses climatic, land, and water resources favorable for abundant biomass production. Therefore, a statewide program has been initiated to determine adapted species for the available array of production sites. Plant resources under investigation include woody, aquatic, grasses, hydrocarbon, and root crop species. The goal is to produce a continuous stream of biomass for the various biofuel conversion options. Preliminary yields from energy cropping experiments range from about 10 to nearly 90 metric tons per hectare per year, depending on the crop and the production systems employed. (Refs. 15).
Florida imports about 85% of its energy needs. Among the renewable energy sources available, biomass appears promising in Florida because of a favourable environment for production and the available methods to convert biomass to energy. Optimal production of biomass requires the identification and management of high yielding persistent perennial cultivars. Elephantgrass (Pennisetum purpureum Schum.) and energycane (Saccharum spontaneum L.) are two tall grasses that meet these requirements. To optimize the supply of convertible biomass, suitable methods of harvesting the crop must be available. The purpose of this research was to study the feasibility and energetics of harvesting, drying and baling tall grasses with conventional farm machinery. A Mathews rotary scythe and a New Holland 849 Auto Wrap large round baler were determined to provide a practical harvesting system for baled biomass averaging 15-27 Mg ha [sup -1]. This harvesting system ...
Dehydrins, a subfamily of group 2 LEA proteins, are intrinsically unstructured plant proteins that accumulate in the late stages of seed development and in vegetative tissues subjected to water deficit, salinity, low temperature, or abscisic acid treatment. In this study, we isolated and characterized ZmDHN2b, a maize dehydrin gene. The genomic organization of the ZmDHN2b gene and its expression in maize seedlings were analyzed. To investigate the function of ZmDHN2b, we generated transgenic tobacco plants constitutively overexpressing ZmDHN2b. Ectopic expression of ZmDHN2b in tobacco accelerated seed germination and seedling growth at 15?C. Furthermore, ZmDHN2b-overexpressing lines had lower levels of cold-induced malondialdehyde and less electrolyte leakage than wild-type tobacco at 4?C....
This peer-reviewed article from Bioscience journal is about restoring the Truckee river.Throughout the 20th century, the Truckee River that flows from Lake Tahoe into the Nevada desert was progressively dammed and dewatered, which led to the collapse of its aquatic and riparian ecosystems. The federal designation of the endemic cui-ui sucker (Chasmistes cujus) as endangered prompted a restoration program in the 1980s aimed at increasing spring flows to permit fish spawning. These flows did promote cui-ui reproduction, as well as an unanticipated benefit, the extensive seedling recruitment of Fremont cottonwood (Populus fremontii) and sandbar willow (Salix exigua). Recruitment was scattered in 1983 but extensive in 1987, when the hydrograph satisfied the riparian recruitment box model that had been developed for other rivers. That model was subsequently applied to develop flow prescriptions that were implemented from 1995 through 2000 and enabled further ...
Brine from active oil wells seeped through the soil of a forested site in north-western Pennsylvania and killed all vegetation in its path, leaving the affected area unproductive and unsightly. After the brine source was eliminated, herbaceous plants, shrubs and forest tree seedlings became established and developed rapidly. Establishment began in the first year and by Year 4 the site had developed into a healthy young forest. Results show that Allegheny hardwood forest sites damaged by brine water will rapidly revegetate once the brine water discharge is stopped if there is a seed supply and if the area is fenced to exclude deer. 3 figs., 12 refs.
Methods are described for the production of callus and subsequent shoot and root induction and multiplication using stamen filaments, nodes of young stems of mature trees or cotyledon petioles. A high frequency of contamination occurred using nodal sections from mature trees, whereas up to 100% sterility was obtained with cotyledons and stamens. The rooting % of shoot cultures from nodes or stamen callus was low compared with that of shoots from seedling callus. Considerable variation was observed between clones from different trees in their ability to produce shoots and roots. 27 references
The twenty-three papers presented at this conference discussed requirements of land reclamation under the Federal surface mining regulations, evaluation techniques for assessing reclaimed land, spoil bank chemistry and its change with time, establishment techniques (vegetative propagation, containerized seedlings, nurse vegetation, nitrogen-fixing tree species, direct seeding, and general cultivation techniques), and results from early land reclamation trials. Twenty-two papers have been abstracted separately. 291 references, 16 figures, 80 tables.
Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.
A considerable time can elapse between initial selection of candidate plus trees and harvest of improved seed. The technique showing the greatest promise of shortening this interval is vegetative propagation. Stock plants are grown for two years from seed before the first propagation cycle begins and each plant can be bulked-up 300-500 times over two cycles. An initial stock of 2500 superior Sitka Spruce plants can be multiplied to yield between 300,000 and 750,000 rooted cuttings for forest use within four years from the start of propagation.
An increase in forest production will be necessary in the future when wood becomes a major renewable source of energy and chemicals along with its traditional role of fibre source. This increase could eventually by achieved be proper selection and breeding of trees. Clonal forestry by vegetative propagation of cuttings is becoming a viable alternative to a seedling-based forestry with many advantages, and cutting could be used to quickly propagate large numbers of clones of control-pollinated seedlings. Most forest trees are propagated sexually and seed orchards were started in the US and Canada in the last 40-50 years for breeding purposes. Forests could ultimately be established with improved seedlings instead of from seed with unknown genetic potential, or by natural regeneration. Micropropagation is the term used to refer to the propagation of plants raised by tissue culture methods rather than from seeds or cuttings. ...
Although low-energy ion radiation has been proven to have a wide range of biological effects and led to fruitful achievements as a new mutagenic source for genetic modification, there still exist some disputes about its mutagenic mechanisms because of its short-penetrating property. In present research, Arabidopsis thaliana transgenic for GUS recombination substrate was used to evaluate the genomic instability induced by irradiations of alpha particle (3.3MeV) and Low-energy-Argon ion (30 KeV). A pronounced effects of alpha particle irradiation to Arabidopsis thaliana seedlings and Argon ion irradiation to seeds on the somatic homologous recombination frequency (sHRF) were reported. The sHRFs increased 1.88-fold and 2.42-fold, respectively, which indicated that the short-penetrating radiation could effectively induce the plant genomic instability in either dry seeds or seedlings with active metabolism. The local alpha particle irradiation of ...
Measurement of fission and activation products in the soil or over a plane grass land of a nuclear power station environment is required to find out the long term changes. The inventory of radionuclides in the soil is routinely determined by soil sampling, processing and gamma spectrometry in the laboratory. The method although is proven and accurate is time consuming and largely dependent on homogenous distribution. Therefore, an alternative and rapid method of in-situ gamma spectrometry using portable devices was standardized to determine the concentration of radionuclides in soil, for regular environmental monitoring as well as during emergency condition. The paper presents the methodology, ready to use factors and compares the results of a few measurements made in the environment of Tarapur Atomic Power Station by both in-situ and laboratory methods. (author)
Invasive weeds have threatened the integrity of ecosystems throughout the world. They affect not only the species diversity of native areas but also their biological integrity. In India, a number of invasive exotic weeds have been reported but some viz. Parthenium hysterophorus, Lantana camara and Ageratum conyzoides, especially those from tropical America are troublesome and have caused adverse ecological, economic and social impact. These weeds can be seen growing in different landscapes but are luxuriantly localized in unattended forests and cultivated areas. Parthenium hysterophorus (Asteraceae, commonly known as congress grass) is perhaps the most troublesome and noxious weed of urban and rural India. Besides rapidly colonizing areas replacing the native vegetation, it is also known t...
We present an innovative approach to estimating residential irrigation water demand for a large metropolitan area using GIS data, weather station data, and a water budget modeling approach commonly used by plant scientists and landscape management professionals. An important question addressed by our study is how a growing urban forest affects the overall irrigation water demand of a semiarid metropolitan area. To estimate the amount of water required by residential landscaping, we consider water demand to be a function of the areal extent of residential landscaping (i.e. tree/shrub or turf grass), the water-loss rate for different landscaping types, the efficiency with which the landscape is irrigated, and local climatic factors (i.e. reference evapotranspiration and precipitation). We es...
Abstract: Decomposition and insect colonization of pig (Sus scrofa L.) carcasses were observed over a 42 day period inside and outside a house in a suburban region of Edmonton, Alberta. Three freshly killed pig carcasses were placed outdoors on grass and three carcasses were placed in separate rooms inside a house in a suburban residential area. The carcasses were examined and sampled regularly. Outside carcasses were colonized rapidly by Calliphora vicina (R D), Lucilia sericata (Meigen), Lucilia illustris (Meigen), Eucalliphora latifrons (Hough), Cynomya cadaverina (R D), Phormia regina (Meigen), and Protophormia terraenovae (R D). There was a delay of 5 days before inside carcasses were first colonized but all species except E. latifrons and L. illustris readily colonized at this time. ...
T-2 toxin, a highly toxic member of the type-A trichothecenes, is produced by various Fusarium moulds that can potentially affect human health. It is strongly cytotoxic for human hematopoietic progenitors. Alimentary toxic aleukia (ATA), a disease typically associated with human, is primarily induced by T-2 toxin. A comparison of the metabolism of T-2 toxin incubated with hepatocytes of rats, piglets, chickens, and the hepatic subcellular fractions (microsomes and cytosol) of piglets, chickens, rats, and carp (common carp and grass carp) was carried out. The activities of the recombinant pig CYP3A29 on the transformation of T-2 and HT-2 toxins were preliminary studied. Metabolites were identified by novel LC/MS-IT-TOF. Qualitative similarities and differences across the species were observ...
The aim of this research project, funded jointly by SILMU and by the Agricultural Research Centre of Finland, was to evaluate the possible effects of changes in climate and carbon dioxide concentration on the growth, development and yield of field crops and on crop pests and diseases in Finland. The study focused on two cereal crops (spring wheat and spring barley), a grass species (meadow fescue), some common pathogens of cereals and potato, insect pests of small fruits and nematode risk of potato and sugar beet. The results of this study indicate the following effects on crop production of the `best guess` climate change anticipated for Finland by 2050: A lengthening of the potential growing season of 3-5 weeks. A northward expansion of about 250-500 km in suitability for cereal production. Increased yields of adapted spring cereals. New, longer-season cultivars would benefit from both higher temperatures and elevated CO{sub 2}. Improved potential for the ...
The responses of ramets of hybrid poplar (Populus spp.) (HP) clones NE388 and NE359, and seedlings of red maple (Acer rubrum, L.) to ambient ozone (O_3) were studied during May-September of 2000 and 2001 under natural forest conditions and differing natural sunlight exposures (sun, partial shade and full shade). Ambient O_3 concentrations at the study site reached hourly peaks of 109 and 98 ppb in 2000 and 2001, respectively. Monthly 12-h average O_3 concentrations ranged from 32.3 to 52.9 ppb. Weekly 12-h average photosynthetically active radiation (PAR) within the sun, partial shade and full shade plots ranged from 200 to 750, 50 to 180, and 25 to 75 #mu#mol m"-"2 s"-"1, respectively. Ambient O_3 exposure induced visible foliar symptoms on HP NE388 and NE359 in both growing seasons, with more severe injury observed on NE388 than on NE359. Slight foliar symptoms were observed on red maple seedlings during the 2001growing season. Percentage of ...
To test the hypothesis that leaf level photosynthetic related traits might confer late successionals a competitive advantage over early successionals in low light growth conditions, steady photosynthetic assimilation and dynamic photosynthetic induction related traits were examined in low light grown seedlings with contrasting successional status. Compared with the early successionals, late successionals as a group significantly exhibited lower leaf gas exchange rates. While late successionals required a longer time to respond to simulated sunflecks, they had lower rates of induction losses after sunflecks. Such photosynthetic induction traits allowed late successionals to more effectively utilize subsequent sunflecks. It was observed that plants with lower gas exchange rates responded mor...
The cotton aphid, Aphis gossypii (Homoptera: Aphididae), is increasing in importance as a pest worldwide since the introduction of Bt-cotton, which controls lepidopteran but not homopteran pests. The chemical ecology of interactions between cotton, Gossypium hirsutum (Malvaceae), A. gossypii, and the predatory lacewing Chrysoperla lucasina (Neuroptera: Chrysopidae), was investigated with a view to providing new pest management strategies. Behavioral tests using a four-arm (Pettersson) olfactometer showed that alate A. gossypii spent significantly more time in the presence of odor from uninfested cotton seedlings compared to clean air, but significantly less time in the presence of odor from A. gossypii infested plants. A. gossypii also spent significantly more time in the presence of heads...
In tomato crop, the induction of resistance emerges as an important alternative for achieving the reduction of chemicals in disease control. This study aimed to evaluate the ability of 28 Trichoderma isolates to promote the growth of tomato seedlings and to induce systemic resistance (ISR) against Xanthomonas euvesicatoria and Alternaria solani, the causal agents of bacterial spot and early blight, respectively. Twelve isolates promoted the increase of plant dry matter mass (DMM) above 100%, showing the great potential of these strains. All isolates were able to colonize the root system of tomato plants. The plant growth-promoting isolates were further evaluated for potential elicitation of ISR. Treatment of the soil with all Trichoderma isolates provided protection in tomato plants from 2...
Lupinus albus L. plants were grown from seeds and irradiated at various stages of development with acute or chronic gamma rays. All plants were greenhouse grown (pre- and post-irradiation) and allowed to proceed through their normal growth cycle. The purpose of these experiments was to establish a Plactochron Index for Lupinus albus L. and to determine the effects of acute and chronic irradiation on development at the macro and microscopic levels. A Plastochron Index was calculated and used as an indirect time scale to evaluate the effects of gamma rays from a common base line. Acute radiation treatment lasted for a period of a few days, whereas chronic treatment was initiated at the seedling stage and lasted for the entire growth season. Vegetative plants were used to study the effects of acute radiation exposure on apical meristem morphology, Plastochron Index, phyllatoxis and gross morphology.
The relationships between changes in energy metabolism and the antioxidant defense system in the weed species Ipomoea triloba L. during seed germination and early seedling growth were investigated. The effects of some common allelochemicals on these parameters also were studied. Respiratory activity and the activities of alcohol dehydrogenase, superoxide dismutase, catalase, guaicol peroxidase, ascorbate peroxidase, glutathione reductase, and lipoxygenase were measured. Mitochondrial oxidative phosphorylation resumed shortly after the seed imbibition period, as indicated by considerable KCN-sensitive respiratory activity in embryos of I. triloba. The occurrence of superoxide dismutase, catalase, guaicol peroxidase, and lipoxygenase activities in the embryos, along with significant KCN-inse...
Plants release secondary metabolites into the soil that change the chemical environment around them. Exogenous abscisic acid (ABA) is an important allelochemical whose role in successional trajectories has not been examined. We hypothesized that ABA can accumulate in the soil through successional processes and have an influence on forest dynamics. To this end, we investigated the distribution of ABA in forest communities from early to late successional stages and the response of dominant species to the gradient of ABA concentrations in three types of forests from northern to southern China. Concentrations of ABA in the soils of three forest types increased from early to late successional stages. Pioneer species? litters had the lowest ABA content, and their seed germination and seedling ea...
The paper present the results of the study on D.U. (depleted uranium) contamination in the environment and possible effects on animal healths in the region o f Bujanovac. Samples of soil, feed, leaves, grass, lichen, moss, honey and water were collected randomly in 2003/2004 in the vicinity of the target area (500-1000 m) and 5 km from the target area. Activity of the radionuclides ({sup 226}Ra, {sup 232}Th, {sup 40}K, {sup 210}Pb, {sup 238}U, {sup 235}U, {sup 137}Cs, {sup 7}Be) in soils, grass, lichen, moss and honey was determined on Hp Ge detector (Canberra, relative efficiency 23%) by standard gamma spectrometry. Total alpha and beta activity in water was determined on proportional alpha/beta counter (Canberra 2400, efficiency for alpha emitters 11%, efficiency for beta emitters 30%). Non significantly higher values of concentrations of {sup 226}Ra, {sup 232}Th, {sup 238}U and {sup 235}U were measured in the immediate vicinity of the ...
During the weekend of September 2--3, 1984, a part of the wooden spillway for Steed Pond gave way and the pond slowly drained. Consideration is being given to leaving Steed Pond dry. Steed Pond has accumulated some of the uranium discharged from 300 Area operations and past surveys have shown that the uranium concentration in the sediments ranges between 20 and 531 pCi/gm. The recently completed aerial survey of the exposed area of Steed Pond showed that the uranium was widely spread in the sediments of Steed Pond. Until ground cover is established over the exposed pond sediments, they will be subject to erosion. As much as 90 tons of sediment could be eroded from the exposed sediments in Steed Pond the first year, but the erosion could be reduced to 5--15 tons by establishing a ground cover such as rye grass. Only about 40% of the eroded sediment would be delivered to Upper Three Runs Creek, because most of the eroded sediment deposited before it reaches Upper ...
Vaarst Vestervang (Denmark) comprises 16 villas and 1 communal building. The complex was designed by the inhabitants themselves with the aim of polluting the environment as little as possible. The land area constitutes 69.000 square meters where it is possible to grass animals. The document reports a measuring programme concerning the overall heat consumption as one of the main aims of the inhabitants is to save energy and thus contribute to the protection of the environment. The capacity of the solar collectors predominantly used in the building complex was 235 kWh/m{sup 2}. Supplementary heating is provided by boilers fired with wood. The measuring system is described in detail. Tables show the influence of heat transmission losses, ventilation, airing out of rooms, the angle of the sun`s rays within the buildings and heating needs on energy consumption. Energy consumption data is presented in relation to the forms of space and water heating utilized. Daily ...
The intention of this study is to show the high potential of remote sensing data to keep an eye on longterm processes in large regions with widespread tasks and questions. The results of two projects (sponsored by the BMBF - Ministry of Education and Science, Germany and the country of Saxony-Anhalt) are taken into account to give an impression of the chances provided by the application of hyperspectral airborne scanner data and satellite images. So these two projects focus at the applicability of various methods to use remote sensing data for a long- term monitoring of former lignite open-cast mining areas. Apart from the traditional pixelorientated analysis, the application and combination of new object orientated methods (e.g. segmentation, texture analysis) were investigated to distinguish between the following typical vegetation types: Spontaneous revegetation of plant communities; reforestation areas; recultivated grass seeding areas; area patterns of ...
Separate effects of ammonium (NH{sub 4} {sup +}) and nitrate (NO{sub 3} {sup -}) on boreal forest understorey vegetation were investigated in an experiment where 12.5 and 50.0 kg nitrogen (N) ha{sup -1} year{sup -1} was added to 2 m{sup 2} sized plots during 4 years. The dwarf-shrubs dominating the plant community, Vaccinium myrtillus and V. vitis-idaea, took up little of the added N independent of the chemical form, and their growth did not respond to the N treatments. The grass Deschampsia flexuosa increased from the N additions and most so in response to NO{sub 3} {sup -}. Bryophytes took up predominately NH{sub 4} {sup +} and there was a negative correlation between moss N concentration and abundance. Plant pathogenic fungi increased from the N additions, but showed no differences in response to the two N forms. Because the relative contribution of NH{sub 4} {sup +} and NO{sub 3} {sup -} to the total N deposition on a regional scale can vary substantially, the ...
Propylene and ethylene glycol deicers are commonly used at airports in the US and other countries to remove and retard the accumulation of snow and ice on aircraft. Deicers may not only enter water bodies without treatment, due to excessive storm-related flow, but also may expose terrestrial organisms to high concentrations through surface runoff. Most available toxicity data are for aquatic vertebrates and invertebrate species; this study examined effects on terrestrial and aquatic plants. Terrestrial plant species included both a monocot (rye grass, Lolium perenne) and a dicot (lettuce, Lactuca saliva). Aquatic species included a single cell alga (Selenastrum capricomutum), and an aquatic macrophyte (duckweed, Lemna minor). Glycol deicers were obtained in the formulated mixtures used on aircraft. Pure ethylene and propylene glycol were obtained from Sigma{reg_sign}. Parameters measured included germination, root and shoot length, survival, and growth. Formulated ...
The treatment and disposal of oily waters from oil production and refining processes represent an important technological pass for attendance of the ambient legislation and to the politics of the Cia of search of the environmental excellence. The reuse or reinjection of the co-produced water has been considered an interesting strategical alternative, however, the water quality requirement for these processes demands a pretreatment step, considering the exit effluent from primary and secondary treatment processes currently used. This work presents resulted of the polymeric resin development for tertiary treatment of oily waters with low oil and grasses content and fine solids, including the dissolved fraction. These resins can adsorb, in reversible form, organic components. Its high adsorption capacity is determined by the polarity, superficial area, range of porosity and a wide distribution of particle size and pore. Another important characteristic is the ...
European research in green energy production from crops has resulted in the development of full scale bioreactors that use energy crops as feedstock. Switchgrass has been touted as one of the most promising crops for energy production among several perennial grass species grown under moderate to hot climates. However, few studies have been conducted in colder climate conditions. This study examined the mesophilic methane yield of switchgrass grown under the cooler growing conditions that exist in northeastern North America. In 2007, switchgrass was harvested in late July, August and September and conserved as silage. The regrowth of plots harvested in late July was also harvested in late September as a two-cut strategy. A 30 L small-scale laboratory digester was used to anaerobically digest the switchgrass silage samples. Specific methane yield decreased considerably with advancing plant development, but was similar between the first harvest in late July and the ...
We evaluated the effectiveness of lime and red mud (by-product of aluminium manufacturing) to reduce metal availability to Festuca rubra and to allow re-vegetation on a highly contaminated brown-field site. Application of both lime and red mud (at 3 or 5%) increased soil pH and decreased metal availability. Festuca rubra failed to establish in the control plots, but grew to a near complete vegetative cover on the amended plots. The most effective treatment in decreasing grass metal concentrations in the first year was 5% red mud, but by year two all amendments were equally effective. In an additional pot experiment, P application in combination with red mud or lime decreased the Pb concentration, but not total uptake of Pb in Festuca rubra compared to red mud alone. The results show that both red mud and lime can be used to remediate a heavily contaminated acid soil to allow re-vegetation. - Red mud was effective in immobilising heavy metals in soil.
We evaluated the effectiveness of lime and red mud (by-product of aluminium manufacturing) to reduce metal availability to Festuca rubra and to allow re-vegetation on a highly contaminated brown-field site. Application of both lime and red mud (at 3 or 5%) increased soil pH and decreased metal availability. Festuca rubra failed to establish in the control plots, but grew to a near complete vegetative cover on the amended plots. The most effective treatment in decreasing grass metal concentrations in the first year was 5% red mud, but by year two all amendments were equally effective. In an additional pot experiment, P application in combination with red mud or lime decreased the Pb concentration, but not total uptake of Pb in Festuca rubra compared to red mud alone. The results show that both red mud and lime can be used to remediate a heavily contaminated acid soil to allow re-vegetation. - Red mud was effective in immobilising heavy metals in soil.
Sulfur dioxide emissions from an iron ore sintering plant have severely damaged vegetation up to 16 km northeast of the source. Concentric zones of increasing vegetation loss have formed around the point of maximum ground level concentration of the gas. Species diversity, sulfur and heavy metal concentrations in vegetation and soil amount to SO/sub 2/ injury were measured along a transect through the injury zones. Surrounding a central denuded area were zones dominated respectively by tussock-forming hair grass (Deschampsia flexuosa); low-growing shrubs and trailers (Sambucus pubens, Polygonum cilinode); higher-growing shrubs and suckering Populus tremuloides and Betula papyrifera) stunted forest tree species (Populus, Betula, Picea glauca, Abies Balsamea), and finally, normal boreal forest flora. Although SO/sub 2/ injury is continuing in this area, these zones now appear to be maintained primarily by severe erosion and destruction of suitable habitats for ...
Actinosynnema mirum Hasegawa et al. 1978 is the type species of the genus, and is of phylogenetic interest because of its central phylogenetic location in the Actino-synnemataceae, a rapidly growing family within the actinobacterial suborder Pseudo-nocardineae. A. mirum is characterized by its motile spores borne on synnemata and as a producer of nocardicin antibiotics. It is capable of growing aerobically and under a moderate CO2 atmosphere. The strain is a Gram-positive, aerial and substrate mycelium producing bacterium, originally isolated from a grass blade collected from the Raritan River, New Jersey. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first complete genome sequence of a member of the family Actinosynnemataceae, and only the second sequence from the actinobacterial suborder Pseudonocardineae. The 8,248,144 bp long single replicon genome with its 7100 protein-coding and 77 RNA ...
The heterokaryotic and vegetative diploid phases of Magnaporthe grisea, a fungal pathogen of grasses, have been characterized. Hyphal tip cells and conidia (vegetative spores) taken from these heterokaryons are auxotrophs with phenotypes identical to one or the other of the parents. M. grisea heterokaryons have completely septate hyphae with a single nucleus per cell. Heterokaryons have been utilized for complementation and dominance testing of mutations that affect nutritional characteristics of the fungus. Heterokaryons growing on minimal medium spontaneously give rise to fast-growing sectors that have the genetic properties expected of unstable heterozygous diploids. In fast-growing sectors, most hyphal tip cells are unstable prototrophs. The conidia collected from fast-growing sectors include stable and unstable prototrophs, as well as auxotrophs that exhibit a wide range of phenotypes, including many recombinant classes. Genetic linkage in meiosis has been ...
The study had three objectives: to collect information that explain the impact of the Aube storage center (C.S.A.) on environment and allow to evaluate the consequences for man, secondly, to build a referential for any future inquiry or follow-up, thirdly, to allow to the local commission of information to elaborate an information towards the side residents and local actors that take into account their questions. Trees, waters, sediments, soils, grass, products of gardens and vineyards were the object of sampling, their dosimetry is given in this report. Other dosimetry measures were made along the nuclear site and the results are equally in this report. (N.C.)
Organic waste, as a main constituent of municipal solid waste, has as well as solid biomass a high potential for biogas generation. Despite the importance of biogas generation from these materials, the availability of large-scale biogas processes lacks behind the demand. A newly developed double-stage solid-liquid biogas process, consisting of an open hydrolysis stage and a fixed-bed methane reactor, allows the biogas production from almost all biodegradable solid waste and renewable resources like maize, grass, sugar cane, etc. Furthermore, residues from industrial processes, like the glycerine waste water from biodiesel production, can also be converted into biogas successfully. Due to the strong separation of hydrolysis and methanation, the process is extremely stable. No malfunction has been detected so far. The open hydrolysis releases CO_2 and allows oxidation of sulfur. Consequently, the biogas has a high methane (>72%) and low H_2S concentration (<100 ...
Homozygous transgenic cotton (Gossypium hirsutum L.) plants that accumulated glycinebetaine (GB) in larger quantities were more tolerant to salt than wild-type (WT) plants. Four transgenic lines, namely 1, 3, 4, and 5, accumulated significantly higher levels of GB than WT plants did both before and after salt stress. At 175 and 275?mM NaCl, seeds of all the transgenic lines germinated earlier and recorded a higher final germination percentage, and the seedlings grew better, than those of the WT. Under salt stress, all the lines showed some characteristic features of salt tolerance, such as higher leaf relative water content (RWC), higher photosynthesis, better osmotic adjustment (OA), lower percentage of ion leakage, and lower peroxidation of the lipid membrane. Levels of endogenous GB in ...
The bacterial strain E1R-j, isolated as an endophyte from wheat roots, exhibited high antifungal activity to Gaeumannomyces graminis var. tritici (Ggt). Strain E1R-j was identified as Bacillus subtilis based on morphological, physiological and biochemical methods as well as on 16S rDNA analysis. This strain inhibited mycelium growth in vitro of numerous plant pathogenic fungi, especially of Ggt, Coniothyrium diplodiella, Phomopsis sp. and Sclerotinia sclerotiorum. In greenhouse experiments, soil drenches with cell densities of 106, 109 and 1012CFU ml-1 E1R-j reduced significantly take-all disease, caused by Ggt, in wheat seedling by 62.6%, 68.6% and 70.7%, respectively, compared to the inoculated control, 4weeks after sowing. Growth parameters such as lengths and fresh weights of roots and...
The biomedical and ecological interest for the microwave impact on the Earth biosphere is continuously increased since the industrial, military and communication activities strongly contribute to the electromagnetic stress of living bodies. In the next the authors present some of the main results obtained regarding the microwave exposure of various types of biological material: bacteria, fungi, young plant seedlings, dry seeds, animal tissues. The electromagnetic exposure was carried out in open space in well controlled environmental conditions by using 10.75 GHz/1 m W cm{sup -2} microwaves. Biochemical assays and cytogenetic tests have been carried out to reveal the changes induced post irradiation. The response of some pathogen bacteria, have been emphasized by means of turbidimetric measurements - the stimulatory effect being noticed at the level of the microbial population density (the stimulation of the human body microbial flora seems to be one of the side ...
Crop water demand in the Okanagan Basin was determined for 1961 to 1990, 2010 to 2039, 2040 to 2069, and 2070 to 2099. Daily station temperature data were spatially interpolated to a 1 x 1 km grid and adjusted for elevation. Daily precipitation data were estimated across four climatic regions. Output from three global climate models (GCM), CGCM2, CSIROMk2 and HadCM3 was used to create future daily climate. Daily potential evapo-transpiration (grass reference) was estimated from an empirical relationship between Bellani-plate atmometer readings, temperature and extra-terrestrial solar radiation, and then modified by crop coefficients for all crops except pasture. Depending on GCM, projected water demand increased by 12-20% (2010 to 2039), 24-38% (2040 to 2069) and 40-61% (2070 to 2099). Possible elevated CO{sub 2} effects on stomatal conductance which may reduce water demand were not accounted for. Comparisons with modeled Okanagan Lake inflows indicated that, on ...
No living analogue exists for the hypothetical early hominid hard/tough-seed, coarse-root-eating, and bone-crushing masticatory adaptation. To investigate possible microdamage/microwear to dental enamel caused by such usage, puncture-crushing experiments were carried out on single human teeth, using an Instron compression apparatus on the following six test materials: Makapansgat Limeworks chert (e.g., taphonomy), fresh steer longbone, mongongo nuts, Grewia berries, Carob beans, and wild-onion bulbs. Pairs of extracted unworn third molars were utilized, with one tooth acting as the control. The teeth were mounted, ultrasonically cleaned, and two-stage replicas made with a vinyl polysiloxane elastomer and araldite epoxy resin. After Instron loading and materials failure (1.2-395.0 kg) the test items and the crowns were prepared for comparison with scanning electron microscopy and dispersive x-ray elemental analysis and mapping. The results revealed that although grit adhering to food ...
The purpose of the present work is to investigate the effects of matrix resin and fiber content on the behavior of fatigue crack propagation in continuous-glass-fiber-mat reinforced CP-resin composites. For this purpose, ductile matrix resin and brittle one are used. These two kinds of resins have the characteristic that the elastic modulus and tensile strength are nearly the same with each other while the elongation is different. The composite specimens are made of these resins and continuous grass fiber mat of 20 wt.% and 60 wt% fiber contents. The fatigue crack propagation test was conducted by using the tapered DCB specimens to control the stress intensity factor range, {delta}K, during the test. The results obtained are as follows; (1) The relation between the crack propagation rate, da/dN, and {delta}K for all the present materials is shown by a straight line in logarithmic representation. (2) For the composites of 20 wt.% fiber content, the da/dN of the ...
A Lurgi baseline study was requested by the DOE/GRI Operating Committee of the Joint Coal Gasification Program for the purpose of updating the economics of earlier Lurgi coal gasification plant studies for the production of substitute natural gas (SNG) based on commercially advanced technologies. The current study incorporates the recent experience with large size Lurgi plants in an effort to improve capital and operating costs of earlier plant designs. The present coal gasification study is based on a mine mouth plant producing 250 billion Btu (HHV) per day of SNG using the Lurgi dry bottom coal gasification technology. A Western subbituminous coal was designated as the plant food, obtained from the Rosebud seam at Colstrip, Montana. This study presents the detailed description of an integrated facility which utilizes coal, air, and water to produce 250 billion Btu (HHV) per day of SNG. The plant consists of coal handling and preparation, twenty-six Lurgi dry bottom gasifiers, shift ...
Soil erosion and small annual additions of organic matter from plant-sources are the major causes of low organic-matter content in our soils. The tops of the plants, fallen to the soil- surface, remain there are incorporated, the plant-roots, shrubs, grasses. And other native plants contribution much towards the soil organic matter. Populus spp. Are grown commonly around farmers' fields in the state of Azad Jammu and Kashmir. A pot-experiment was conducted to study the effect of addition of populus euramericana leaves on various physical and chemical characteristics of the soil. Soil was kept at field-capacity level and incubated at room temperature for 10 months after adding 25, 50, and 75 g of Populus curamericana leaves per pot. Changes in organic-matter content. PH, cation-exchange capacity extractable potassium, water-holding capacity, and bulk density were investigated, after incubation for 6,8,and 10 months. There was a linear increase in organic-matter ...
["3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 37"0C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as #alpha#-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic procedures resulted in ...
Results are presented of trials in W. Germany involving Populus tremula X P. tremuloides. In a nursery in late August - early September 1971, some 1300 buds from 38 selected 3-yr-old hybrid aspen seedlings were grafted into T-slits at nodes 10-20 cm above root' collars of 1 and a half yr-old hybrid aspen stock (products of controlled crossings, and in some cases of similar parentage to the transplanted buds). In spring 1972, each stock (from which its own buds were removed) was cut back to a 'peg' 15-20 cm above the level of the graft; the 'peg' was later used to support the new shoot developed from the transplanted bud. By Sept. 1972, 33% of grafts were successful, the success rate being significantly different (3-67%) within clones; average height of scion shoots ranged from 79 to 375 cm (no significant difference between clones). In spring 1973, some 190 grafts from 35 clones were row-planted in the open (3 m between ...
One-year-old seedlings of mulberry, the variety of Shinichinose, were used to fix /sup 14/CO/sub 2/ for 10 minutes under light of 18,000 lux at 28 deg C. Photosynthesis was continued after that in the air not containing /sup 14/CO/sub 2/. The specimens were collected immediately after and 10 and 30 minutes after the /sup 14/CO/sub 2/ fixation, divided into mesophyll, vein and stem bark, frozen in liquid N/sub 2/, and the contents of sucrose, glucose and fructose and their radioactivity were measured. The ratio of the radioactivity incorporated into sucrose to the total radioactivity incorporated into each tissue was very large, and the incorporation into glucose or fructose was very little. The content of sucrose was also larger than that of the other sugars in all the tissues. These findings showed that the photosynthates were translocated mainly in the form of sucrose. The ratio of specific radioactivity (dpm/mg sugar) in the mesophyll to that in the vein was ...
The impact of increasing atmospheric C0{sub 2} has not been fully evaluated on western coniferous forest species. Two year old seedlings of Pinusponderosa were grown in environmentally controlled chambers under increased C0{sub 2} conditions for 6 months. These trees exhibit morphological, physiological, and biochemical alterations when compared to our controls. Analysis of whole plant biomass distribution has shown no significant effect to the root to shoot ratios, however needles subjected to elevated C0{sub 2} exhibited an increased overall specific needle mass and a decreased total needle area. Morphological changes at the needle level included decreased mesophyll to vascular tissue 91 ratio and variations in starch storage in chloroplasts. The elevated CO{sub 2} increased internal CO{sub 2} concentrations and assimilation of carbon. Biochemical assays revealed that ribulose-bisphosphate carboxylase specific activities increased on per unit area basis with ...
One set of hypotheses offered to explain the decline of red spruce (Picea rubens Sarg.) in eastern North America focuses on the effect of acidic deposition on soil chemistry changes that may affect nutrient availability and root function. Long-term soils data suggests that soil acidification has occurred in some spruce stands over the past 50 yr, with plant uptake and cation leaching both contributing to the loss of cations. Studies of tree ring chemistry also have indicated changes in Ca/Al and Mg/Al ratios in red spruce wood, suggesting increases in the ionic strength of soil solution. Irrigation studies using strong acid inputs have demonstrated accelerated displacement of base cations from upper horizons. Spruce-fir (Abies spp.) nutrient budgets indicate that current net Ca and Mg leaching loss rates are of the same order of magnitude as losses to whole tree harvest removals, spread out over a 50-yr rotation. For most cations, red spruce foliar nutrient levels decline with ...
Nineteen lesion mimic mutants (xsl1-19) of japonica rice Xiushui11 were obtained by ?-rays irradiation treatment. All mutants belonged to whole life lesion mimic. Lesion mimic of mutants didn't largen after tillering stage, leaves didn't wither, and no effect on the plants exsert spikes and seed. When the highest temperature in day exceeded 32 degree C in seedling stage, lesion mimic of all mutant expect xsl19 disappeared. Under 32 degree C, lesion mimic would appear gradually, and symptoms weren't inhibited by high temperature after 5 leaf stage. The plant heights of all lesion mimic mutants were 47.56-63.54 cm in the tillering stage, and that of CK was 83.75 cm; but the dwarf phenomenon of mutants only appeared before tillering stage, and didn't affect plant heights finally; the heading dates of mutants were the same to the CK, the ear length of all mutants were 9.43-15.19 cm, and that of CK was 16.41 cm; the total grain quantity per spike of all mutants were ...
The objective of this research is to study the effects of elevated ozone, carbon dioxide and their combination on ultrastructural, physiological and biochemical responses of Scots pine needles and how these effects are reflected to photosynthesis, carbohydrate and nutrient allocation and finally to shoot and root growth of trees. In addition the interactions of the studied trees and mycorrhizal fungi as well as insect herbivores are studied. The exposures have been running only for two growing periods and it seems necessary to continue the experiment over the third growing season in 1996. Since the analyses are partially incomplete, only preliminary conclusions are possible at the moment. The slightly increased shoot growth and needle width and increased amount of starch in chloroplasts point to the slight stimulating effect of elevated CO{sub 2} among the chamber treatments. Altogether the growth of the seedlings was best in the chamberless treatment indicating a ...
Spontaneous mutation has been discovered and utilized in domestication of narrow-leafed lupin (Lupinus angustifolius L.). As the result of the domestication, lupin has become a dominant grain legume crop in Western Australia. Facing the new challenge of developing herbicide tolerance cultivars, chemical mutagenesis has been used to create new tolerance to herbicide. This paper reports the characterization of two lupin mutants (Tanjil-AZ-33 and Tanjil-AZ-55) that are highly tolerant to metribuzin herbicide. A dose response study over 8 doses revealed that Tanjil-AZ-33 was 6 times more tolerant to metribuzin than the original parental cultivar Tanjil by measure of LD50. This mutant Tanjil-AZ-33 is the most tolerant germplasm in narrow-leafed lupin. Both mutants also maintain the high resistance to the disease anthracnose as cv Tanjil. Seed yield based on small field plots (3.6 m"2) under irrigation was 4.2 t/ha for Tanjil-AZ-33 and 1.9 t/ha for Tanjil when the ...
Rice is a very important food staple that feeds more than half the world's population. Two major Asian cultivated rice (Oryza sativa L.) subspecies, japonica and indica, show significant phenotypic variation in their stress responses. However, the molecular mechanisms underlying this phenotypic variation are still largely unknown. A common link among different stresses is that they produce an oxidative burst and result in an increase of reactive oxygen species (ROS). In this study, methyl viologen (MV) as a ROS agent was applied to investigate the rice oxidative stress response. We observed that 93-11 (indica) seedlings exhibited leaf senescence with severe lesions under MV treatment compared to Nipponbare (japonica). Whole-genome microarray experiments were conducted, and 1,062 probe sets were identified with gene expression level polymorphisms between the two rice cultivars in addition to differential expression under MV treatment, which were assigned as Core ...
We report here on an experimental system that utilizes ion-selective microelectrodes to measure the electrochemical potential gradients for H"+ and K"+ ions within the unstirred layer near the root surface of both tact 4-day-old corn seedlings and corn root segments. Analysis of the steady state H"+ and K"+ electrochemical potential gradients provided a simultaneous measure of the fluxes crossing a localized region of the root surface. Net K"+ influx values obtained by this method were compared with unidirectional K"+ ("8"6Rb"+) influx kinetic data; at any particular K"+ concentration, similar values were obtained by either technique. The ion-specific microelectrode system was then used to investigate the association between net H"+ efflux and net K"+ influx. Although the computed H"+K"+ stoichiometry is dependent upon the choice of diffusion coefficients, the values obtained were extremely variable, and net K"+ influx rarely appeared to be charge-balanced by H"+ ...
Field cage studies were carried out to evaluate the F_1 sterility technique for population suppression of the pink bollworm, Pectinophora gossypiella (Saunders), in cotton. For this purpose, six field cages (1.8 m x 1.8 m x 1.8 m) were placed over cotton seedlings in the field. Five pairs of laboratory reared, untreated adult moths were released in all six cages during the first week of August. In addition, on the same data 100 pairs of adults, following irradiation of the mature pupae at 100 Gy, were released in two cages and 250 such pairs of irradiated adults in two other cages in ratios of 20:1 and 50:1 (irradiated:normal), respectively. The results of per cent larval infestation in the rosette blooms in different field cages indicated that larval infestation in the flowers was significantly lower (4.93%) in cages where the moths were released at the 50:1 ratio than in cages where moths were released at the 20:1 ratio (6.71%). Larval infestation in the flowers ...
To evaluate the role of phytochelatins and metallothioneins in heavy metal tolerance of black mangrove Avicennia germinans, 3-month-old seedlings were exposed to cadmium or copper for 30 h, under hydroponic conditions. Degenerate Mt2 and PCS primers were synthesized based on amino acid and nucleotide alignment sequences reported for Mt2 and PCS in other plant species found in GenBank. Total RNA was isolated from A. germinans leaves and two partial fragments of metallothionein and phytochelatin synthase genes were isolated. Gene expression was evaluated with reverse transcripatase-polymerase chain reaction (RT-PCR) amplification technique. Temporal analysis showed that low Cd{sup 2+} and Cu{sup 2+} concentrations caused a slight (but not significant) increase in AvMt2 expression after a 16 h exposure time, while AvPCS expression showed a significant increase under the same conditions but only after 4 h. Results strongly suggest that the rapid increase in AvPCS ...
To evaluate the role of phytochelatins and metallothioneins in heavy metal tolerance of black mangrove Avicennia germinans, 3-month-old seedlings were exposed to cadmium or copper for 30 h, under hydroponic conditions. Degenerate Mt2 and PCS primers were synthesized based on amino acid and nucleotide alignment sequences reported for Mt2 and PCS in other plant species found in GenBank. Total RNA was isolated from A. germinans leaves and two partial fragments of metallothionein and phytochelatin synthase genes were isolated. Gene expression was evaluated with reverse transcripatase-polymerase chain reaction (RT-PCR) amplification technique. Temporal analysis showed that low Cd"2"+ and Cu"2"+ concentrations caused a slight (but not significant) increase in AvMt2 expression after a 16 h exposure time, while AvPCS expression showed a significant increase under the same conditions but only after 4 h. Results strongly suggest that the rapid increase in AvPCS expression ...
Full text of publication follows: General simulation objectives of any fire analysis are macroscopic in nature and deals with the grass data in respect of fire/smoke spread, structural behaviour, environmental conditions etc. However, the accuracy of predicting such macroscopic parameters is a strong function of several other microscopic parameters which govern the overall macroscopic behaviour. Some of the microscopic parameters of interesting such analysis could be buoyancy induced stable/unstable flows, relative flame behaviour, baroclinic velocity distribution etc. Only the field based fire modelling approach is capable of calculating several of these by way of detailed CFD based field modelling. One of the best known tool that could be employed for such studies is the Fire Dynamics simulator (FDS) from NIST with its popular LES based fire modelling approach. Advanced LES based fire modelling scores over the conventional RANS based Computational fire modelling ...
Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract methylmercury from their growth substrate and ...
{sup 14}C is a is a long-lived beta-emitting nuclide (T{sub 1/2} = 5730 years) produced naturally in the upper atmosphere as a result of reactions between neutrons and stable {sup 14}N({sup 14}N(n,p){sup 14}C). Although in a lesser extent, nuclear power plants produce {sup 14}C as well during their routine operation. Since it is converted in {sup 14}CO{sub 2} and mixed throughout the atmosphere, it is incorporated into plant tissues, via photosynthesis process, and hence in food chain. Because of the biological importance of {sup 14}C and long half-life, it is of interest to quantify the amounts released by nuclear industry. The Brazilian nuclear central named Nuclear Central Admiral Alvaro Alberto (CNAAA) has two nuclear reactors of PWR type in operation, Angra I (657 MWe) and Angra II (1350 MWe), and one under construction, Angra III (1309 MWe PWR). The aim of this study was to determine the strength of the sources and the {sup 14}C content in the environment through analyses of air, ...
In 1996, a field-scale phytoremediation demonstration project was initiated and managed by the U.S. Air Force at a site in western Fort Worth, Texas, using a plantation of 1-year-old stems harvested from branches of eastern cottonwoods during the dormant season (whips) and a plantation of 1-year-old eastern cottonwood seedlings (calipers). The primary objective of the demonstration project was to determine the effectiveness of eastern cottonwoods at reducing the mass of dissolved trichloroethene transported within an alluvial aquifer. The U.S. Geological Survey conducted a study, in cooperation with the U.S. Air Force, to determine water-level variations and their effects on tree growth and mortality and on the biogeochemical system at the phytoremediation site. As part of the study, water-level and water-quality data were collected throughout the duration of the project. This report presents water-level variations at periodic sampling events; data from August ...
Sesame varieties/genotypes showed a good response to radiation with gamma rays and treatments with EMS. In M_1 both gamma rays and EMS influenced germination, seedling height, survival of plants and pollen fertility/sterility, producing deleterious effects on these characters. Compared to black seeded genotypes, white seeded ones are more susceptible to radiation. Both gamma rays and EMS produced various types of morphological variations in M_2 generation. These were dwarf plant mutants, mottled and fleshy leaved mutants (sterile), fasciated stem, flower colour, altered phyllotaxy, early, uniculm, capsule size variations, multiple capsule/leaf axil, seed coat colour variations, indehiscent and semi-indehiscent type mutants. Moreover, studies on quantitative characters including seed yield revealed the induction of mutants in both positive and negative directions for such traits which made a good scope of selection of desirable mutants in M_2 generation. Mutants ...
When biomass is used as fuel for thermal conversion plants, minerals from the fuel can be responsible for major problems. Generally, these problems are associated with the existence and development of low melting compounds or eutectics, which form sticky layers. In a fluidised bed, this can result in bed-agglomeration and defluidisation. This causes local high temperature, which often accelerates the process. It ultimately can lead to a completely sintered bed content with a glassy phase gluing the bed particles together and shut-down of the plant. The main objective of the title project is to develop a methodology to predict ash/bed agglomeration and sintering problems, to indicate related problems and, furthermore, to identify solution methods to make different types of biomass streams more viable for energy production. Within the present study, selected fuels are subjected to different existing methods together with some new ones, in order to determine the agglomeration temperature. ...