989 resultados para germination percentage
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Aughinish Alumina Limited (AAL) have an obligation by terms of their Integrated Pollution Control Licence (IPCL) and Planning Permission to establish vegetation on the red mud stack at their plant at Aughinish, Co. Limerick. High pH and high exchangeable sodium percentage are the main known factors limiting the establishment of vegetation on red mud. Gypsum addition has been known to assist in alleviating these problems in other countries. However, there is no experience or published information on red mud rehabilitation under Irish conditions. Red mud with organic and inorganic waste-derived ameliorants as well as selected grassland species were examined under laboratory controlled environment conditions as well as in field plot trials. Also, in order that it would be economically achievable, the research utilised locally available waste products as the organic amendments. Screening trials found that physical constraints severely limit plant germination and growth in red mud. Gypsum addition effectively lowers pH, exchangeable sodium percentage and the availability of A1 and Fe in the mud. A strong relationship between pH, ESP and A1 levels was also found. Gypsum addition increased germination percentages and plant growth for all species investigated. Greenhouse trials demonstrated that organic wastes alone did not greatly improve conditions for plant growth but when used in conjunction with gypsum plant performances for all species investigated was significantly increased. There was a high mortality rate for grasses in non-gypsum treatments. An emerging trend of preferential iron uptake and calcium deficiency in non-gypsum treatments was found at pot screening stage. Species also displayed manganese and magnesium deficiencies.
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1 - The Author, in this 3 thd. contribution, concludes the study of the biology and ecology of the species Tristicha trifaria (Willd.) Spreng. and Mourera aspera (Bong.) Tul., both of the Piracicaba Fall. 2 - According to the results of Dr. Peter van Royen (State Herbarium of Leiden, Holland), who made a complete revision of Podostemaceae of the Piracicaba Fall, the species Tristicha hypnoides (St. Hil.) Spreng. var. Hilarii Tul. and Mnioppsis Glazioviana Warm, correspond, respectively, to theTristicha trifaria (Willd.) Spreng. and Mniopsis weddelliana Tul. Apinagia Accorsii Toledo was transferred by Royen to the genus Wettsteiniola. So, its new name is Wettsteiniola accorsii (Toledo) v. Royen. 3 - Propagation by seeds may occur in the following places: a) placenta of partially open fruits; b) external and internal walls of the open capsules; c) pedicels of the fruits; d) remains of rhizomes, branches, etc. e) organic residues accumulated in water holes in the fall; f) clean rocks, in which the little groups of seedlings seems to be a colony of algae. Seeds adhere to the substrata above by means, of a mucilage produced by the transformation of the external integuments in contact with water. 4 - In the growth of the four species below it was found in Piracicaba Fall conspicuous zoning so scattered: a) Wettsteiniola accorsii (Toledo) v. Royen, in rocks situated just within the water fall, where velocity of the current and aeration of the water are very high. b) Tristicha trifaria (Willd.) Spreng. and Mniopsis weddelliana Tul., in rocks at some distance (100 m more or less) upstream until near the bridge across the river. c) Mourera aspera (Bong.) Tul., 300 m upwards the bridge. 5- During 1949, the ecological conditions of the Piracicaba Fall were changed due to the following factors: a) dry season very long, begining from last period of June until 30 november; b) stopping, during four months, of water from the Atibaia river (one of the components of Piracicaba river) near to the city of Americana, in the place where a new station of the Companhia Paulista de Força e Luz was build. In consequence, most of the Podostemaceae died. On the dry rocks there were only fruits and dried plants. 6 - Tristicha trifaria has the same biological and ecological behavior as the Mniopsis weddelliana,. 7 - The vegetative propagation of Tristicha trifaria is made by increasing of its branches, production of stolons with vegetatives buds and regeneration of old parts in especial conditions of water and aeration. 8 - Mourera aspera has the same vegetative propagation as the Wettsteiniola accorsii; it produces stolons (in very little percentage) with vegetative buds, branches of the rhizomes and regeneration of active old parts. 9 - Frequently, there is, on the plants an accumulation of sand, silt, loam, organic substances, and so on. The quantity of material stored depends of the purity of the water, of the morphology of the plants and of the situation on the fall. 10 - In extrem conditions of dry heat, the surviving of the species in its habitat depends exclusively from germination of seeds in the mentioned substrata. Exceptionally, some plants survive in a few water pockets full with the weak remaining current.
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The indices found are analysed as a whole and general conclusions are drawn from them which may be of use in understanding many of the problems offered by the local flora (Ilhéus). The first column of the tables presented indicates the biological form of the species, showing the nature of the flora and the constitution of the climax. A total of 200 species of phanerophyta were found; 69 macrophanerophyta (trees), 54 are mesophanerophyta (treelets) and 77 are nanophanerophyta (shrubs). The macrophanerophyta are consequently considered as dominants and the meso-and nanophanerophyta as codominants (the biological forms: chamaephyta, hemicriptophyta, criptophyta, geophyta, therophyta, epiphyta and hydrophyta are subdominants), the more so as the first cover 80% and the others more or less 50%. This points to a climax of trees and a local vegetation mainly composed of trees also. The smaller forms are left out as they are beyond the present scope of this sort of wort in Brazil. The third column of ecological formulae indicates the reaction of the constituent species to light (C = sciophilous, F = photophilous and I = indifferents), the biological types of vegetation (H = hygrophytes, X = xerophytes and M = mesophytes) and the fidelity of the species to the climax. Of the species studied: 25 are pioneers (P. Table I), 63 are accidentals (A. Table II), 35 are companion species (O. Table III), 19 show preferences (E. Table with vitality Vn), 44 are selective (S. Table V) and 13 exclusive species (L. Table VI). This leads to the conclusion that the vegetation of the region is in full reconstitution. As to the ecological characteristics of the 200 species studied, 89 are either pioneers (a class separated by the author) or accidentals; this means that the devastated zones are being reconstituted in the subsere both with members of the prisere and alien species. Of the remaining species, 54 are companion, or accompanying species, which appear in most subclimax, serclímax and quasiclimax associations, and 57 are real constituents of the local climax. As all the species except the pioneers, selectives and exclusives (xerophytes and mesophytes) may be considered as hygrophytes this type evidently predominantes in the region and may constitute a hygrophilous serclimax and quasiclímax. In regard to light 101 are sciophilous, 32 indiferents and 67 photophilous. This leads to the conclusion that the vegetation comprises mainly tolerant species, showing the hygrophilous and mesophilous character of the region with a vegetation composed mostly of trees. The presence a large number of sciophilous species is easy to understand as the hygrophilous and mesophilous habitats and the dominance of trees favour the germination and growth of tolerant species. The last two columns analyse the percentage of individuals present and the occurrent classes to which they belong: 92 species vary between 1 and 9%; 50 between to 10 and 19%; 36 between 20 and 29%; 14 between 30 and 39%; and 8 between 40 and 49%. Only 8 species belong to occurrence class V; 14 to classe IV; 36 to class III; 50 to class II; and 92 to class I. This leads to the conclusion that the local formation is very unsociable and very complex, though the median coverture is 80% and the number of species is very large. The analysis of the data also shows that the climax is being reconstituted in the subsere with elements drawn from the prisere and alien species introduced either by man (following desvastation) or by other consequent factors (such as brusque changes of microclimates due to total or partial destruction). This modifies the subclimax appreciably and apparently also the climax of the local regional subsere. As a final conclusion it is suggested that as in the subsere the pioneer formation is xerophilous, the prisere also beging as a xerosere; but as there are and probably always were hydrophilous formation evolving in the same climate, the local climax is composed of species with medium exactions, that is of relative mesophites.
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Abstract: The use of an enriched CO2 atmosphere in tree nurseries has been envisaged as a promising technique to increase productivity and to obtain seedlings with a higher root/shoot ratio, an essential trait to respond to water stress in Mediterranean-type ecosystems. In that framework, we have analyzed the effects of three levels of atmospheric CO2 concentration (350, 500 and 700 ppm) on the germination rate, growth and morphology of seedlings of two Mediterranean oaks used in reforestation programs: the evergreen Quercus ilex L. and the deciduous Quercus cerrioides Wilk. et Costa. CO2 enrichment increased the germination rate of Q. cerrioides (from 70±7 to 81±3 %) while it decreased that of Q. ilex (from 71±10 to 41±12 %). Seedlings of both species increased approximately 60% their total biomass in response to CO2 enrichment but at two different CO2 concentrations: 500 ppm for Q. cerrioides and 700 ppm for Q. ilex. This increase in seedlings biomass was entirely due to an augmentation of root biomass. Considering germination and biomass partitioning, an enriched CO2 atmosphere might not be appropriate for growing Mediterranean evergreen oaks, such as Q. ilex, since it reduces acorn germination and the only gains in root biomass occur at a high concentration (700 ppm). On the other hand, a moderate CO2 enrichment (500 ppm) appears as a promising nursery technique to stimulate the germination, growth and root/shoot ratio of deciduous oaks, such as Q. cerrioides. Resumen: El uso de una atmósfera enriquecida en CO2 durante la fase de vivero puede contribuir a aumentar la producción viverÃstica, a la vez que ayudar a conseguir plántulas con una mayor relación biomasa subterránea/biomasa aérea, más adecuadas para hacer frente al severo estrés hÃdrico que generalmente limita el éxito de las repoblaciones en el clima Mediterráneo. En este estudio hemos analizado el efecto de tres niveles de abonado carbónico atmosférico (350, 500 y 750 ppm) en la germinación y morfologÃa de plántulas de encina (Quercus ilex) y roble cerrioide (Quercus cerrioides). Una atmósfera enriquecida en CO2 incrementó la germinación de Q. cerrioides (de 70±7 a 81±3 %) mientras que disminuyó la de Q. ilex (de 71±10 a 41±12 %). Las plántulas de ambas especies incrementaron aproximadamente un 60% su biomasa en respuesta a una mayor concentración de CO2, aunque esta respuesta se produjo a diferentes dosis: 500 ppm en Q. cerrioides y 700 ppm en Q. ilex. El aumento en la biomasa total de las plántulas se debió enteramente a un mayor desarrollo de su sistema radical, Considerando tanto la germinación como los efectos sobre la relación biomasa subterránea/biomasa aérea, una atmósfera enriquecida en CO2 no parece ser un tratamiento adecuado para la producción en vivero de plántulas de Q.ilex, puesto que diminuye su germinación y solo aumenta su sistema radicular a dosis muy elevadas (700 ppm). Por el contrario, un aumento moderado en la concentración de CO2 (500 ppm) aparece como una técnica interesante para estimular el crecimiento y obtener plántulas de Q. cerrioides con un sistema radical más desarrollado.
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Lean meat percentage (LMP) is the criterion for carcass classification and it must be measured on line objectively. The aim of this work was to compare the error of the prediction (RMSEP) of the LMP measured with the following different devices: Fat-O-Meat’er (FOM), UltraFOM (UFOM), AUTOFOM and -VCS2000. For this reason the same 99 carcasses were measured using all 4 apparatus and dissected according to the European Reference Method. Moreover a subsample of the carcasses (n=77) were fully scanned with a X-ray Computed Tomography equipment (CT). The RMSEP calculated with cross validation leave-one-out was lower for FOM and AUTOFOM (1.8% and 1.9%, respectively) and higher for UFOM and VCS2000 (2.3% for both devices). The error obtained with CT was the lowest (0.96%) in accordance with previous results, but CT cannot be used on line. It can be concluded that FOM and AUTOFOM presented better accuracy than UFOM and VCS2000.
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BACKGROUND AND AIMS: The Senecio hybrid zone on Mt Etna, Sicily, is characterized by steep altitudinal clines in quantitative traits and genetic variation. Such clines are thought to be maintained by a combination of 'endogenous' selection arising from genetic incompatibilities and environment-dependent 'exogenous' selection leading to local adaptation. Here, the hypothesis was tested that local adaptation to the altitudinal temperature gradient contributes to maintaining divergence between the parental species, S. chrysanthemifolius and S. aethnensis. METHODS: Intra- and inter-population crosses were performed between five populations from across the hybrid zone and the germination and early seedling growth of the progeny were assessed. KEY RESULTS: Seedlings from higher-altitude populations germinated better under low temperatures (9-13 °C) than those from lower altitude populations. Seedlings from higher-altitude populations had lower survival rates under warm conditions (25/15 °C) than those from lower altitude populations, but also attained greater biomass. There was no altitudinal variation in growth or survival under cold conditions (15/5 °C). Population-level plasticity increased with altitude. Germination, growth and survival of natural hybrids and experimentally generated F(1)s generally exceeded the worse-performing parent. CONCLUSIONS: Limited evidence was found for endogenous selection against hybrids but relatively clear evidence was found for divergence in seed and seedling traits, which is probably adaptive. The combination of low-temperature germination and faster growth in warm conditions might enable high-altitude S. aethnensis to maximize its growth during a shorter growing season, while the slower growth of S. chrysanthemifolius may be an adaptation to drought stress at low altitudes. This study indicates that temperature gradients are likely to be an important environmental factor generating and maintaining adaptive divergence across the Senecio hybrid zone on Mt Etna.
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The goal of this study was to evaluate changes in plasma human immunodeficiency virus (HIV) RNA concentration [viral load (VL)] and CD4+ percentage (CD4%) during 6-12 weeks postpartum (PP) among HIV-infected women and to assess differences according to the reason for receipt of antiretrovirals (ARVs) during pregnancy [prophylaxis (PR) vs. treatment (TR)]. Data from a prospective cohort of HIV-infected pregnant women (National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study) were analyzed. Women experiencing their first pregnancy who received ARVs for PR (started during pregnancy, stopped PP) or for TR (initiated prior to pregnancy and/or continued PP) were included and were followed PP. Increases in plasma VL (> 0.5 log10) and decreases in CD4% (> 20% relative decrease in CD4%) between hospital discharge (HD) and PP were assessed. Of the 1,229 women enrolled, 1,119 met the inclusion criteria (PR: 601; TR: 518). At enrollment, 87% were asymptomatic. The median CD4% values were: HD [34% (PR); 25% (TR)] and PP [29% (PR); 24% (TR)]. The VL increases were 60% (PR) and 19% (TR) (p < 0.0001). The CD4% decreases were 36% (PR) and 18% (TR) (p < 0.0001). Women receiving PR were more likely to exhibit an increase in VL [adjusted odds ratio (AOR) 7.7 (95% CI: 5.5-10.9) and a CD4% decrease (AOR 2.3; 95% CI: 1.6-3.2). Women receiving PR are more likely to have VL increases and CD4% decreases compared to those receiving TR. The clinical implications of these VL and CD4% changes remain to be explored.
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Entomofauna associated to fruits and seeds of two species of Enterolobium Mart. (Leguminosae): Harm or benefit? The aims of the present study were to identify the entomofauna associated to the fruits and seeds of Enterolobium contortisiliquum (Vell.) Morong and Enterolobium timbouva Mart. (Leguminosae), as well as to determine relationships among insects and the possible harm and/or benefit stemming from these associations. Fruit infestation was evaluated and the insects were identified. Seed consumption (%) and the germination of predated seeds (%) were determined. The fruits of E. contortisiliquum exhibited a high percentage of infestation (91%). The most representative species in the fruits were Lophopoeum timbouvae Lameere, 1884, Merobruchus bicoloripes (Pic, 1930) and Stator limbatus (Horn, 1873). In the fruits of E. timbouva, only one species was found (S. limbatus). E. contortisiliquum seed consumption was proportionately higher (55.2%) to that of E. timbouva (15%). The germination of predated seeds from E. contortisiliquum was null, whereas 40% of predated seeds from E. timbouva germinated.
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We evaluated the accuracy of skinfold thicknesses, BMI and waist circumference for the prediction of percentage body fat (PBF) in a representative sample of 372 Swiss children aged 6-13 years. PBF was measured using dual-energy X-ray absorptiometry. On the basis of a preliminary bootstrap selection of predictors, seven regression models were evaluated. All models included sex, age and pubertal stage plus one of the following predictors: (1) log-transformed triceps skinfold (logTSF); (2) logTSF and waist circumference; (3) log-transformed sum of triceps and subscapular skinfolds (logSF2); (4) log-transformed sum of triceps, biceps, subscapular and supra-iliac skinfolds (logSF4); (5) BMI; (6) waist circumference; (7) BMI and waist circumference. The adjusted determination coefficient (R² adj) and the root mean squared error (RMSE; kg) were calculated for each model. LogSF4 (R² adj 0.85; RMSE 2.35) and logSF2 (R² adj 0.82; RMSE 2.54) were similarly accurate at predicting PBF and superior to logTSF (R² adj 0.75; RMSE 3.02), logTSF combined with waist circumference (R² adj 0.78; RMSE 2.85), BMI (R² adj 0.62; RMSE 3.73), waist circumference (R² adj 0.58; RMSE 3.89), and BMI combined with waist circumference (R² adj 0.63; RMSE 3.66) (P < 0.001 for all values of R² adj). The finding that logSF4 was only modestly superior to logSF2 and that logTSF was better than BMI and waist circumference at predicting PBF has important implications for paediatric epidemiological studies aimed at disentangling the effect of body fat on health outcomes.
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Phytochromes phyB and phyA mediate a remarkable developmental switch whereby, early upon seed imbibition, canopy light prevents phyB-dependent germination, whereas later on, it stimulates phyA-dependent germination. Using a seed coat bedding assay where the growth of dissected embryos is monitored under the influence of dissected endosperm, allowing combinatorial use of mutant embryos and endosperm, we show that canopy light specifically inactivates phyB activity in the endosperm to override phyA-dependent signaling in the embryo. This interference involves abscisic acid (ABA) release from the endosperm and distinct spatial activities of phytochrome signaling components. Under the canopy, endospermic ABA opposes phyA signaling through the transcription factor (TF) ABI5, which shares with the TF PIF1 several target genes that negatively regulate germination in the embryo. ABI5 enhances the expression of phytochrome signaling genes PIF1, SOMNUS, GAI, and RGA, but also of ABA and gibberellic acid (GA) metabolic genes. Over time, weaker ABA-dependent responses eventually enable phyA-dependent germination, a distinct type of germination driven solely by embryonic growth.
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Summary
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Selostus: Ruokohelven siementuotanto-ominaisuudet ja itävyys Suomessa
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Spore germination in Rhizopogon abietis, R. luteolus, R. roseolus and R. villosulus was induced in the presence of Rhodotorula glutinis and activated charcoal, in agar medium (N6:5). In one R. roseolus sample, 51% of spores germinated within 35 days, allowing observation of the course of spore germination and the different developmental patterns of homokaryotic mycelia. In these plates, spores showed two times of germination. The spores that germinated early produced an apical germ tube. Later other spores germinated in proximity to young mycelium, by forming a germ vesicle. One of the hyphal growth patterns obtained (interruption-swelling-ramification) is similar to that reported for other fungi. With this technique for inducing spore germination, it is possible to obtain enough monosporic cultures to perform mating tests. Key words: Basidiomycotina, Hypogeous, Monosporic Cultures.
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Emergence and stand establishment of tomato (Lycopersicon lycopersicum (L.) (Karsten ex Farw) and pepper (Capsicum annus L.) seeds are often slow and erratic, particularly under stress conditions. Field emergence trials sometimes have not responded to priming in pepper. This study examined the combined effects of matriconditioning and gibberellin application on the germination and stand establishment of pepper and tomato seeds. Pepper and tomato seeds were conditioned with a solid carrier, Micro Cel E, in the presence of gibberellic acid (GA) for 1, 2 , 3 and 4 days at 15 and 25ºC. The results showed that, in all cases, even under stress conditions, the combination of matriconditioning with GA was effective in improving germination and emergence of pepper and tomato. The germination time was, in average, reduced by 2 to 3 days by primed seeds. Thus, matriconditioning, during which germination is suspended, provides an unique means to rapidly and efficiently digest the endosperm by GA-induced enzymes and reduce the mechanical restraints of endosperm thus providing energy to start and sustain embryo growth.