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Germination of Senna Occidentalis link: seed at different osmotic potential levels

Delachiave,Maria Elena Aparecida; Pinho,Sheila Zambello de
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2003 EN
Relevância na Pesquisa
66.13%
The objective of this research was to study the effect of osmotic potential and salinity on the germination of seeds of Senna occidentalis, with and without a change of solutions. The percentage and rates of germination decreased according to decrease of potential, being more drastic when the substitutions of solutions were not made. The largest reductions were observed with the PEG solutions, with and without substitutions.

Impact of water potential on growth and germination of Fusarium solani soilborne pathogen of peanut

Palacios,Sofia; Casasnovas,Francisco; Ramirez,María L.; Reynoso,María. M.; Torres,Adriana M.
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 EN
Relevância na Pesquisa
46.31%
Studies were conducted to determine the effect of osmotic and matric stress on germination and growth of two Fusarium solani strains, the etiological agent responsible of peanut brown root rot. Both strains had similar osmotic and matric potential ranges that allowed growth, being the latter one narrower. F. solani showed the ability to grow down to -14 MPa at 25 °C in non-ionic modified osmotic medium, while under matric stress this was limited to -8.4 MPa at 25 °C. However, both strains were seen to respond differently to decreasing osmotic and matric potentials, during early stages of germination. One strain (RC 338) showed to be more sensitive to matric than osmotic (non ionic) and the other one (RC 386) showed to be more sensitive to osmotic than matric imposed water stress. After 24 h of incubation, both isolates behaved similarly. The minimum water potential for germination was -8.4 MPa on glycerol amended media and -5.6 MPa for NaCl and PEG amended media, respectively. The knowledge of the water potential range which allow mycelia growth and spore germination of F. solani provides an inside to the likely behaviour of this devastating soilborne plant pathogen in nature and has important practical implications.

Pollen treatment in high osmotic potential: a simple tool for in vitro preservation and manipulation of viability in gametophytic populations

Loguercio,Leandro Lopes
Fonte: Brazilian Journal of Plant Physiology Publicador: Brazilian Journal of Plant Physiology
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2002 EN
Relevância na Pesquisa
46.11%
A method for in vitro preservation and manipulation of pollen viability based on simple changes in osmotic potential (sucrose concentrations) in culture media was developed using tobacco pollen as the experimental model. High osmotic potentials were capable of reversibly inhibiting pollen germination, preserving its viability at room temperature for long periods, as assessed by subsequent incubation in germination medium. When pollen was pre-germinated for different periods and subsequently incubated in 80 % sucrose medium (inhibiting medium) there was a progressive decrease in its viability, which was a trend best described by a quadratic regression line. Nevertheless, very small variations in pollen-tube lengths and viable pollen grains more resistant to the pre-germination step were detected by this procedure. Consequences and potential applications of these findings were discussed for use in analyses of variability, selection in gametophytic populations and pollen storage.

Osmotic adjustment in roots and leaves of two sorghum genotypes under NaCl stress

Lacerda,Claudivan Feitosa de; Cambraia,José; Oliva,Marco Antonio; Ruiz,Hugo Alberto
Fonte: Brazilian Journal of Plant Physiology Publicador: Brazilian Journal of Plant Physiology
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2003 EN
Relevância na Pesquisa
46.08%
Seedlings of two sorghum genotypes [Sorghum bicolor (L.) Moench], one salt tolerant (CSF 20) and the other salt sensitive (CSF 18) were grown in nutrient solution containing 0, 50 and 100 mmol.L-1 NaCl for seven days and the osmotic potential (Ys) and the contribution of organic and inorganic solutes to the Ys were determined in the leaves and roots. Salinity reduced the Ys of the cellular sap of leaves and roots in both genotypes, mainly in the salt sensitive one. The higher decrease in the Ys in the salt sensitive genotype was mostly due to higher accumulation of Na+ and Cl- that probably exceeded the amount needed for the osmotic adjustment. Among the inorganic solutes, K+ contributed the most to the Ys in control unstressed seedlings, but its contribution decreased as salt stress increased, especially in the salt sensitive genotype. Soluble carbohydrates and amino acids were the organic solutes that contributed the most to the leaf and root Ys, respectively. No statistically significant difference in these organic solute contributions to the leaf Ys between genotypes was observed. Their contributions to the root Ys, however, were higher in the salt tolerant genotype, especially at higher NaCl concentration. Proline contribution to leaf and root Ys was quite small in both genotypes and its accumulation was not related to salt tolerance. Our results suggest that the salt tolerant genotype was able to maintain a more adequate osmotic pool in the leaves and roots under salt stress than the salt sensitive genotype.

Chloroplast Response to Low Leaf Water Potentials: II. Role of Osmotic Potential 1

Potter, J. R.; Boyer, J. S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1973 EN
Relevância na Pesquisa
46.25%
Electron transport in chloroplasts isolated from desiccated sunflower (Helianthus annuus L. cv. Russian Mammoth) leaves was compared with electron transport in sunflower chloroplasts in sorbitol-containing media having various osmotic potentials. In media having low osmotic potentials and dichloroindophenol as electron acceptor, the activity for electron transport was inhibited, but the inhibition was much less than that due to comparable desiccation in vivo. The inhibition at low osmotic potentials was rapidly reversed by returning the chloroplasts to media having high osmotic potentials, but the activity of chloroplasts from desiccated tissue showed no reversal when the chloroplasts were placed in media having high osmotic potentials. Nevertheless, the inhibition of chloroplast activity due to desiccation in vivo was basically reversible, because chloroplasts recovered quickly when they were rehydrated in vivo. The large differences between desiccation in vivo and exposure to low osmotic potential in vivo indicate that osmotic solutions did not reproduce the effects of tissue desiccation. It is concluded that decreases in the Gibbs free energy of water due to decreased osmotic potentials probably have only a small effect on electron transport in chloroplasts from desiccated tissue and do not account for the major effects of leaf desiccation on electron transport.

Reduced Osmotic Potential Effects on Photosynthesis 1: Identification of Stromal Acidification as a Mediating Factor

Berkowitz, Gerald A.; Gibbs, Martin
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1983 EN
Relevância na Pesquisa
46.11%
Addition of sorbitol, which facilitated reductions in reaction medium osmotic potential from standard (0.33 molar sorbitol, −10 bars) isotonic conditions to a stress level of 0.67 molar sorbitol (−20 bars), inhibited the photosynthetic capacity of isolated spinach (Spinacia oleracea) chloroplasts. This inhibition, which ranged from 64 to 74% under otherwise standard reaction conditions, was dependent on reaction medium inorganic phosphate concentration, with the phosphate optimum for photosynthesis reduced to 0.05 millimolar at the low osmotic potential stress treatment from a value of 0.25 millimolar under control conditions.

Reduced Osmotic Potential Inhibition of Photosynthesis 1: Site-Specific Effects of Osmotically Induced Stromal Acidification

Berkowitz, Gerald A.; Gibbs, Martin
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1983 EN
Relevância na Pesquisa
46.19%
The effects of reduced reaction medium osmotic potential (0.67 molar sorbitol as compared to a control treatment with 0.33 molar sorbitol) on the enzymic steps of the photosynthetic carbon reduction cycle were investigated using isolated spinach (Spinacia oleracea L. var Longstanding Bloomsdale) chloroplasts. Reversal of reduced osmotic potential inhibition of photosynthetic rates by a stromal alkalating agent (NH4Cl) was associated with specific steps of the cycle. Low osmotic potential induced stromal acidification was found to be facilitated by osmotically induced chloroplast shrinkage. However, the action of the alkalating agent was found not to be associated with reversal of osmotically induced morphological changes of the stromal compartment.

The Effect of Low Osmotic Potential on Nitrite Reduction in Intact Spinach Chloroplasts 1

Behrens, Paul W.; Xu, Fujuan; Werner, Marisa; Hoffman, Teresa; Marsho, Thomas V.; MacKay, A. Bryan
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1985 EN
Relevância na Pesquisa
46.19%
The effect of water stress (reduced osmotic potential) on photosynthetic nitrite reduction was investigated using intact, isolated spinach (Spinacia oleracea) chloroplasts. Nitrite-dependent O2 evolution was inhibited 39% at −29.5 bars osmotic potential, relative to a control at −11 bars. In the presence of an uncoupler of photophosphorylation this inhibition was not seen. Reduced osmotic potential did not inhibit either methyl viologen reduction or photosynthetic O2 reduction. These results indicate that an inhibition of electron transport to ferredoxin cannot account for the observed inhibition of nitrite-dependent O2 evolution. In vitro assay of nitrite reductase activity showed that the interaction of the enzyme with nitrite was not affected by changes in the concentrations of ions or molecules that might be caused by water stress conditions. These results indicate that the most likely site for the effect of water stress on chloroplastic nitrite reduction is the interaction of ferredoxin with nitrite reductase.

Osmotic Adjustment in Sorghum: I. Mechanisms of Diurnal Osmotic Potential Changes

Girma, Fekade S.; Krieg, Daniel R.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1992 EN
Relevância na Pesquisa
46.23%
Osmotic adjustment, defined as a lowering of osmotic potential (ψπ) due to net solute accumulation in response to water stress, has been considered to be a beneficial drought tolerance mechanism in some crop species. The objective of this experiment was to determine the relative contribution of passive versus active mechanisms involved in diurnal ψπ changes in sorghum (Sorghum bicolor L. Moench) leaf tissue in response to water stress. A single sorghum hybrid (cv AT×623 × RT×430) was grown in the field under variable water supplies. Water potential, ψπ, and relative water content were measured diurnally on expanding and the uppermost fully expanded leaves before flowering and on fully expanded leaves during the grain-filling period. Diurnal changes in total osmotic potential (Δψπ) in response to water stress was 1.1 megapascals before flowering and 1.4 megapascals during grain filling in comparison with 0.53 megapascal under well-watered conditions. Under water-stressed conditions, passive concentration of solutes associated with dehydration accounted for 50% (0.55 megapascal) of the diurnal Δψπ before flowering and 47% (0.66 megapascal) of the change during grain filling. Net solute accumulation accounted for 42% (0.46 megapascal) of the diurnal Δψπ before flowering and 45% (0.63 megapascal) of the change during grain filling in water-stressed leaves. The relative contribution of changes in nonosmotic volume (decreased turgid weight/dry weight) to diurnal Δψπ was less than 8% at either growth stages. Water stress did not affect leaf tissue elasticity or partitioning of water between the symplasm and apoplasm.

Relationship between Water Content and Osmotic Potential of Lentinula edodes

Koo, Chang-Duck; Cho, Sun-Young
Fonte: The Korean Society of Mycology Publicador: The Korean Society of Mycology
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.33%
This study was conducted to understand how osmotic potentials in Lentinula edodes tissues are related to water contents and how they change while a mushroom matures. Water content and osmotic potential of L. edodes mushroom tissues from log cultivation and sawdust cultivation were measured and the relationships were analyzed. Osmotic potentials in the tissues were exponentially proportional to their moisture contents and there were strain differences in the potentials. Strain 290 has lower osmotic potential than strain 302, in the tissues at the same water content. As the mushrooms mature, tissue water content maintained ca 94% in head tissues and ca 90% in gills, but significantly decreased from ca 90% to 82% in the stipe tissues. Osmotic potential changes were similar to the tissue water content changes as the mushrooms mature. While osmotic potentials maintained -0.25 to -0.45 MPa in head and gill tissues, the potentials greatly decreased from -0.65 to -1.33MPa in stipe tissues. Our results show that osmotic potentials in L. edodes tissues are exponentially proportional to tissue water contents, that strains differ in osmotic potential related to water, and that stipe tissues can still have nutritional value when they mature.

Formation of ovarian follicular fluid may be due to the osmotic potential of large glycosaminoglycans and proteoglycans

Clarke, H.; Hope, S.; Byers, S.; Rodgers, R.
Fonte: Bio Scientifica Ltd Publicador: Bio Scientifica Ltd
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
Relevância na Pesquisa
46.19%
During mammalian follicle development, a fluid-filled antrum develops in the avascular centre of the follicle. We investigated the hypothesis that follicular fluid contains osmotically-active molecules, sufficiently large so as to not freely escape the follicular fluid. Such molecules could generate an osmotic differential and thus recruit fluid from the surrounding vascularised stroma into the antrum. Follicular fluid was collected from bovine follicles classified histologically as healthy (n = 4 pools) or atretic (n = 4 pools). Dialysis of the follicular fluid at 300 kDa or 500 kDa resulted in a reduction in colloid osmotic pressure of 35% and 60%, respectively, in fluid from healthy follicles and 29% and 80% from atretic follicles. Digestion of follicular fluid with Streptomyces hyaluronidase, chondroitinase ABC or DNase 1 followed by dialysis resulted in reductions in osmotic pressure of 43%, 53% and 43% respectively for fluids from healthy follicles and 34%, 20% and 31% for atretic follicles. Digestion with collagenase I, proteinase K, heparanase 1 or keratanase had no significant effect on the osmotic pressure of follicular fluid of healthy follicles. Ion exchange and size exclusion, Western blotting and ELISA identified the proteoglycans versican and inter-alpha trypsin inhibitor and the glycosaminoglycan hyaluronan in follicular fluid. We conclude that these molecules or aggregates of them are of sufficient size to contribute to the osmotic potential of follicular fluid and thus recruit fluid into the follicular antrum. DNA may also contribute but it is probably not a component that is regulated for this role.; Hannah G Clarke...

Factors affecting seed germination of annual sowthistle (Sonchus oleraceus) in southern Australia

Chauhan, B.; Gill, G.; Preston, C.
Fonte: Weed Sci Soc Amer Publicador: Weed Sci Soc Amer
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
Relevância na Pesquisa
46.11%
Annual sowthistle has become more abundant under no-till systems in southern Australia. Increased knowledge of germination biology of annual sowthistle would facilitate development of effective weed control programs. The effects of environmental factors on germination and emergence of annual sowthistle seeds were examined in laboratory and field experiments. Seeds of annual sowthistle were able to germinate over a broad range of temperatures (25/15, 20/12, and 15/9 C day/night temperatures). Seed germination was favored by light; however, some germination occurred in the dark as well. Greater than 90% of seeds germinated at a low level of salinity (40 mM NaCl), and some seeds germinated even at 160 mM NaCl (7.5%). Germination decreased from 95% to 11% as osmotic potential increased from 0 to −0.6 MPa and was completely inhibited at osmotic potential greater than −0.6 MPa. Seed germination was greater than 90% over a pH range of 5 to 8, but declined to 77% at pH 10. Seedling emergence was the greatest (77%) for seeds present on the soil surface but declined with depth, and no seedlings emerged from a soil depth of 5 cm. In another experiment in which seeds were after-ripened at different depths in a field, seed decay was greater on the soil surface than at 2 or 5 cm depth. At the end of the growing season...

Soil microbial activity and community structure as affected by osmotic and matric potential.

Chowdhury, Nasrin
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2011
Relevância na Pesquisa
46.48%
Salinization of soils is a serious land degradation problem, causing poor plant growth and low microbial activity due to osmotic stress, ion toxicity and imbalanced element uptake. In arid, semi arid or seasonally arid (Mediterranean) regions, low or fluctuating matric potential causes further stress to soil microorganisms in saline soil by decreasing the osmotic potential as salts in the soil solution become more concentrated, as well as by reducing diffusion and thus substrate availability. Soil properties such as soil texture, water retention characteristics and organic matter content also influence soil microbial activity and community structure and the effect of salinity and matric potential on soil microorganisms. While the effects of low matric and low osmotic potential on soil microorganisms have been studied separately, little is known about their interaction. The objective of this thesis was to determine the interaction between soil matric and osmotic potential on soil microbial activity and community structure. Most experiments described in this thesis were carried out with two non-saline soils (sand and sandy loam) differing in nutrient status, microbial biomass and community composition. Osmotic stress was induced by application of different rates of NaCl. In all experiments...

Carbon mineralization in saline soils as affected by residue composition and water potential

Setia, R.; Marschner, P.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
46.33%
In saline soils under semi-arid climate, low matric and osmotic potential are the main stressors for microbes. But little is known about the impact of water potential (sum of matric and osmotic potential) and substrate composition on microbial activity and biomass in field collected saline soils. Three sandy loam soils with electrical conductivity of the saturated soil extract (ECe) 3.8, 11 and 21 dS m−1 (hereafter referred to EC3.8, EC11 and EC21) were kept at optimal water content for 14 days. After this pre-incubation, the soils were either left at optimal water content or dried to achieve water potentials of −2.33, −2.82, −3.04 and −4.04 MPa. Then, the soils were amended with 20 gkg−1 pea or wheat residue to increase nutrient supply. Carbon dioxide emission was measured over 14 days; microbial biomass C was measured at the end of the experiment. Cumulative respiration decreased with decreasing water potential and was significantly (P<0.05) lower in soils at water potential −4 MPa than in soils at optimal water content. The effect of residue type on the response of cumulative respiration was inconsistent; with residue type having no effect in the saline soils (EC11 and EC21) whereas in the non-saline soil (EC3.8), the decrease in respiration with decreasing water potential was less with wheat than with pea residue. At a given water potential...

Role of Osmotic Potential Gradients during Water Stress and Leaf Senescence in Fragaria virginiana1

O'Neill, Sharman D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1983 EN
Relevância na Pesquisa
46.26%
The physiological basis underlying differences in sensitivity of different aged leaves to water stress was investigated in Fragaria virginiana Duchesne. Differential susceptibility of only older leaves to water stress in the field during summer months appeared related to gradients in leaf osmotic potential within the plant and by an age dependency in the ability of leaves to adjust osmotically when challenged by periodic water deficits. Under greenhouse conditions, older leaves senesced invariably during an imposed water stress while control leaves of comparable age and stressed younger leaves remained green. Osmotic potentials of intermediate aged and younger leaves became approximately 1 to 2 bars lower after a single cycle of imposed stress and up to 10 bars lower after two cycles of stress. Pronounced gradients in leaf osmotic potential within individual whole plants were observed following two cycles of water stress that were significantly different from control values. Osmotic adjustment was dependent on leaf age with the greatest capacity for adjustment in the intermediate aged leaves. Loss of osmotic adjustment was rapid upon rewatering with a half-life of 4 days. An irreversible component of adjustment was observed, amounting to about 10% (or 2 bars) of the maximally adjusted state. This irreversible component could be accounted for in part by significant changes in cell size and other anatomical alterations in the leaf that affect cellular osmotic volume...

Dissecting the effects of nitrate, sucrose and osmotic potential on Arabidopsis root and shoot system growth in laboratory assays

Roycewicz, Peter; Malamy, Jocelyn E.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 05/06/2012 EN
Relevância na Pesquisa
46.23%
Studying the specific effects of water and nutrients on plant development is difficult because changes in a single component can often trigger multiple response pathways. Such confounding issues are prevalent in commonly used laboratory assays. For example, increasing the nitrate concentration in growth media alters both nitrate availability and osmotic potential. In addition, it was recently shown that a change in the osmotic potential of media alters the plant's ability to take up other nutrients such as sucrose. It can also be difficult to identify the initial target tissue of a particular environmental cue because there are correlated changes in development of many organs. These growth changes may be coordinately regulated, or changes in development of one organ may trigger changes in development of another organ as a secondary effect. All these complexities make analyses of plant responses to environmental factors difficult to interpret. Here, we review the literature on the effects of nitrate, sucrose and water availability on root system growth and discuss the mechanisms underlying these effects. We then present experiments that examine the impact of nitrate, sucrose and water on root and shoot system growth in culture using an approach that holds all variables constant except the one under analysis. We found that while all three factors also alter root system size...

Study of the involvement of H+-ATPase and osmotic adjustment in the resistance of Catharanthus roseus suspension cells to salt stress

Elkahoui, Salem; Carvajal, Micaela; Ghrir, Rachid; Limam, Férid
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
Relevância na Pesquisa
56.16%
The salt-induced H+-ATPase activity and osmotic adjustment responses of Catharanthus roseus (L.) G. Don suspension cultures were studied. Cells were treated with 0, 50 or 100mM NaCl for 7days or were maintained for 8 months with 50 mM NaCl (50T cells). Growth, osmotic potential (), ions content, soluble sugars, proline and total amino acids were determined in the sap of control and salt-treated cells. Salinity reduced cell growth and . The higher decrease in the in salt-treated cells was due to higher accumulation of Na+ and Cl–. The levels of organic solutes, such as soluble sugars, free proline and total amino acids, increased with salt treatment. These results suggest that salt-tolerant cells are able to osmotically adjust. Salinity treatments stimulated H+-ATPase activity. Immunodetection of the enzyme showed that the increased activity was due to an increased amount of protein in the plasmalemma. The induction by NaCl, especially at 100 mM NaCl and for 50T cells, could account for the K+ and Cl– uptake but not for higher or lower tolerance.; The Secretariat of State for Scientific Research and Technology from Tunisia is gratefully acknowledged for supporting this research.; Peer reviewed

Efeito de reguladores de crescimento no potencial osmótico de tomateiro (Lycopersicon esculentum Mill. cv. Angela); Effects of growth regulators on osmotic potential of tomato (Lycopersicon esculentum cv. Angela)

Castro, Paulo R.C.; Duarte, Maria L.R.; Machado, Carlos C.; Castro, Carlos; Brito, Antonio S.
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; Formato: application/pdf
Publicado em 01/01/1977 POR
Relevância na Pesquisa
46.31%
A importância do estudo do potencial osmótico das plantas deve-se ao fato deste parâmetro ser considerado o principal componente do potencial hídrico, refletindo o equilíbrio de água na planta. Determinou-se o potencial osmótico foliar do tomateiro (Lycopersicon esculentum Mill. cv. "Angela") através de osmômetro de precisão. As plantas haviam sido tratadas com cloreto de (2-cloroetil) trimetilamônio (CCC) 2000 ppm, ácido succínico-2,2-dimetilhidrazida (Alar) 3000 ppm e giberelato de potássio (Gibrel) 100 ppm, além do controle. Verificou-se que o Gibrel promoveu uma redução no potencial osmótico; sendo que Alar provocou flutuações no potencial do tomateiro "Angela". O CCC causou maior equilíbrio no potencial osmótico foliar do tomateiro. Observou-se que as folhas da cultivar "Angela'' mostraram potencial osmótico mais alto pela manhã com relação ao período da tarde.; This research deals with the effects of exogenous growth regulators on leaf osmotic potential of tomato cultivar "Angela". To study the influence of growth substances on osmotic potentia, (2-chloroethyl) trimethylammonium chloride (CCC) at concentration of 2,000 ppm, succinic acid-2,2-dirnethylhydrazide (Alar) (3,000 ppm), and potassium gibberellate (Gibrel) (100 ppm) were applied. The leaf osmotic potential established everyday during six days showed that plants treated with Gibrel presented lower (negative) osmotic potential. CCC promoted better equilibrium in the osmotic potential of tomato plants. Leaves of tomato cultivar "Angela" presented higher osmotic potential in the morning in relation to leaves collected in the afternoon.

Ação de fitoreguladores no potencial osmótico da soja (Glycine max cv. Davis); Action of growth regulators on osmotic potential of soybean (Glycine max cv. Davis)

Castro, Paulo R.C.
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 01/01/1980 POR
Relevância na Pesquisa
46.25%
Determinou-se em condições de casa de vegetação o efeito de fitoreguladores no potencial osmótico foliar da soja. As aplicações das substâncias de crescimento foram realizadas 21 dias após a semeadura. Efetuou-se pulverização de cloreto (2 -cloroetil) trimetilamônio (CCC) 2.000 ppm, ácido succínico-2,2-dimetilhidrazida (SADH) 4.000 ppm, ácido giberélico (GA) 100 ppm, ácido indolilacético (IAA) 100 ppm, além do controle. O potencial osmótico foliar foi determinado durante três dias em intervalos de 24 horas. Utilizou-se o delineamento inteiramente casualizado com 4 repetições e procedeu-se à comparação de médias pelo teste Tukey (57o). Os resultados obtidos pelo método osmométrico mostraram que plantas tratadas com fitoreguladores apresentam variação no potencial osmótico foliar dependendo da disponibilidade hídrica do substrato. Aplicação de SADH reduziu o potencial osmótico da soja 'Davis'.; This research deals with the effects of exogenous growth regulators on leaf osmotic potential of 'Davis' soybean. To study the influence of growth substances on osmotic potential (2-chloroethyl) trimethylammonium chloride (CCC) at concentration of 2,000 ppm, succinic acid-2,2-dimethylhydra-zide (SADH) 4,000 ppm...

GERMINATION, SEED VIGOR AND SEEDLING GROWTH OF CORN ON HIDRIC STRESS CONDITIONS; GERMINAÇÃO, VIGOR DE SEMENTES E CRESCIMENTO DE PLÂNTULAS DE MILHO SOB CONDIÇÕES DE DÉFICIT HÍDRICO

KAPPES, Claudinei; Universidade Estadual Paulista Júlio de Mesquita Filho; ANDRADE, João Antônio da Costa; Universidade Estadual Paulista Júlio de Mesquita Filho; HAGA, Kuniko Iwamoto; Universidade Estadual Paulista Júlio de Mesquita Filho; FERREIRA,
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 23/12/2009 ENG
Relevância na Pesquisa
46.21%
The water availability and movement of water to the seeds are important for germination and seedling emergence, and these factors are influenced by soil water potential. Thus, this study was evaluated the germination, seed vigor and seedling growth of corn (XB 6010, XB 6012, XB 9003 and AG 9010) submited to hidric stress conditions. The seeds were sowing in paper towels moistened with mannitol solutions, using five levels of osmotic potential: 0.0 (control), -0.3, -0.6, -0.9 and -1.2 MPa. We evaluated the first count, and rate of germination, primary root length and shoot for shoot/root and fresh weight of seedlings. The average of hybrids were compared by Tukey test (P<0.05) and the mean levels of osmotic potential by regression analysis. Except for biomass of the seedling, there was an interaction between the factors for all tests, showing that the hybrids had a distinct behavior between them in relation to water stress induced by mannitol. Drought causes a reduction in the performance of hybrid seed corn, and they have behaved differently from each other as the tolerance in this condition. A reduction of germination, seed vigor and growth of maize seedlings as the osmotic potential of water becomes more negative; A disponibilidade hídrica e o movimento de água para as sementes são importantes para a germinação e emergência das plântulas...