SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Villela,F. A..

The water relations play a fundamental role in seed biology. Thus, the purpose of the present paper was to analyze the performance of water status in seed development and germination. The researches have suggested that the water potential of the seed or seed structures provides a better indicator of the seed water status than water content. The seed water status plays a regulatory role in seed development and germination.

Relações hídricas em espécies lenhosas no campus Pampulha/UFMG, Belo Horizonte, MG

Palavras-chave: Water status; Hydration levels; Water potential.

Ano: 1998

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161998000500018

Rev. Bras. Bot.

SILVA,BRUNO GUSMÃO; LEMOS FILHO,JOSÉ PIRES DE.

O presente trabalho objetivou avaliar as relações hídricas em função da demanda evaporativa e da densidade da madeira em Swietenia macrophylla King, Joannesia princeps Vell., Inga edulis Mart., Licania tomentosa (Benth.) Fritsch e Centrolobium tomentosum Guill. ex Benth. O potencial hídrico foi determinado com uma câmara de pressão e a condutância estomática, com porômetro de difusão na estação chuvosa, na estação seca e nas situações transicionais. J. princeps foi a espécie que apresentou maiores valores de potencial hídrico no "predawn" (psiPD > - 0,25 Mpa), e I. edulis os menores valores (psiPD = - 1,5 MPa). J. princeps apresentou maiores valores de potencial hídrico durante o dia (psiMD > - 1,5 MPa), e os menores valores foram observados em S....

Contribuicao hidrica do cerrado para as grandes bacias hidrograficas brasileiras.

Palavras-chave: Water potential; Conductance; Vapour pressure deficit; Wood density.

Ano: 2001

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042001000500006

Infoteca-e

LIMA, J. E. F. W.; SILVA, E. M. da.

bitstream/CPAC-2009/24358/1/p2002_21.pdf

Tipo: Fôlder / Folheto / Cartilha (INFOTECA-E)

Palavras-chave: ECAGUA100; Brasil; Savanna.; Bacia Hidrográfica; Cerrado; Manejo de Água; Potencial Hídrico; Recurso Hídrico.; Brazil; Water potential; Water resources; Water management; Watersheds..

Ano: 2004

URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567621

Electrical conductivity and soybean seedling emergence

Colete,Julio Cesar Fachini; Vieira,Roberval Daiton; Dutra,Alek Sandro.

Evaluation of soybean [Glycine max (L.) Merrill] seeds vigor and its relation with field seedling emergence can provide secure indicatives of seed physiological potential. The present research studied the relationship between the electrical conductivity test and the seedling emergence of soybean in field and laboratory. The field experiment was sown in November 26th, December 3td and 10th, 2000. Laboratory tests were performed using levels of water potential in the substrate (soil) -0.03; -0.2; -0.4; and -0.6 MPa. Fourteen seed lots, seven of 'Embrapa 48' and seven of 'BRS 133' soybean cultivars were used. Laboratory tests comprised seed water content determination, before and after the accelerated aging; germination and vigor tests (accelerated aging and...

Water osmotic absorption in Coleus blumei plants under salinity stress

Palavras-chave: Glycine max; Seed analysis; Water content; Vigor; Water potential.

Ano: 2004

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000400006

BABT

Sena,José Ozinaldo Alves de; Zaidan,Humberto Actis; Castro,Paulo Roberto de Camargo e.

Three month old Coleus blumei plants in pots were treated with different NaCl concentrations: 0.00, 0.25, 0.50 and 1.00%. To determine the water osmotic absorption, the plants had their stems cut at 10 cm from the soil surface. The remaining stems were linked to glass tubes by flexible rubber tubes. Readings of the water column level in the glass tubes were performed at each 30 minutes, corresponding to the water osmotic absorption, with a total of eleven readings. Other Coleus blumei, with the same age, received the NaCl concentrations, and were evaluated under field conditions in terms of transpiration and stomatal resistance. A randomized complete block analysis was used with five replications. An increase of osmotic absorption was verified for all...

Procesos fisiológicos y contenido de polisacáridos estructurales en nopalito (Opuntia spp.) y su modificación por el potencial de agua del suelo

Palavras-chave: Water relations; Water potential; Transpiration; Stomatal resistance.

Ano: 2006

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000700001

Colegio de Postgraduados

García Ruiz, Mayra Teresa.

Se evaluaron los cambios de acidez titulable a lo largo de 24 h, de las yemas vegetativas con longitud media de 0.5 cm y nopalitos de 6 y 11 cm, de Opuntia ficus-indica de los cultivares Atlixco, Copena V1, Milpa Alta, Moradaza y Solferino, con riego. También se evaluó el efecto de la disminución del potencial de agua (ΨA) del suelo, por suspensión del riego durante 60 días, en condiciones de invernadero, en el potencial osmótico (ΨS ), liberación de electrolitos (o índice de daño membranal, Id) y contenido de polisacáridos estructurales de los nopalitos de esos cinco cultivares y una recolecta silvestre de O. streptacantha. La acidez de las yemas vegetativas y los nopalitos fluctuó entre 0.2 y 0.9 % a lo largo de las 24 horas del día, con las...

Tipo: Tesis

Palavras-chave: Acidez titulable; Potencial hídrico; Potencial osmótico; Polisacáridos; Maestría; Fisiología Vegetal; Tritable acidity; Water potential; Osmotic potential; Polysaccharides.

Ano: 2007

URL: http://hdl.handle.net/10521/1654

Water status and gas exchange of umbu plants (Spondias tuberosa Arr. Cam.) propagated by seeds and stem cuttings

Rev. Bras. Frutic.

Lima Filho,José Moacir Pinheiro.

The experiment was carried out at the Embrapa Semi-Árido, Petrolina-PE, Brazil, in order to study the physiological responses of umbu plants propagated by seeds and by stem cuttings under water stress conditions, based on leaf water potential and gas exchange measurements. Data were collected in one-year plants established in pots containing 30 kg of a sandy soil and submitted to twenty-day progressive soil water deficit. The evaluations were based on leaf water potential and gas exchange data collection using psychrometric chambers and a portable infra-red gas analyzer, respectively. Plants propagated by seeds maintained a significantly higher water potential, stomatal conductance, transpiration and photosynthesis under decreasing soil water availability....

Palavras-chave: Water potential; Stomatal conductance; Transpiration; Photosynthesis; Root tubers.

Ano: 2007

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452007000200032

Ecophysiology of tea

De Costa,W.A. Janendra M.; Mohotti,A. Janaki; Wijeratne,Madawala A..

Tea [Camellia sinensis (L.) O. Kuntze] is one of the most important beverage crops in the world. The major tea-growing regions of the world are South-East Asia and Eastern Africa where it is grown across a wide range of altitudes up to 2200 m a.s.l.. This paper reviews the key physiological processes responsible for yield determination of tea and discusses how these processes are influenced by genotypic and environmental factors. Yield formation of tea is discussed in terms of assimilate supply through photosynthesis and formation of harvestable sinks (i.e. shoots). The photosynthetic apparatus and partial processes (i.e. light capture, electron transport and carboxylation) of tea show specific adaptations to shade. Consequently, maximum light-saturated...

Ecophysiology of coconut palm under water stress

Palavras-chave: Climate change; Photoinhibition; Photosynthesis; Shoot growth; Temperature; Vapour pressure deficit; Water potential.

Ano: 2007

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400005

Gomes,Fábio P.; Prado,Carlos H.B.A..

Coconut palm is of great social and economic importance for millions of people in the tropics and subtropics. Drought is one of the main environmental factors that limit coconut productivity. In this review, physiological and morphological data are presented in an integrated perspective to provide a holistic view of the behavior of coconut trees facing water deficit under both field and controlled conditions. Great capacity to produce homorhizic roots capable of searching continuously for water and nutrients and high protoplasmic tolerance in leaves allows the coconut tree to endure water deficit. High membrane stability, osmoprotection, osmoregulation and enhanced activity of antioxidant enzymes are characteristics often found in leaves of...

Water relations and organic solutes production in four umbu tree (Spondias tuberosa) genotypes under intermittent drought

Palavras-chave: Cocus nucifera; Desiccation tolerance; Leaf gas exchange; Leaf water relations; Net photosynthesis; Osmotic potential; Water potential; Water-use efficiency.

Ano: 2007

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400008

Silva,Elizamar C.; Nogueira,Rejane J. M. C.; Vale,Fernando H. A.; Melo,Natoniel F. de; Araújo,Francisco P. de.

In order to evaluate changes in leaf water potential (ψw) and solute accumulation induced by intermittent drought, an research was performed under greenhouse conditions using four umbu tree genotypes (GBU 44, GBU 48, GBU 50 and GBU 68) and two water treatments (control and stressed by withholding water), with four replicates. The ψw was measured in four-hour intervals during a 24-hour period at the first stomatal closure and at the end of the experimental period. Carbohydrates, amino acids, protein and proline contents were also evaluated in leaves and roots. Significant differences were found in most of the studied parameters. The lower ψw hour was between 800 h and 1200 h. GBU 50 reduced significantly ψw in stressed plants at 800 h, while control plants...

Physiological responses and production of 'Syrah' vines as a function of training systems

Palavras-chave: Carbohydrates; Proline; Spondias tuberosa; Water potential.

Ano: 2009

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100006

Favero,Ana Carolina; Amorim,Daniel Angelucci de; Mota,Renata Vieira da; Souza,Claudia Rita de; Regina,Murillo de Albuquerque.

Plant architecture and its interaction with agricultural practices and environmental constraints is determinant for grapevine canopy structure, which is related to carbon assimilation, bud fertility and fruit quality. In this context, this study evaluated the performance of field-grown 'Syrah' grapevines conducted by two management systems: Vertical Shoot Position (VSP) or a modified Geneva Double Curtain (GDC), in Pirapora, state of Minas Gerais, Brazil, during the winters of 2007 and 2008. The evaluations of leaf area, water relations and net CO2 assimilation were made at the end of the ripening period. Yield per vine and per hectare were estimated and mean berry weight and diameter, total soluble solids, pH and titratable acidity were evaluated during...

Anatomical root variations in response to water deficit: wild and domesticated common bean (Phaseolus vulgaris L)

Palavras-chave: CO2 assimilation; Canopy management; Water potential; Berry temperature; Fruit quality.

Ano: 2010

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162010000300003

Biol. Res.

Peña-Valdivia,Cecilia B; Sánchez-Urdaneta,Adriana B; Meza Rangel,Joel; Juárez Muñoz,Juana; García-Nava,Rodolfo; Celis Velázquez,Raquel.

Root anatomical responses to water deficit are diverse and regulation of water uptake strongly depends on plant anatomy. The ancestors of common bean (Phaseolus vulgaris L.) cultivars are the wild common beans. Because wild beans adapt and survive well in theon atural environment, it is hypothesized that wild common bean roots are less affected than those of domesticated beans at low substrate water potential (ψW). A wild common bean accession from Chihuahua Mexico and cv. Bayomex were studied. Seedlings with a mean root length between 3 and 4 cm were maintained for 24 h in vermiculite at ψW of -0.03 (well hydrated), -0.65, -1.48 and -2.35 MPa (partially dry). Ten anatomical characteristics of differentiation and cell division in root...

Tipo: Journal article

Palavras-chave: Endodermis; Protoderm; Seedlings; Water potential; Xylem.

Ano: 2010

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000400006

Growth evaluation and water relations of Erythrina velutina seedlings in response to drought stress

Silva,Elizamar Ciríaco da; Silva,Marcos F. A.; Nogueira,Rejane J. M. C.; Albuquerque,Manoel B..

Erythrina velutina Willd. (common name: mulungu) is a deciduous, heliophyte found in the semi-arid region of northeastern Brazil. To evaluate the growth and water relations of mulungu seedlings in soils with different degrees of moisture content, an experiment was carried out under greenhouse conditions using four water treatments (100%, 75%, 50% and 25% of the field capacity- FC). Predawn (Ψpdw) and midday leaf water potential (Ψmdw), relative water content (RWC), plant height, number of leaves, stem diameter, leaf area (LA), specific leaf area (SLA), leaf area ratio (LAR), dry matter in different organs, biomass partitioning and root:shoot ratio were evaluated. No differences were detected between treatments for Ψpdw after 30 days; however, at midday,...

Analysis of Hydraulic Conductance Components in Field Grown, Mature Sweet Cherry Trees

Palavras-chave: Biomass allocation; Dry matter; Leaf area; Root to shoot ratio; Relative water content; Water potential.

Ano: 2010

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400002

Chilean J. Agric. Res.

Oyarzún,Ricardo; Stöckle,Claudio; Whiting,Matthew.

As a necessary step towards understanding soil water extraction and plant water relationships, the components of hydraulic conductance (K) of mature sweet cherry (Prunus avium L.) trees were evaluated in situ based on a Ohm´s law analog method. In June 2004, K was determined for 10-yr-old Bing/Gisela® 5 trees, from simultaneous measurements of whole canopy gas exchange and leaf (sunlit and shaded) and stem water potentials (Ψ). Leaf water potential of sunlit leaves was lower than shaded leaves, reaching minimum values of ca. -2.3 MPa around 14:00 h (solar time). Average total hydraulic conductance was 60 ± 6 mmol s-1 MPa-1, presenting a slight decreasing trend as the season progressed. The analysis of tree K components showed that it was...

Tipo: Journal article

Palavras-chave: Plant water relations; Transpiration; Water potential; Whole-canopy gas exchange.

Ano: 2010

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000100006

Mitigating effect of salicylic acid and nitrate on water relations and osmotic adjustment in maize, cv. Lluteño exposed to salinity

Ciencia e Investigación Agraria

Escobar,Hugo; Bustos,Richard; Fernández,Felipe; Cárcamo,Henry; Silva,Herman; Frank,Nicolás; Cardemil,Liliana.

We analyzed the mitigating effect of NO3 - and salicylic acid (SA) on the detrimental effects of salt stress by studying the water status of plants of maize grown in Hoagland's medium with NaCl 100 mM as the saline component, to which SA and NO3 - were added in different concentrations as mitigating agents. We evaluated water potential Ψw, osmotic potential Ψs, relative water content (RWC), turgor potential (Ψp ), and the osmotic adjustment (OA) of leaves and roots. SA 0.5 mM mitigated the effects of salinity by increasing the Ψw of the leaf, the Ψsof theroot, the Ψpof the leaf, RWC and OA of the leaf; while NO3 was only effective in combination with SA, mitigating the effects of salinity by increasing...

Tipo: Journal article

Palavras-chave: Nitrate; Osmotic potential; Osmotic adjustment; Salinity mitigation; Salicylic acid; Water potential; Water relative content.

Ano: 2010

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202010000300006

Germination of cotton cultivar seeds under water stress induced by polyethyleneglycol-6000

Meneses,Carlos Henrique Salvino Gadelha; Bruno,Riselane de Lucena Alcântara; Fernandes,Pedro Dantas; Pereira,Walter Esfrain; Lima,Leonardo Henrique Guedes de Morais; Lima,Marleide Magalhães de Andrade; Vidal,Márcia Soares.

The physiological quality of cotton cultivar seeds (Gossypium hirsutum var. latifolium L.) was evaluated in laboratory by the simulation of water potentials with polyethyleneglycol-6000 (0.0; -0.2; -0.4; -0.6; -0.8 and -1.0 MPa), at 25ºC using germitest paper as substrate. A completely randomized design in a 4 × 6 factorial scheme with four replications of 50 seeds each was used. The studied variables were: germination percentage, first count of germination, germination velocity index, accelerated aging in water, electrical conductivity, humidity, vigor classification, radicle length and radicle/shoot length ratio. The effect of water stress on seed viability and on plantlet vigor was severe at potentials below -0.4 MPa. The 'CNPA 187 8H' cultivar was the...