|
|
|
| Registros recuperados: 48 | |
|
|
| DA MATTA,FÁBIO M.; LOOS,RODOLFO A.; RODRIGUES,RODRIGO; BARROS,RAIMUNDO S.. |
| The actual (A) and potential (Apot) photosynthetic rates of C3 and C4 tropical crop species grown under greenhouse conditions was compared. The following species were investigated: Oryza sativa, Phaseolus vulgaris, Glycine max, Helianthus annuus, Gossypium hirsutum, Manihot esculenta, Theobroma cacao, Coffea arabica, Hevea brasiliensis, and Eucalyptus urophylla × E. grandis, all from the C3 group, and Amaranthus sp., Panicum maximum, Pennisetum purpureum, Zea mays and Saccharum officinarum, from the C4 group. A, determined under non-limiting light at ambient temperature and CO2, was measured with an infrared gas analyser, whilst Apot, determined under saturating light and CO2 at an optimal temperature (35 ºC for all species), was gauged with a gas-phase... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carbon assimilation rate; Photosynthetic oxygen evolution; Specific leaf area. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000100003 |
| |
|
|
| TAKAKI,MASSANORI. |
| The paper proposes the classification of seeds in relation to the forms of phytochrome instead of classical photoblastism. On the basis of published data all seeds have phytochrome and the term photoblastism should be replaced by forms of phytochrome that control germination: 1. Positive photoblastic seeds have phyB (and, to a lesser extent, phyD and phyE) controlling the germination process through Low Fluence Responses (LFR); 2. Negative photoblastic seeds have phyA controlling germination through High Irradiance Responses (HIR) and, when the pre-existing Pfr level is high enough to induce germination in darkness, through LFR by phyB; and 3. light insensitive seeds have phyA controlling germination through Very Low Fluence Responses (VLFR). |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Seed classification; Photoblastism; Phytochrome forms; Mode of action. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000100011 |
| |
|
| |
|
|
| CAMPOSTRINI,ELIEMAR; YAMANISHI,OSVALDO KIYOSHI. |
| Four papaya genotypes, two from the Solo group (Sunrise Solo TJ and Improved Sunrise Solo line 72/12) and two from the Formosa group (Tainung 02 and Know You 01) grown in ultisol under field conditions in Macaé, RJ, Brazil, were used in this study. Two different effective depths (ED) were determined in the area using a penetrographer with average soil moisture of 11.2%. The area with ED of 0.35 m with a maximum pressure of 4.12 MPa for penetration was defined as an area with restriction (WR) to root growth, while, the area with minimum ED of 0.60 m and a pressure lower than 2.30 MPa as an area with no restriction (NR). The net CO2 assimilation rate (A), stomatal conductance (g s), leaf temperature (Tl), intercellular partial pressure of CO2 (c i) and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carica papaya L.; Photosynthesis; Leaf temperature; Stomatal conductance; Intrinsic water use efficiency. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000200002 |
| |
|
|
| LACERDA,CLAUDIVAN FEITOSA DE; CAMBRAIA,JOSÉ; CANO,MARCO ANTONIO OLIVA; RUIZ,HUGO ALBERTO. |
| Seedlings of two sorghum (Sorghum bicolor (L.) Moench) genotypes with differential tolerance to salinity were exposed to 0 and 100 mM NaCl, gradually added in increments of 25 mM every 12 hours, in nutrient solution. Seven days after starting the salt treatment the growth of the shoot and root system and the inorganic and organic solutes contents were determined. Salinity reduced the dry matter yield and length of the shoot and root system in both sorghum genotypes, specially in the sensitive one. In general, it was observed an increase in Na+ and Cl- transfer to the shoot, in Na+ and Cl- accumulation and in the Na+/Cl- ratio but a decrease in the K+ and Ca2+ transfer to shoot and in the K+ and Ca2+ contents in the shoot, always with higher intensity in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Salinity; Salt stress; Salt accumulation; Organic solutes accumulation; Sorghum bicolor. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000300003 |
| |
|
| |
|
| |
|
|
| NAVES-BARBIERO,CHEILA CRISTINA; FRANCO,AUGUSTO CÉSAR; BUCCI,SANDRA JANET; GOLDSTEIN,GUILHERMO. |
| No presente estudo, comparou-se o curso diário de fluxo de seiva, condutância estomática e potencial hídrico (psi) de duas espécies sempre-verdes, Rapanea guianensis e Roupala montana. Os dados foram obtidos no final da estação seca, quando os efeitos do déficit hídrico seriam mais acentuados. As medidas foram realizadas no campo sujo, onde predomina gramíneas com sistemas radiculares superficiais, e no cerradão, em que a maior densidade de elementos lenhosos com sistemas radiculares profundos poderia levar a um esgotamento das reservas de água do subsolo na estação seca. Valores máximos de psinão diferiram para as duas espécies nas duas fisionomias estudadas. Os valores mínimos de potencial hídrico foliar de R. guianensis foram mais negativos (P<0,05)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rapanea guianensis; Roupala montana; Transpiração; Cerrado; Potencial hídrico. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312000000200003 |
| |
| Registros recuperados: 48 | |
|
|
|
