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| Registros recuperados: 14 | |
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| Amaral,Adriana; Takaki,Massanori. |
| The germination of achenes of Bidens pilosa L. was analyzed during the life span of the mother plant. Decrease in the range of achene size was monitored until the senescence of the mother plant when the shortest achenes were harvested. The analysis of the germination percentage confirmed the presence of two distinct classes, formerly defined as short and long ones. Because length can not be used for the separation of those classes, the morphological characteristics of the tegument, specially of the ornament must be used for separation of the achenes with verrucose tegument (formerly named as short achenes) and achenes without ornament of the tegument (formerly named as long achenes). The achenes with verrucose tegument presented dormancy and light... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bidens pilosa; Seed dimorphism; Phytochrome; Seed germination. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131998000100002 |
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| Simão,Edson; Takaki,Massanori. |
| The effect of light and temperature on Tibouchina mutabilis seed germination was analyzed by isothermic incubations in the range of 10 to 40 °C, with 5 °C intervals under both continuous white light (32.85 µmolm-2s-1) and darkness and alternating temperatures (15-20; 15-25; 15-30; 15-35; 20-25; 20-30; 20-35; 25-30; 25-35 and 30-35 °C) under both photoperiod of 12 hours and continuous darkness. The seeds of T. mutabilis need light to trigger the germination and no germination was observed in darkness. The range of optimum temperatures for germination was between 25 to 30 °C and the 20-25 °C alternating temperatures. These results indicate that T. mutabilis behaves as a pioneer species and daily alternating temperatures did not change the light sensitivity... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Light; Phytochrome; Seed germination; Tibouchina. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032008000200006 |
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| SILVA,E.M.; PEREIRA,J.C.; FERREIRA,V.M.; SOUZA,R.C.. |
| ABSTRACT: The objective of the present work was to study the influence of temperature and light on germination of seeds of Stigmaphyllon blanchetii, popularly known as rat tail. The first stage of the research evaluated the effect of three constant temperatures (20 oC, 25 oC and 30 oC) and an alternating temperature (20-30 oC). In the second stage, for simulation of different types of light, four conditions of luminosity (white, red, far red and absence of light) were used. The temperatures that provided the best germination and development for S. blanchetii are the constant (30 oC) and the alternating (20-30 oC) ones. The seeds germinated both in the presence and absence of light, but there was greater germination and seedling development in the absence... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Weed; Stigmaphyllon blanchetii; Photoblastism; Phytochrome. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100184 |
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| Tsegay,Berhanu A.; Lund,Leidulf; Nilsen,Jarle; Olsen,Jorunn E.; Molmann,Jorgen M.; Ernsten,Arild; Juntttila,Olavi. |
| The effect of Red light (R), Far-red light (FR) and R/FR combinations on shoot growth of latitudinal ecotypes of B. pendula was studied using special diodes that emit monochromatic lights. When a 12 hrs PAR (110 µmol m-2 s-1) was extended with R, FR or R/FR ratios, lower intensities of monochromatic lights could not prevent growth cessation. At 25 µmol m-2 s-1, FR compared to R enhanced stem elongation in all ecotypes. This was due to the inhibitive effect of R on internode elongation. When day-length was extended by R/FR at various ratios, there was continuous shoot elongation, but was found to be declining with increasing ratios. The more the R, the shorter were the internodes of each plant. B. pendula ecotypes produced branches when... |
| Tipo: Journal article |
Palavras-chave: Diode; Ecotype; Monochromatic; Photomorphogenesis; Phytochrome; Photosynthetically active radiation; PAR. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000100005 |
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| Bolige, Aoen; Goto, Ken. |
| Little is known about the photoreceptors involved in the photoperiodism of unicellular organisms, which we elucidated by deriving their action spectra. The flagellated alga Euglena gracilis exhibits photoperiodism, with a long-day response in cell reproduction. The underlying clock is a circadian rhythm with photoinductive capability, peaking at subjective dusk and occurring at the 26th hour in continuous darkness (DD) when transferred from continuous light (LL); it regulates photoinduction, a high-irradiance response (HIR), of a dark-capability of progressing through cell division. We derived the action spectra by irradiating E. gracilis with monochromatic light for 3 h at around the 26th hour; the action maxima occurred at 380, 450–460, 480, 610, 640,... |
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Palavras-chave: Cell division cycle; Complementary chromatic adaptation; Circadian; Euglena; End-of-day; Photoperiodism; Phytochrome; Shade avoidance. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/719 |
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| Quecini,Vera. |
| Studies employing model species have elucidated several aspects of photoperception and light signal transduction that control plant development. However, the information available for economically important crops is scarce. Citrus genome databases of expressed sequence tags (EST) were investigated in order to identify genes coding for functionally characterized proteins responsible for light-regulated developmental control in model plants. Approximately 176,200 EST sequences from 53 libraries were queried and all bona fide and putative photoreceptor gene families were found in citrus species. We have identified 53 orthologs for several families of transcriptional regulators and cytoplasmic proteins mediating photoreceptor-induced responses although some... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cryptochrome; Data mining; Light signaling; Phototropin; Phytochrome. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000500007 |
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| Bolige, Aoen; Goto, Ken. |
| Irradiance spectra change spatiotemporally, and angiosperms adapt accordingly, mainly through phytochromes. This study challenges the long-held belief that the flagellated alga Euglena gracilis lacks phytochromes and is therefore unaffected by spectral changes. We photoautotrophically cultured the alga under continuous light (LL), then transferred it to darkness. After about 26 h in darkness, different irradiations for 3 h enabled cell division in dark-arrested G2 cells evoking a high-irradiance response (HIR). The spectral characteristics of the irradiation during the LL period (pre-irradiation) defined the spectral sensitivity in the subsequent dark period. LL with light rich in the red spectrum led to a HIR to the red spectrum (R-HIR), whereas light... |
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Palavras-chave: Cell division; Circadian rhythms; End-of-day; Euglena; Photoperiodism; Phytochrome; Shade avoidance. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/720 |
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| Registros recuperados: 14 | |
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