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Registro Completo |
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
14/12/1999 |
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Data da última atualização: |
14/12/1999 |
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Autoria: |
GOEDERT, C. O. |
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Título: |
Seed dormancy of tropical forage grasses and implications for the conservation of genetic resouces. |
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Ano de publicação: |
1984 |
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Fonte/Imprenta: |
Reading: University of Reading, 1984. |
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Páginas: |
190p. |
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Idioma: |
Inglês |
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Notas: |
PhD.Thesis. |
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Conteúdo: |
Investigations are described on the characteristics of tropical grass seeds which affect their management, particularly in genebanks. Five tropical forage grass species were selected for study - Brachiaria humidicola, Brachiaria decumbens, Panicum maximum, Paspalum guenoarum and Andropogon gayanus. It is shown that germination tests currently provide the best basis for monitoring viability. However two problems are particularly prevalent in tropical grasses which hinder the interpretation of germination tests: first, freshly harvested 'seeds' often show low purity (i.e. a high proportion of immature and empty spikelets); and secondly, many of the true seeds often show pronounced dormancy (i.e. though viable they are incapable of germination without special stimuli). Investigation of the purity problems showed that it can be overcome with the use of X-ray equipment, but other methods are unreliable. Investigation of the dormancy problem led to the conclusion that advantage needs to be taken of the interaction of several dormancy-breaking agents. It is shown that simultaneous use of three of these are specially valuable-alternating temperatures, light and nitrate ions. In particular it is important to define the optimum characteristics of alternating-temperature regimes for maximum stimulation of germination. Techniques for doing this were developed using a two-way temperature-gradient plate. Aplitude and thermoperiod were both shown to be particularly important attributes and, although the optima for each species investigated differed in detail, in no case did any optimum diverge far from a regime in which seeds were subjected to diurnal cycles of 20h at 15º and 4h at 35ºC in the presence of 10-2 M KNO3 and intermittent illumination. The significance of these and other experimental results are discused in relation to seed physiology and to problems of the management of seed accessions in genebanks for genetic conservation. MenosInvestigations are described on the characteristics of tropical grass seeds which affect their management, particularly in genebanks. Five tropical forage grass species were selected for study - Brachiaria humidicola, Brachiaria decumbens, Panicum maximum, Paspalum guenoarum and Andropogon gayanus. It is shown that germination tests currently provide the best basis for monitoring viability. However two problems are particularly prevalent in tropical grasses which hinder the interpretation of germination tests: first, freshly harvested 'seeds' often show low purity (i.e. a high proportion of immature and empty spikelets); and secondly, many of the true seeds often show pronounced dormancy (i.e. though viable they are incapable of germination without special stimuli). Investigation of the purity problems showed that it can be overcome with the use of X-ray equipment, but other methods are unreliable. Investigation of the dormancy problem led to the conclusion that advantage needs to be taken of the interaction of several dormancy-breaking agents. It is shown that simultaneous use of three of these are specially valuable-alternating temperatures, light and nitrate ions. In particular it is important to define the optimum characteristics of alternating-temperature regimes for maximum stimulation of germination. Techniques for doing this were developed using a two-way temperature-gradient plate. Aplitude and thermoperiod were both shown to be particularly important attributes and... Mostrar Tudo |
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Palavras-Chave: |
Feed grasses; Plant physiolofy; Rescurso genetico; Resource conservation; Tropical crops. |
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Thesagro: |
Dormência da Semente; Fisiologia Vegetal; Gramínea Tropical; Planta Forrageira. |
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Thesaurus Nal: |
dormancy; genetic resources; seeds. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02734nam a2200277 a 4500
001 1559470
005 1999-12-14
008 1984 bl uuuu m 00u1 u #d
100 1 $aGOEDERT, C. O.
245 $aSeed dormancy of tropical forage grasses and implications for the conservation of genetic resouces.
260 $aReading: University of Reading$c1984
300 $a190p.
500 $aPhD.Thesis.
520 $aInvestigations are described on the characteristics of tropical grass seeds which affect their management, particularly in genebanks. Five tropical forage grass species were selected for study - Brachiaria humidicola, Brachiaria decumbens, Panicum maximum, Paspalum guenoarum and Andropogon gayanus. It is shown that germination tests currently provide the best basis for monitoring viability. However two problems are particularly prevalent in tropical grasses which hinder the interpretation of germination tests: first, freshly harvested 'seeds' often show low purity (i.e. a high proportion of immature and empty spikelets); and secondly, many of the true seeds often show pronounced dormancy (i.e. though viable they are incapable of germination without special stimuli). Investigation of the purity problems showed that it can be overcome with the use of X-ray equipment, but other methods are unreliable. Investigation of the dormancy problem led to the conclusion that advantage needs to be taken of the interaction of several dormancy-breaking agents. It is shown that simultaneous use of three of these are specially valuable-alternating temperatures, light and nitrate ions. In particular it is important to define the optimum characteristics of alternating-temperature regimes for maximum stimulation of germination. Techniques for doing this were developed using a two-way temperature-gradient plate. Aplitude and thermoperiod were both shown to be particularly important attributes and, although the optima for each species investigated differed in detail, in no case did any optimum diverge far from a regime in which seeds were subjected to diurnal cycles of 20h at 15º and 4h at 35ºC in the presence of 10-2 M KNO3 and intermittent illumination. The significance of these and other experimental results are discused in relation to seed physiology and to problems of the management of seed accessions in genebanks for genetic conservation.
650 $adormancy
650 $agenetic resources
650 $aseeds
650 $aDormência da Semente
650 $aFisiologia Vegetal
650 $aGramínea Tropical
650 $aPlanta Forrageira
653 $aFeed grasses
653 $aPlant physiolofy
653 $aRescurso genetico
653 $aResource conservation
653 $aTropical crops
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Registro original: |
Embrapa Cerrados (CPAC) |
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Registro Completo
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Biblioteca(s): |
Embrapa Agroindústria Tropical. |
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Data corrente: |
30/04/2003 |
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Data da última atualização: |
18/08/2011 |
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Autoria: |
FREITAS, J. A. D. de; SOBRAL, L. F.; CRISOSTOMO, L. A.; LIMA, R. N. de; ROSSETTI, A. G.; MARTINS NETO, O. S. |
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Título: |
Desenvolvimento do coqueiro-anão verde em função de doses de N e K em fertirrigação: avaliação inicial. |
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Ano de publicação: |
2001 |
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Fonte/Imprenta: |
Fortaleza: Embrapa Agroindustria Tropical, 2001. |
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Páginas: |
4 p. |
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Série: |
(Embrapa Agroindustria Tropical. Pesquisa em Andamento, 81). |
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Idioma: |
Português |
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Palavras-Chave: |
Coqueiro-anao verde; Cultivo-coqueiro; Pesquisa-coqueiro. |
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Categoria do assunto: |
-- |
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URL: |
https://www.infoteca.cnptia.embrapa.br/infoteca/bitstream/doc/424416/1/Pa081.pdf
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Marc: |
LEADER 00714nam a2200217 a 4500
001 1424416
005 2011-08-18
008 2001 bl uuuu u0uu1 u #d
100 1 $aFREITAS, J. A. D. de
245 $aDesenvolvimento do coqueiro-anão verde em função de doses de N e K em fertirrigação$bavaliação inicial.
260 $aFortaleza: Embrapa Agroindustria Tropical$c2001
300 $a4 p.
490 $a(Embrapa Agroindustria Tropical. Pesquisa em Andamento, 81).
653 $aCoqueiro-anao verde
653 $aCultivo-coqueiro
653 $aPesquisa-coqueiro
700 1 $aSOBRAL, L. F.
700 1 $aCRISOSTOMO, L. A.
700 1 $aLIMA, R. N. de
700 1 $aROSSETTI, A. G.
700 1 $aMARTINS NETO, O. S.
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Embrapa Agroindústria Tropical (CNPAT) |
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