Data/hora: 17/06/2024 08:03:41

Biblioteca(s): | Embrapa Unidades Centrais.
Data corrente: | 01/08/1997
Data da última atualização: | 12/08/2019
Autoria: | USBERTI, R.; VALIO, I. F. M.
Afiliação: | ROBERTO USBERTI, Coordenadoria de Assistência Técnica Integral - CATI/Departamento de Sementes, Mudas e Matrizes; IVANY FERRAZ MARQUES VALIO, Universidade Estadual de Campinas - UNICAMP/Instituto de Biologia.
Título: | Endogenous growth regulator detection in Guinea grass seeds.
Ano de publicação: | 1997
Fonte/Imprenta: | Pesquisa Agropecuária Brasileira, Brasília, DF, v. 32, n. 7, p. 695-700, jul. 1997.
Idioma: | Inglês
Notas: | Título em português: Detecção de reguladores endógenos de crescimento em sementes de capim-colonião.
Conteúdo: | Endogenous growth regulator activity/levei was detected lii guinea grass (Panicum Inaximum Jacq.) seeds, a species widely used as a forage crop in the tropics, aiming at explaining its high seed dormancy levei. Seeds were previously scarified or not with suiphuric acid and osmoconditioned on PEG-6000. Endogenous growth regulators were detected as follow: gibberellin-like activity (growth of iettuce hypocotyi bioassay); cytokinins (increase of fresh mass of radish cotylcdon bioassay); ABA (spectrophotometer at 230 nm). Exogenous application of GA, showed a germination increasing effect while ABA had a complete effectivenessto prevent it. High-dormancy seed samples had higher gibbereilin-like actívity than low-dormancy ones and intact seeds showed higher gibberellin-like activity than scarified seeds; however, after osmoconditioning, opposite results were recorded. No significant activity of neutral promoters and cytokinins was detected. Average leveis of ABA for untreated, osmoconditioned after zero- and two-month-storage seed saznples were 0.51,0.39 and 0.21 mg. 100 kg 4, respectively. Chemical scarification did not alter either ABA leveis in high-dormancy seed samples (0.66 mg.l00 kg 4 ) or those of low-dormancy (0.23 mg. 100 kg'), lhe fornier being significantly higher than the latter. Finally, the results show that a gibberellin-ABA interaction appears to be the main factor accounting for dormancy, germination and osmoconditioning control in guinea grass seeds.
Palavras-Chave: | Osmocondicionamento; Osmoconditioning.
Thesagro: | Dormência; Germinação; Panicum Maximum.
Thesaurus Nal: | dormancy; germination.
Categoria do assunto: | --
URL: | http://ainfo.cnptia.embrapa.br/digital/bitstream/item/108662/1/ENDOGENOUS.pdf
Registro original: | Embrapa Unidades Centrais (AI-SEDE)
Exemplares: | AI-SEDE - (6291-1) - UPE - AP - PP - 630.72081 - P474 -  - DIS