Data/hora: 21/09/2024 15:43:17

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