Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/100278
Type: Artigo de periódico
Title: Endogenous Growth Regulator Detection In Guinea Grass Seeds
Author: Usberti R.
Valio I.F.M.
Abstract: Endogenous growth regulator activity/level was detected in guinea grass (Panicum maximum Jacq.) seeds, a species widely used as a forage crop in the tropics, aiming at explaining its high seed dormancy level. Seeds were previously scarified or not with sulphuric acid and osmoconditioned on PEG-6000. Endogenous growth regulators were detected as follow: gibberellin-like activity (growth of lettuce hypocotyl bioassay); cytokinins (increase of fresh mass of radish cotyledon bioassay); ABA (spectrophotometer at 230 nm). Exogenous application of GA3 showed a germination increasing effect while ABA had a complete effectiveness to prevent it. High-dormancy seed samples had higher gibberellin-like activity 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 levels of ABA for untreated, osmoconditioned after zero- and two-month-storage seed samples were 0.51, 0.39 and 0.21 mg.100 kg-1, respectively. Chemical scarification did not alter either ABA levels in high-dormancy seed samples (0.66 mg.100 kg-1) or those of low-dormancy (0.23 mg.100 kg-1), the former 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.
Editor: 
Rights: aberto
Identifier DOI: 
Address: http://www.scopus.com/inward/record.url?eid=2-s2.0-0031494147&partnerID=40&md5=8f3720752366b38ade524bcc4d2f6c73
Date Issue: 1997
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File Description SizeFormat 
2-s2.0-0031494147.pdf277.66 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.