Data/hora: 11/06/2024 06:21:49

Provedor de dados: 	39	
País: 	Brazil	
Título: 	Root growth and proton efflux rates of rice seedlings in a greenhouse environment	
Autores: 	França,Marcel Giovanni Costa; Rossiello,Roberto Oscar Pereyra; Ramos,Flávia Toledo; Zonta,Everaldo.	
Data: 	2006-03-01	
Ano: 	2006	
Palavras-chave: 	Root area; Fresh root mass; Relative growth rate; Acidification gradient.	
Resumo: 	Growth patterns and mean proton efflux rates (E H+) in roots of rice seedlings (Oryza sativa cv. IAC 47) grown under light conditions in a greenhouse environment were studied. Fifteen days after emergence, seedlings were transferred to pots containing 3.7 L of nutrient solution with 1.43 mmol NNH4+ L¹ as the sole source of nitrogen, to induce four sequential cycles of solution acidification, starting with a pH value of 5.3. Mean proton effluxes were computed based on growth periods of 48 h (from 0 to 192 h). E H+ values were estimated from values of relative root growth rates (RGR), expressed as root area (RA) or fresh mass (FM), and the linear coefficient of the regression of total free protons in nutrient solution (U H+) on RA or FM. Total free protons in the solution and the acidification gradients (deltaU H+/deltaMF) were better related to FM than to RA. Root growth rates were affected by photosynthetic irradiance and temperature fluctuations in the greenhouse, and were not clearly related to E H+ values. However, it was concluded that when a linear relation between U H+ and fresh root mass is found, E H+ estimates expressed by FM may be more reliable than when expressed by RA units.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062006000100003	
Editor: 	Sociedade Botânica do Brasil	
Relação: 	10.1590/S0102-33062006000100003	
Formato: 	text/html	
Fonte: 	Acta Botanica Brasilica  v.20 n.1 2006	
Fonte: 	info:eu-repo/semantics/openAccess