Resumos
Estudando-se a absorção do rádio fósforo por raízes destacadas das variedades IAC-164, 165 e 1246, Batatais, Caqui, Dourado precoce, 90 dias e Senbon (as primeiras nacionais, a última japonesa) verificou-se diferença entre as mesmas na cinética de absorção. Nas condições experimentais, obteve-se evidência de um padrão duplo de absorção do anion fosfato. A absorção radicular mostrou-se mais eficiente que a foliar em termos de quantidade absorvida e de transporte a longa distância
Excised roots obtained from 8 varieties of rice (IAC-164, 165 and 1246, Batatais, Caqui, Dourado Precoce, 90 Dias and Senbon) were used to study the kinetics of P uptake. Three cultivars (IAC-164, 90 Dias and Senbon) were employed in an experiment designed to compare root and leaf uptake and to evaluate the long distance transport. The main conclusions were as follows: a) after 180 minutes of contact with the external solution the uptake reached a maximum in the case of varieties IAC-164 and 165 , 90 Dias and Dourado Precoce; the same took place with the remaining cultivars after 240 minutes; b) the best fitting for individual varieties was obtained by using eiter potential or exponential models of adjustment wherein time was the independent variable and rate of uptake was the dependent one. c) IAC-164 and IAC-165 showed the highest efficiency of absorption while Dourado Precoce and 90 dias showed the lowest one. d) some evidence for the operation of a dual uptake mechanism was obtained when data from all varieties were put together; e) root absorption was usually higher than foliar uptake.
Estudos sobre a nutrição mineral do arroz. XVI, absorção radicular e foliar do rádio fósforo por diversas variedades* * Con ajuda da FAPESP, CNEN, CNPq e BNDE.
Studies on the mineral nutrition of the rice plant. XVI. root and foliar uptake of raiophosphate by several cultivars
E. MalavoltaI; A.F. VecchiatoII; H.W. TakahashiII; H.J. KliemannII; J.A. AzevedoII; M.D. ThomaziII; P.J. Carvalho GenoII; S.R.F. LeãoII
IDepartamento de Química, E.S.A. "Luiz de Queiroz" USP
IIEstudantes de Pós-Graduação, Disciplina LQI-860, Nutrição Mineral de Plantas
RESUMO
Estudando-se a absorção do rádio fósforo por raízes destacadas das variedades IAC-164, 165 e 1246, Batatais, Caqui, Dourado precoce, 90 dias e Senbon (as primeiras nacionais, a última japonesa) verificou-se diferença entre as mesmas na cinética de absorção. Nas condições experimentais, obteve-se evidência de um padrão duplo de absorção do anion fosfato.
A absorção radicular mostrou-se mais eficiente que a foliar em termos de quantidade absorvida e de transporte a longa distância
SUMMARY
Excised roots obtained from 8 varieties of rice (IAC-164, 165 and 1246, Batatais, Caqui, Dourado Precoce, 90 Dias and Senbon) were used to study the kinetics of P uptake. Three cultivars (IAC-164, 90 Dias and Senbon) were employed in an experiment designed to compare root and leaf uptake and to evaluate the long distance transport.
The main conclusions were as follows:
a) after 180 minutes of contact with the external solution the uptake reached a maximum in the case of varieties IAC-164 and 165 , 90 Dias and Dourado Precoce; the same took place with the remaining cultivars after 240 minutes;
b) the best fitting for individual varieties was obtained by using eiter potential or exponential models of adjustment wherein time was the independent variable and rate of uptake was the dependent one.
c) IAC-164 and IAC-165 showed the highest efficiency of absorption while Dourado Precoce and 90 dias showed the lowest one.
d) some evidence for the operation of a dual uptake mechanism was obtained when data from all varieties were put together;
e) root absorption was usually higher than foliar uptake.
Texto completo disponível apenas em PDF.
Full text available only in PDF format.
CO-AUTORES
Estudantes de pós-graduação: E.A. Pauletto, J.H;. Campeio Jr., J.R. de Freitas, L.F. Cavalcanti, M.L. Liva, M.F. Fiore, O. Primavesi, S.M. Fonseca, A. Parada, G. Martins, J.C. Gonçalves, J.F. Centurion, L.A.B.C. de Vasconcellos, M. de Almeida, M.E. Marchetti, O.A.P. Pereira, P.F.S. Martins, S. Buzetti, Técnica de laboratório: CP. Cabral.
LITERATURA CITADA
Entregue para publicação em 23/09/1982.
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- HOAGLAND, D.R.; ARNON, D.I., 1950. The water culture method for growing plants without soil. Calif. Agric. Expt. Sta. Circ, 347.
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- MALAVOLTA, E. et alii, 1977. Estudos sobre a nutrição mineral do sorgo granífero. VI. Absorção de fosfato por raízes destacadas de plantas de três variedades comerciais. An. Esc. Sup. Agric. "Luiz de Queiroz" 34: 383-406.
- MALAVOLTA, E. et alii, 1979. Estudos sobre a nutrição mineral do sorgo sacarino (Sorghum bicolor (L.) Moench. cv. Brands. II. absorção e redistribuição do radiofósforo. An. Esc. Sup. Agric. "Luiz de Queiroz" 36: 203-229.
- NOGGLE, J.C.; FRIED M., 1960. Akinetic analysis of phosphate absorption by excised roots of millet, barley and alfafa. Soil Sci. Amer. Proc 24(1): 33-35.
- OLIVER, W.G., 1952. Absorption and translocation of phosphorus of by foliage. Sci. Agri. 32: 427-432.
- RASTOGI, A.K.; MAHAJAN, J.P.; SINHA, S.B., 1981. Phosphorus utilization by three rice varieties at different stages of growth in a vertisol. J. Nuclear Agric. Biol. 10: 48-50.
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Datas de Publicação
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Publicação nesta coleção
05 Abr 2012 -
Data do Fascículo
1982
Histórico
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Recebido
23 Set 1982
