Trocas gasosas e condutância estomática em três espécies de gramíneas

Gas exchanges and stomatal conductance on three gramineous species

I. BIOTECNOLOGIA, FISIOLOGIA DE PLANTAS E FITOQUÍMICA

Trocas gasosas e condutância estomática em três espécies de gramíneas¹

Gas exchanges and stomatal conductance on three gramineous species

Eduardo Caruso Machado^{I, II}; Ana Maria Magalhães Andrade Lagôa^{I, II}

^ISeção de Fisiologia, Instituto Agronômico, Caixa Postal 28, 13001-970 Campinas (SP)

^IICom bolsa do CNPq

RESUMO

Avaliou-se, sob condições naturais e sem deficiência hídrica, o comportamento diário das taxas de assimilação de CO₂ (A) e de transpiração (E), a condutância estomática (g) e a eficiência fotossintética do uso de água (E/A) em milho (C4), arroz (C3) e trigo (C3). Nas três espécies, a curva de resposta de A em função da irradiância (I), apresentou a forma de uma hipérbole retangular, porém em milho não houve saturação lumínica. A resposta de g em relação a I apresentou a mesma forma, respondendo E linearmente, nas três espécies. Em relação à variação de g, a curva de resposta de A também mostrou a forma de hipérbole retangular, enquanto E respondeu linearmente. Devido à resposta diferencial de A e de E, tanto em função de I como de g, a razão E/A aumentou com o aumento de I. As espécies C3 (arroz e trigo) revelaram valores maiores de E/A que a C4 (milho), em todos os níveis de I e valores de g, indicando melhor adaptabilidade da C4 na limitação de abertura estomática.

Termos de indexação: arroz, Oryza sativa L., milho, Zea mays L., trigo, Triticum aestivum L., fotossíntese, transpiração.

ABSTRACT

Under natural condition and without water deficit, assimilation of CO₂ (A) and transpiration (E) rates, stomatal conductance (g) and photosyntetic efficiency of water use (E/A), were monitored daily on maize (C4), rice (C3) and wheat (C3). In all species, the shape of response curves of A in function of irradiance (I), was a retangular hyperbole. However, luminic saturation was not observed in maize. Stomatal conductance response curve in function of I was also a retangular hyperbole, while E was linear in all species. Due to differential response of A and E, as a function of I as well as g, the ratio E/A was increased with the increase of I. The C3 species (rice and wheat) showed higher values of E/A than the C4 specie (maize), in all levels of I and g, showing the better C4 adaptation when stomatal limitation aperture occurs.

Index terms: rice, Oryza sativa L., maize, Zea mays L., wheat, Triticum aestivum L., photosynthesis, transpiration.

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Recebido para publicação em 23 de setembro e aceito em 30 de novembro de 1994.

• BEADLE, C.L.; LONG, S.P.; IMBAMBA, S.K.; HALL, D.O. & OLEMBO, R.J. Photosynthesis in relation to plant production in terrestrial environments. 1 .ed. Oxford, Tycooly Publishing, 1985. 156p.
• BLACK, C.C. Efficiency of carbon assimilation. In: NEYRA, C.A., ed. Biochemical basis of plant breeding: carbon metabolism. Boca Raton, C.R.C. Press, 1985. v.l, p.73-88.
• BURROWS, F.J. & MILTHORPE, F.L. Stomatal conductance in the control of gas exchange. In: KOZLOWSKI, T.T., ed. Water deficits and plant growth. New York, Academic Press, 1976. v. 4, p. 103-152.
• CEULEMANS, R.; HINCKLEY, T.M. & IMPENS, I. Stomatal response of hybrid poplar to incident light, sudden darkening and leaf excision. Physiologia Plantaram, Copenhagen, 75(2):174-182, 1989.
• CORNISH, K.; RADIN, J.W.; TURCOTTE, E.L.; LU, Z. & ZEIGER, E. Enhanced photosynthesis and stomatal condutance of pima cotton (Gossypium barbadense L.) bred for increased yield. Plant Physiology, Lancaster, 97(2):484-489, 1991.
• COWAN, I.R. Regulation of water use in relation to carbon gain in higher plants. In: LANGE, O.L.; NOBEL, P.S.; OSMOND, C.B. & ZIEGLER, H., eds. Physiological plant ecology. II. Water relations and carbon assimilation. Berlin, Springer-Verlag, 1982. v. 12B, p. 589-613. (Encyclopedia of plant physiology)
• COWAN, I.R. & TROUGHTON, J.H. The relative role of stomata in transpiration and assimilation. Planta, Berlin, 97(4):325-336, 1971.
• DAI, Z.; EDWARD, G.E. & KU, M.S.B. Control of photosynthesis and stomatal condutance in Ricinus communis L. (Castor bean) by leaf to air vapor pressure deficit. Plant Physiology, Lancaster, 99(4): 1426-1434, 1992.
• DOWNES, R.W. Relationship between evolutionary adaptation and gas exchange characteristics of diverse sorghum taxa. Australian Journal of Biological Science, Melbourne, 24(4):843-852, 1971a.
• DOWNES, R.W. Adaptation of sorghum plants to light intensity: its effect on gas exchange in response to changes in light, temperature, and CO₂ In: HATCH, M.D.; OSMOND, C.G. & SLATYER, R.O., eds. Photosynthesis and photorespiration. New York, Wiley - Interscience, 1971b. p. 57-62.
• DUBBE, D.R.; FARQUHAR, G.D. & RASCHKE, K. Effect of abscisic acid on the gain of the feedback loop involving carbon dioxide and stomata. Plant Physiology, Lancaster, 62(3):413-417, 1978.
• DWYER, M. & STEWART, D.W. Effect of leaf age and position on net photosynthetic rates in maize (Zea mays L.). Agricultural and Forest Meteorology, Amsterdam, 37(1):29-46, 1986.
• FARQUHAR, G.D. & RASCHKE,K. On the resistance to transpiration of the sites of evaporation within the leaf. Plant Physiology, Lancaster, 60(6): 1000-1005, 1978.
• FARQUHAR, G.D.; SCHULZE, E.D. & KÜPPERS, M. Responses to humidity by stomata of Nicotina glauca L. and Corylus avellana L. are consistent with the optimization of carbon dioxide uptake with respect to water loss. Australian Journal of Plant Physiology, Melbourne, 7(3):315-327, 1980.
• FARQUHAR, G.D. & SHARKEY, T.D. Stomatal condutance and photosynthesis. Annual Review of Plant Physiology, Boca Raton, 33:317-345, 1982.
• HUTMACHER, R.B & KRIEG, D.R. Photosynthetic rate control in cotton. Stomatal and nostomatal factors. Plant Physiology, Lancaster, 73(3):658-661, 1983.
• MACHADO, E.C.; LAGOA, A.M.M.A. & TICELLI, M. Relações fonte-dreno em trigo submetido à deficiência hídrica no estádio reprodutivo. Revista Brasileira de Fisiologia Vegetal, São Carlos, 5(2):145-150, 1993.
• MACHADO, E.C.; LAGOA, A.M.M.A.; TICELLI, M.; AZZINI, L.E. & TISSELLI F°., O. Fotossíntese e crescimento de panículas em arroz de sequeiro (Oryza sativa L. cv. IAC-165). Revista Brasileira de Botânica, São Paulo, 17(1):37-43, 1994a.
• MACHADO, E.C.; QUAGGIO, J.A.; LAGOA, A.M.M.A.; TICELLI, M. & FURLANI, RR. Trocas gasosas e relações hídricas em laranjeiras com clorose variegada dos citros. Revista Brasileira de Fisiologia Vegetal, São Carlos, 6(1):53-57, 1994b.
• MACHADO, E.C.; SILVEIRA, J.A.G. da; VITORELLO, V.A. & RODRIGUES, I.L.M. Fotossíntese, remobilização de reservas e crescimento de grãos em dois híbridos de milho sob deficiência hídrica na fase de enchimento dos grãos. Bragantia, Campinas, 51(2): 151-159, 1992.
• MARSHALL, B. & BISCOE, P.V. A model for C3 leaves descriting the dependence of net photosynthesis on irradiance: I. Derivation. Journal of Experimental Botany, Oxford, 31(120):29-39, 1980.
• PASSIOURA, J.B. Water in the soil-plant-atmosphere continuum. In: LANGE, O.L.; NOBEL, P.S.; OSMOND, C.B. & ZIEGLER,H., eds. Physiological plant ecology. II. Water relations and carbon assimilation. Berlin, Springer-Verlag, 1982. v. 12B, p. 5-33. (Encyclopedia of plant physiology)
• RASCHKE, K. Movements using turgor mechanisms. In: HAUPT, W. & FEINLEIB, M.E., eds. Physiology of movements. Berlin, Springer-Verlag, 1979. v. 7, p.383-441. (Encyclopedia of plant physiology)
• SCHULZE, E.D. & HALL, A.E. Stomatal responses, water loss and CO₂ assimilation rates of plants in contrasting environments. LANGE, O.L.; NOBEL, P.S.; OSMOND, C.B. & ZIEGLER, H., eds. Physiological plant ecology. II. Water relations and carbon assimilation. Berlin, Springer-Verlag, 1982. v. 12B, p. 181-230. (Encyclopedia of plant physiology)
• TANAKA, A.; KAWANO, K. & YAMAGUCHI, I. Photosynthesis, respiration, and plant type of the tropical rice plant. Los Baños, the International Rice Research Institute, 1966. 46p. Technical Bulletin, 7.
• TURNER, N.C. & BEGG, J.E. Stomatal behavior and water status of maize, sorghum, and tobacco under field conditions. I. At high soil water potential. Plant Physiology, Lancaster, 51(1):31-36, 1973.
• VU, J.C.V.; YELENOSKY, G. & BAUSHER, M.G. CO2 exchange rate, stomatal condutance, and transpiration in attached leaves of 'Valência' orange. HortScience, Alexandria, 21(1):143-144, 1986.

1

Trabalho parcialmente financiado pelo CNPq.

Datas de Publicação

• Publicação nesta coleção
  16 Out 2007
• Data do Fascículo
  1994

Histórico

• Recebido
  23 Set 1994
• Aceito
  30 Nov 1994