Comportamento fisio-ecologico de plantas de kudzu (Pueraria spp.) : efeito da temperatura e da deficiencia hidrica sobre a assimilação do nitrato e balanço hidrico na planta

AUTOR(ES)
DATA DE PUBLICAÇÃO

1988

RESUMO

The effects of air temperature and water déficit on nitrate reductase activity (E.C.1.6.6.1),leaf diffusion resistance, leaf temperature and leaf relative water content were evaluated in two different environmental conditions. In the greenhouse, using Pueraria phaseoloides, the water deficit was induced by suspending the irrigation and in the field, Pueraria lobata plants were naturally submitted to both fluctuating air temperature and soil water availability. Measurements of the instantaneous radiant flux density, air temperature, relative humidity and soil water content were taken.Daily radiant flux density and the leaf-air vapor pressure deficit were calculated for the characterization of the microclimate conditions of the plant surroundings. Furthermore, more appropriated conditions were standarized for nitrate reductase assay in vivo in foliar tissue. In the field experiments, a considerable influence of air temperature on nitrate assimilation was found/ the greatest nitrate reductase acativity was observed between 28 and 29oC and a considerable decrease in temperatures above 33 and below 23oC.The increase in leaf diffusion resistance from 1,0 to 1,8 sec.cm-1 was associated to the increase in air temperature from 21 to 36oC. The increase in leaf diffusion resistance from 0,9 to 1,8 sec.cm ?1 was related to water depletion of field capacity from 71 to 50%. ...Note: The complete abstract is available with the full electronic digital thesis or dissertations

ASSUNTO(S)

fisiologia vegetal botanica ecologia vegetal kudzu

ACESSO AO ARTIGO

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