ALVES, F. J. B.; http://lattes.cnpq.br/1230980029659365; ALVES, Francisco José Basílio.
Résumé:
When subjected to water stress conditions, depending on their intensity and duration, the
plants may suffer a negative effect on their water status, promoting stomata closure and,
consequently, a reduction in photosynthesis, limiting growth, which may lead to the death of
plants. The objective of this work was to evaluate the physiological and biochemical
responses of juremapreta
plants submitted to variable water availability conditions during
the nursery stage. Twelvemonthold
plants kept in plastic pots containing 5 kg of the
substrate composed of the subsoil soil mixture and bovine manure (2:1) were submitted to
two treatments: irrigated (control) and water deficit, which was imposed through the
suspension of irrigation. After 7 days of stress, the plants were rehydrated. The relative water
content (RWC), stomatal parameters and organic solutes contents were evaluated. The plants
responded quickly to the irrigation suspension, promoting stomata closure, reducing stomatal
conductance, transpiration and photosynthesis. The instantaneous efficiency in water use of
plants under water deficit remained high only until the middle of the period when irrigation
was suspended, and then declined until the last day of the water deficit. The water deficit
promoted soluble sugars and total amino acids accumulations, providing osmotic adjustment
and maintenance of RWC at acceptable levels. After rewatering, the plants showed recovery in
all evaluated parameters, demonstrating that the level of stress imposed did not cause
irreversible damages in the cells and tissues.
