Physiological responses of promising grasses for sideline revegetation of hydroelectrical reservoirs subjected to water deficit.
Hydroelectrical reservoirs sideline areas present peculiar characteristics, such as periods with water shortage and others with flooding. This could limit the vegetation development and sustainability. Aiming at obtaining information about physiological adaptations of species potentially promising for sideline revegetation of hydroelectrical reservoirs, our objective was to evaluate physiological characteristics of three grasses: Echinochloa pyramidalis, Setaria anceps and Paspalum paniculatum in response to water shortage. We evaluated: leaf water potential, photochemical efficiency of the photosystem II; levels of amino acids, starch, proteins, total soluble sugars, reducing sugars in leaves of plants cultivated in greenhouse with different water availability conditions (with and without watering). The leaf water potential was sensitive to water deficit, with values close of -3,0 MPa at the end of the experimental period. Regarding to this characteristic, significant differences were observed between treatments at the fifth day for E. pyramidalis and S. anceps and at the seventh day for P. paniculatum. The photochemical efficiency of photossystem II didn't show any significant difference, maintaining non-stressed plants values. In general, the species presented higher reducing sugar and total soluble sugar content when subjected to water shortage, indicating a larger capacity to support the damages caused by that deficit.