WATER-RETAINING POLYMER MITIGATES THE WATER DEFICIT IN Schinus terebinthifolia: PHOTOSYNTHETIC METABOLISM AND INITIAL GROWTH

Abstract

ABSTRACT The use of water-retaining polymer (hydrogel) can mitigate the damage to the photosynthetic apparatus and increase the robustness of young plants under water deficit conditions. Thus, the aim of this study was to evaluate the effect of water-retaining polymer on the morphophysiological aspects of Schinus terebinthifolia Raddi submitted to water deficit. The studied water regimes were characterized by three plant irrigation management: 1) control: irrigated daily, 2) stress: water deficit (irrigation suspension) and 3) stress + hydrogel: water deficit + water-retaining polymer. The plants were submitted to irrigation suspension until photosynthesis approached zero [1st P0], followed by resumption of irrigation (REI) for 15 days. After REI, until recovery of photosynthetic rate of plants, the maintenance of irrigation of all plants for 90 days, characterizing the final recovery (125th day of experiment). The photosynthetic rate reached values close to zero in plants under stress on the 20th day of water restriction, whereas the plants in conditions with hydrogel did not show a decrease in leaf metabolism. Excluding intercellular CO2 concentration, physiological parameters were lower on 1st P0 in plants under water deficit grown without hydrogel than those in plants grown with hydrogel, but all plants showed physiological plasticity. The use hydrogel contributed to the maintenance of the photosynthetic capacity of S. terebinthifolia under water deficit.

Keywords

• Brazilian pink pepper
• Cerrado biome
• hydrogel
• physiological plasticity