O ácido salicílico alivia o estresse hídrico no aparato fotoquímico e qualidade das mudas de Schinus terebinthifolia

Abstract

ABSTRACT Water deficit adversely affects photosynthetic pigment synthesis, photochemical processes, and seedling quality. Exogenous foliar application of salicylic acid (SA) is hypothesized to contribute to photochemical regulation and increase stress tolerance. This study aimed to evaluate the effect of SA in alleviating the effects of water deficit stress on the photosynthetic photochemical activities and quality of Schinus terebinthifolia Raddi. seedlings. The seedlings were subjected to four regimes of water deficit: 0, 4, 8, and 12 days of water restriction (DWR), associated with the application of four concentrations of SA: 0, 50, 100, and 200 mg L-1 (via foliar spray; 10 mL per plant) during 48 days. Growth of S. terebinthifolia seedlings was adversely affected by longer duration of water restriction in absence of SA treatment. However, application of 200 mg L-1 of SA increased photosynthetic pigment levels, photochemical quantum efficiency in photosystem II, and absorbed energy conversion efficiency in seedlings under 12 DWR. The seedling quality was better at 7 and 12 DWR when associated with application of 100 and 200 mg L-1 SA, respectively. The exogenous application of SA contributed positively to pigment concentration and photochemical stability of photosynthesis, and it improved the quality of S. terebinthifolia seedlings subjected to long water restriction periods.