Echophysiological aspects of Ocimum basilicum under saline stress and salicylic acid

Abstract

Basil (Ocimum basilicum L.) is one of the world’s most widely cultivated medicinal herbs, but its physiological processes are affected by salinity. Therefore, mitigation strategies against the harmful effects of salt on plants have been increasingly on demand, including the use of salicylic acid. Thus, the effect of salicylic acid on the ecophysiology of basil plants grown under saline stress was evaluated in two different periods. The experimental design was the randomized complete block design using the Box Central Composite matrix with five irrigation water electrical conductivities (0.5, 1.3, 3.25, 5.2, 6.0 and dS m-1) and five doses of salicylic acid (0.0, 0.29, 1.0, 1.71 and 2.0 mM), with five replicates. Gaseous exchanges, fluorescence and chlorophyll content were evaluated at 30 and 60 days after irrigation with saline water started. Data were evaluated by analysis of variance and regression and by correlation analysis. The water electrical conductivity negatively affected the analyzed variables, while the salicylic acid had a positive effect. The highest correlation between the variables was obtained at 30 days after the irrigation with saline water started. Salicylic acid treatment up to the dose of 1.0 mM has a beneficial effect on basil plants.