Production of essential oil and the accumulation of solutes of the hydroponic basil under saline stress

Abstract

The objective of this work was to evaluate the effects of salinity on the content and yield of essential oil and on the accumulation of inorganic and organic solutes of basil cv. Toscano Folha de Alface, at different recirculation frequencies of nutrient solution and hydroponic systems. The experimental design was completely randomized, in a factorial scheme 3 x 2 + 1, where the first factor represents NaCl levels (0, 40 and 80 mM) and the second factor the recirculation frequencies of the nutrient solution (4 or 6 h) in hydroponic DFT system, and an additional treatment with nutrient solution without NaCl in NFT system. The variables analyzed were essential oil content, Na⁺, Cl^-, K⁺, K⁺ / Na⁺ ratio, soluble carbohydrate concentration, free amino acids, soluble proteins and free proline content. In general, reducing the recirculation frequency of the nutrient solution to six hours does not cause significant effects on the variables analyzed; The content and yield of the essential oil gradually reduces with increasing NaCl concentration; The salinity increases Na⁺, Cl^- contents and reduces K⁺ and K⁺ / Na⁺, in the organs of the evaluated plants; The accumulation of organic solutes in the leaves and roots of basil is a strategy of plants to reduce the deleterious effects of NaCl; The choice of the DFT or NFT hydroponic system does not cause significant changes in the analyzed variables.