Standardization of NaCl doses for saline stress induction in Jatropha curcas L.

Abstract

The present study proposes to define the doses considered severe and moderate NaCl used in experimental trials of Jatropha curcas up to eight days after sowing. The results presented in this study are based on phenological and physiological indicators to define the doses of NaCl from the concept of lethal dose. The experiment was carried out using a completely randomized design with a factorial consisting of two accessions of J. curcas (CNPAPM-X and CNPAPM-III) and five doses of NaCl (0, 50, 100, 150, 200 mM NaCl). The germination rate, seedling height, stem diameter, dry mass and Na⁺, K⁺ contents in addition to the K⁺/Na⁺ ratio of leaves, stems and roots were evaluated. It was evidenced in the experimental conditions imposed that the accesses presented different mechanisms of response to the saline stresses. Additionally, there was obtained, as a moderate and severe dose, standardized for salt stress tests in J. curcas with up to eight days after sowing, the doses of 100 and 50 mM, respectively.