Abstract

Soil salinity constitutes a global threat to world food security given its deleterious effects on crop yield and the sustainability of arable lands. A comparative study was done on the changes induced by salinity on the growth, chlorophyll, metabolites, mineral distribution and productivity of three varieties of eggplant (Solanum melongena L). Research was effected in the green house (0, 50, 100, and 200 mM NaCl) and on the field (0 and 50 mM NaCl). The growth parameters (leaf area, number of leaves, stem height and noose diameter), dry biomass of roots, shoots and ratio, chlorophyll contents, and mineral distribution (K⁺, Ca²⁺, Mg²⁺, Zn²⁺, Fe³⁺, Mn²⁺, Cu²⁺, P, N and Na⁺/K⁺) decreased (p < 0.05) from 50 mM NaCl for all eggplant varieties studied, while Na⁺ increased. Some metabolites (Total free amino acids, soluble proteins, total soluble carbohydrates, proline, total phenol, glutathione, Superoxide dismutase, peroxidase, flavonoids and vitamin C) significantly increased (P < 0.01) with salinity from 50 mM NaCl for all varieties. Productivity (flowering and fruiting time, number of flowers and fruits and yields) was equally affected by salinity. The Djamba and Yalo varieties manifested better results for all parameters studied, compared to Kalenda. Their higher accumulation of metabolites suggested tolerance for moderate salinity stress.

Key words: Distribution, growth, metabolites, mineral distribution, productivity, salinity, Solanum melongena.