Effect of NaCl Salt Stress on Growth, Ions and Organic Solutes Contents in a Local Cultivar Kpinman of African Eggplant (Solanum macrocarpon L) in the Republic of Benin

Aims: This research has as objective to evaluate the effect of NaCl salt stress on African eggplant plant growth and to determine the implication of the accumulation of Na+, proline and soluble sugars and the reduction of K+ in the detrimental effect of NaCl in the growth of this plant species.

Study Design: The experiment was laid out in a Completely Randomized Design (CRD) having five treatments and three replications.

Place and Duration of Study: The experiment was carried out in screening house under natural conditions at the International Institute of Tropical Agriculture, Commune of Abomey-Calavi. Republic of Benin from June to august 2022.

Methodology: Five NaCI concentrations (0, 30, 60, 90 and 120 mM) were used to irrigate four weeks old plants for two weeks. Plant growth, sodium (Na), potassium (K), proline, and soluble sugars contents of leaves and roots were determined at the end of the experiment.

Results: Salt stress induced a significant reduction (P = .001) in shoot and root growth from 30 : 60 or 90 mM NaCI according to the growth parameter but had no impact on shoot water content. Leaf and roots Na+ contents significantly increased (P = .001) under salt stress whereas K+ content deoreased significantly (P = .05) only in root. Na change was observed for proline and soluble sugars contents in both leaf and root.

Conclusion: Salt stress reduces the growth of plants of African eggplant due mainly to Na+ ion toxicity. The ionic selectivity ratio (K+/ Na+) rather than the K+ ion content plays an important role in the response of plants of African eggplant to salt stress. Proline and soluble sugars accumulation appeared not to intervene.