The response of three tossa jute cultivars Ordinaire, 5-Doigts and Acc : Sud 2 to salt stress was evaluated at germination and young plant stages. Five NaCl concentrations: 0; 30; 60; 90 and 120 mM NaCl were used. Seeds were submitted to NaCl in petri dishes and germination was checked every day during thirty days in a completely randomized design with four replicates. Four-week old plants were submitted in pots to the same five NaCl concentrations by irrigation every two days for two weeks in screen house. NaCl reduced seed germination rate in all cultivars from day 2 to day 30 and the germination index. At the end of the 30 days, salt stress reduced the final germination percentages with a significant difference among cultivars: cultivar 5-doigts was the least affected than the two other cultivars. Salt effect caused a reduction of young plant growth whatever the growth parameter considered with a significant difference among cultivars. The growth of cultivar Acc:Sud 2 was more affected by salt stress with the lowest salt tolerance index whereas that of cultivar Ordinaire was the least affected with the highest salt tolerance index. Thus, cultivar 5-Doigts appeared as the most resistant to salt stress at germination stage among the three cultivars; whereas cultivar Ordinaire followed by 5-Doigts was the most salt resistant at young plant stage.

In this study, the response of seed germination of six African eggplant cultivars produced in Benin Republic (Dangbo, Kpinman, Adja-Ouèrè, Togan, Côte d’Ivoire and Kombara F1) to salt stress was investigated with the aim to determine their relative salt resistance level. The experiment was laid out in a completely randomized design with four replications. Seeds were subjected in Petri dishes to five NaCl concentrations (0; 30; 60; 90 and 120 mM). Seed germination was checked every day during twenty days incubation period. Germination index (GI), percentage of final germination (PFG) and salt tolerance index (STI) were calculated for each cultivar. Salt stress induced a significant reduction of GI(P < 0.001) and PFG (P <0.05) with a difference among cultivars. A significant difference (P <0.001) was observed among cultivars STI: cultivar Togan showed the highest STI (0.96) followed by Adja-Ouèrè (0.89) and Dangbo (0.76) whereas Côte d’Ivoire (0.38) and Kombara F1 (0.35) showed the weakest STI values. Thus cultivar Togan appeared as the most salt resistant whereas Côte d’Ivoire and Kombara F1were the most salt sensitive. For the first time, we demonstrated a variability of relative salinity resistance among local African eggplant cultivars at germination stage.

Salt stress is one of the abiotic factors that cause a depressive effect on plants. This work aims to evaluate the effect of salt stress on growth of young plants of 7 cultivars (Adja-ouere, Côte d'Ivoire, Dangbo, Kpinman, Kombara F1, Lanman and Togan) of African eggplant (Solanum macrocarpon) produced in Benin, locally called Gboma, in order to determine their relative salt-resistance levels. Five NaCl concentrations (0; 30; 60; 90 and 120 mM) were applied to 4-weeks old plants for 2 weeks in a completely randomized design with 3 replicates. Results revealed that the 3 root growth parameters evaluated were only significantly affected for one of the 7 cultivars while for the growth parameters of the aerial part, at least 4 cultivars were significantly affected except for leaf number. Thus, growth of aerial part was more sensitive to salt stress than that of root part. Cultivar Dangbo, which did not undergo significant reduction in growth for none of the 9 parameters evaluated, was the most salt resistant. It was followed by Togan which underwent significant growth reduction for only 3 growth parameters and only at the highest NaCl concentrations used. On the other hand, cultivar Kombara F1 which underwent a significant growth reduction from the lowest NaCl concentrations used for 4 of the nine parameters evaluated was the most salt sensitive. It was followed by Lanman, Kpinman and Adja-ouere with respectively 3, 2 and 2 growth parameters significantly reduced at the lowest NaCl concentrations used. Cultivar Côte d'Ivoire showed intermediate behavior.

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.