In this study, we evaluated the salt resistance level of seven tomato cultivars Akikon, Tounvi, Thorgal, F1 Mongal, Padma, Petomech and TLCV15 at young plant stage. The experiment was laid out as a Randomized Complete Design (RCD) with four replications in a greenhouse. Three-week old plants from the seven cultivars were submitted in pots containing a mixture of potting soil and sand to five NaCl concentrations: 0; 30; 60; 90 and 120 mM NaCl corresponding respectively to an electric conductivity of 0.221; 3.827; 6.47; 10.56 and 14.02 dS.m-1 by irrigation every two days. Plant growth parameters were evaluated after two weeks. Salt effect caused a reduction of young plant growth whatever the growth parameter considered with a significant difference among cultivars. Growth of cultivars Padma, Akikon and Petomech was more affected by salt stress with two or three growth parameters significantly reduced at 30 mM NaCl whereas no growth parameter was significantly affected at less than 60 mM NaCl for cultivars Thorgal and Tounvi. Thus, cultivars Akikon, Petomech and Padma appeared as the most sensitive to salt stress. In contrast, cultivars Tounvi and Thorgal appeared as the most salt-resistant. Cultivars F1 Mongal and TLCV15 had intermediary behavior.

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Évaluation de la résistance à la salinité au stade jeune plant de quelques cultivars de piment (Capsicum spp.) du Benin

Aims: In this research study, salt resistance level of seven tomato cultivars grown in Benin, namely Akikon, Tounvi; F1 Mongal, Petomech, Padma, TLCV 15 and Thorgal was evaluated at the germination stage. Study Design: The experiment was laid out as a completely randomized design with four replications. Place and Duration of Study: The experiment was carried out in the Laboratory of Plant Physiology and Abiotic Stresses Study of University of Abomey-Calavi, Republic of Benin from May to June, 2017. Methodology: Seeds were submitted to treatment with four NaCl concentrations (0; 30; 60 and 90 mM NaCl) in Petri dishes. Seed germination was checked every day during ten days incubation period. Four replicates of 40 seeds each were used. Results: NaCl reduced seed germination rate in all cultivars from day 2 to day 10 and the germination index proportionately to NaCl concentration. At the end of the 10 days, salt stress reduced the final germination percentages with a significant difference among cultivars: cultivars F1 Mongal followed by Akikon, Thorgal, TLCV15 and Tounvi were less affected in comparison with the two other cultivars. Salt Tolerance Index was significantly variable according to the cultivar with the highest values for cultivars F1 Mongal (1.086), Akikon (1.028), TLCV15 (1.005) and Tounvi (0.989) and the weakest value for cultivar Petomech (0.436). Conclusion: NaCl stress delayed seed germination and reduced the rate of final germination. Salt Tolerance Index was variable among the seven cultivars. Based on this criterion, cultivars F1 Mongal, Akikon, TLCV15 and Tounvi were the most salt-resistant whereas Petomech was the most salt-sensitive at germination stage.

Salt stress is one of the major environmental constraints limiting agricultural productivity and influencing the concentration of bioactive compounds of vegetables. In this study, the effect of NaCl salt stress on nutrient contents of leaves in a cultivar of amaranth, an important leafy vegetable cultivated in some tropical regions worldwide, was evaluated. The experiment was carried out in a screen house at Center for Agricultural Research of Agonkanmey, Benin Republic as a randomized complete block design (RCBD) with three replications. Three weeks old plants were subjected in pots containing a mixture of potting soil and sand, to three concentrations (0, 30 and 90 mM) of NaCl by irrigation every two days. Nutrient contents in leaves were determined at maturity, after four weeks of stress, using standards methods. Proteins, total sugars, reducing sugars, lipids, potassium, calcium, vitamins C and B3 contents were not significantly affected by NaCl. Iron content increased significantly only at 30 mM NaCl but vitamins A, B1 and B2 contents increased significantly with increase in NaCl concentration. Thus, salt stress did not reduce nutritional values of this amaranth cultivar but improved its leaves nutritional quality by increasing vitamins A, B1 and B2 content.