Physiology and adaptation strategy of sesame (Sesamum indicum L.) to salinity

Abstract

Salinization is a global environmental problem. It is particularly prevalent in Africa in areas with a low rainfall trend such as the Senegalese groundnut basin where 20% of the land is affected. It reduces global food production by more than 10%. In Senegal, sesame (Sesamum indicum L.) moderately tolerant to drought and salinity is increasingly cultivated. It is an alternative to fight poverty in rural areas and allows the revaluation of salty land. The objective of this work is to evaluate at the early stage of reproduction the effect of salinity on the chlorophyll and ion (Na+ and Cl−) contents of four African varieties of sesame. The experimental device consists of randomized blocks with two factors and three repetitions. The sesame variety factor consists of four modalities (AS09, AS14, AS15 and AS25). The salinity factor or abiotic stress (NaCl) includes three modalities (0 mM, 17 mM and 34 mM). The parameters evaluated are the contents of Na+ and Cl− ions and of chlorophylls (Chl a, Chl b and total Chl). The results showed that the contents of chlorophylls (Chl a, Chl b and Chl) and Cl− and Na+ ions of sesame leaves increased with NaCl at 44 days after sowing. The Cl− contents of sesame leaves are higher than those of Na+ in all treatments. Chlorophyll increased with sesame varieties and salinity. Variety AS15 produced the greatest amounts of chlorophyll. Sesame, an inclusive-type plant, compartmentalizes Cl− and Na+ ions at the leaf level in vacuoles. He developed a tissue tolerance to salinity.