Screening of selected accessions of Ethiopian sesame (Sesame indicum L.) for salt tolerance

Salinity is one of the most severe abiotic stress that limits crop production and productivity especially in arid and semiarid areas of the world. It causes morphological, physiological, biochemical, and molecular changes and adversely affects plant growth and metabolism. However, crops respond and perform differently when exposed to salinity and some can be tolerant. Therefore, selection and characterization of germplasm is needed to obtain salt tolerant crops. In this study, the response of fifteen accessions of Ethiopian sesame were evaluated at two stage growth using different concentration of NaCl (0, 50, 100, 150 mM). Qualitative and quantitative parameters like plant height, shoot length, root length, leaf number, leaf area, fresh weight, dry weight, Na+ and K+ content were used to characterize and rank the accessions using salt tolerance index value. Though, the performance of all accession was different, significant reduction was found in plant height, shoot length, leaf area, leaf number, fresh weight, dry weight, and K+ content, whilst Na+ ion increased as salinity level increases. Based on overall performance, accessions were grouped as tolerant, moderately tolerant and sensitive. Among the studied accessions, 203104, 211921, 241332, 17712, 207955, and 202290 showed better performance with increasing salinity and classified as salt tolerant. Accessions 208671, 235404, 202355, and 228816 were moderately tolerant. The remaining accessions were ranked as salt sensitive. This study indicated the existence of substantial variability in terms of salt tolerance within all studied accessions of sesame. Therefore, the tolerant accessions can be utilized for diversification to salinity exposed environment and employed for stress related breeding.