Evaluation of local finger millet (Eleusine coracana (L.) Gaertn.) landraces for salinity tolerance using growth and biochemical traits at the seedling stage

Abstract

Although finger millet is considered the future food, there are currently very few reports on how it reacts to salinity stress. This study aimed to compare the responses of twenty-seven native finger millet landraces under salt stress (0 mM to 250 mM NaCl in Hoagland solution). The degree of germination, seedling growth, biomass output, carotenoid content, membrane damage, and mineral accumulation were used to assess stress tolerance. With an increase in NaCl concentration, all landraces saw a drop in biomass production, shoot length, root length, and germination percentage. The decline was greater in ST-JA-SM and less in ST-JA-WA among landraces. All of the landraces showed a decrease in carotenoid content (108.76 ± 7.56 to 1.96 ± 0.83 µg mg⁻¹ FW) with increasing salt concentration, whereas malondialdehyde (MDA) content (0.17 ± 0.05 to 8.36 ± 0.53 µM g⁻¹ FW) was found to be increasing due to the stress imposed by salinity. The salt stress-sensitive landraces ST-JA-SM had greater MDA than the salt stress-tolerant ST-JA-WA. NaCl stress increased sodium and potassium levels in the seedlings of all the landraces. The magnitude of Na⁺ and K⁺ ions accumulation was higher in ST-JA-WA and less in ST-JA-SM. The salt tolerance indices for K⁺ ranged from 0.94 to 1.19, and that of Na⁺ ranged from 0.71 to 1.51. Combined these findings suggest that ST-JA-SM is stress-sensitive and ST-JA-WA is a stress-tolerant landrace that can be exploited in crop improvement programs. Additionally, it can be used as a participant in research on stress tolerance alleviation with noble elements like silicon or selenium.