Higher salt concentration severely affects seed germination of ten Indian genotypes of lucerne (Medicago sativa L.)

Lucerne (Medicago sativa L.) is the world's most important and ancient legume forage crop. It is moderately tolerant to salinity, but crop productivity is hampered. Salinity affects plant development, starting from seed germination to the reproductive stage. ISSR markers were employed to assess the genetic diversity among India's ten most common lucerne genotypes; the nine ISSR primers showed 83.50% polymorphism. The dendrogram revealed lower bootstrap support for group I; genotypes from group II were genetically distinct. Seed germination performance among the genotypes was studied at 0 (control), 85.55, 171, 256, and 342 mM NaCl concentrations. Higher germination was observed under control conditions. At a salt concentration of 85.55 mM NaCl, the genotypes under study showed less variation for germination and seedling characters. All germination indices and seedling parameters decrease with an increase in salt concentrations. Among the ten genotypes, Alamdar-51 showed high germination indices and seedling parameters under a high salinity level of 256 mM NaCl, indicating its ability for germination and initial growth under high saline conditions. At salinity concentrations of 342 mM NaCl, seed germination of all genotypes was severely affected. RL-88 and Kutchi selection showed the highest recovery of seed germination when seeds were transferred from a saline concentration to distilled water. These two genotypes demonstrated resistance to prolonged exposure to unfavorable salinized environments. This evaluation approach was found to be effective in identifying genotypes based on seed germination and early seedling growth stage under salinity stress.