Evaluation of salt tolerance in maize (Zea mays L.) at seedling stage through morphological characters and salt tolerance index

Abiotic stressors such as salinity cause major yield losses in maize (Zea mays). To reduce the impact of salinity and breed for salt tolerance, precise phenotypic screening of maize genotypes at seedling stage is imperative. A laboratory experiment was conducted in the Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during rabi season (November-March) of 2017-18. Twenty maize inbred lines were assessed for salt tolerance at both germination and the seedling stage. The experiment was conducted using a completely randomized block design with three replications and four treatments viz. T-0 (0 dS m(-1)), T-1 (5 dS m(-1)), T-2 (10 dS m(-1)) and T-3 (15 dS m(-1)). The analysis of variance revealed highly significant (p < 0.001) differences in genotypes, treatments and interaction of genotype x treatment for most of the germination, shoot and root traits except root shoot ratio (fresh). Overall, the germination and shoot trait performances were more affected for most of the genotypes viz. ML13, ML25, ML03 with increasing the salinity level while less affected for root traits. The superior performances under control conditions (T-0) was revealed by ML05 and under salt stress conditions (T-1, T-2, T-3), the genotype ML28. Most of the shoot and root traits revealed stronger and significant correlations with each other except root shoot ratio for fresh and dry weights. The results of salt tolerance index (STI) indicated the superiority of genotype ML28 followed by the genotypes ML05, ML10, ML26, and ML19. These genotypes should be considered for further salt tolerance breeding in maize.