Screening for salt tolerance in maize and comparative evaluation on chemical composition and mineral nutrients

Abstract

Soil salinity is one of the significant environmental issues that have adverse effects on growth and productivity in Maize (Zea mays). Ultimately, the level of soil salinity hampers grain nutrition in maize. The availability of salt-tolerant maize genotypes, with an adequate grain nutritional quality, is a challenge in agriculture. Despite numerous nutritional studies in maize have been conducted, no report has been made on how nutrition is being affected under saline conditions. Therefore, the objective of this study was to screen the elite genotypes could sustain chemical composition and mineral nutrients under saline conditions. The hydroponic system was used to screen twenty genotypes of maize for salinity tolerance at the seedling stage. The study employed a completely randomized design (CRD) to test the genotypes under four different levels of salinity (control, 0, 4, 8 and 12dS/m). At the maturity stage, the genotypes were further screened in saline and normal field conditions. Randomized complete block design (RCBD) under split-plot arrangement with four different levels of salinity (control, 0, 4, 8 and 12dS/m) was used. Quantitative analysis of mineral contents was performed using inductively coupled plasma mass spectrometry (ICP-MS). Both maize under normal and saline field conditions were analyzed. Greenhouse hydroponic screening revealed that G-12, G-13 and G-15 performed best in morphological and physiological traits under saline condition. G-12, G-13 and G-15 performed best in field screening under normal and saline conditions based on yield and yield-related components (plant height, grain yield per plant, 100-grain weight and number of grains per cob). Grain chemical composition showed that G-12, G-13 and G-15 contained high protein (5.93-11.79%) and carbohydrate contents under saline conditions. G-15 was found to have the highest concentration of nutrients such as Ca, Fe and Zn under salinity. Further, the effect of ion antagonism was found to play a vital role in the decrease or increase of mineral nutrients in 20 genotypes under saline conditions. The study results concluded that G- 15 performed the best among the 20 genotypes of maize recommended for cultivation under saline condition.