Screening of finger millet genotypes for sodicity tolerance using the Na+/K+ ratio as a major physiological trait

Abstract

Sodicity affects a larger area than salinity, but research on the sodicity tolerance mechanism is limited. The study was carried out to screen 120 finger millet genotypes under sodic soil conditions and identify sodicity-tolerant genotypes. The experimental field soil conditions were sandy clay loam with pH 8.9, electrical conductivity (EC) 0.94 dSm^-1 and exchangeable sodium percentage (ESP) 21.5, which was naturally sodic. Grain yield per plant and Na⁺/K⁺ ratio were recorded for each genotype to screen sodicity tolerance among the genotypes. A significantly higher grain yield per plant than that of the sodicity-tolerant check variety TRY 1 (23.10 g) was observed in 30 finger millet genotypes. The analysis of sodium and potassium revealed that these 30 finger millet genotypes also recorded a significantly lower Na⁺/K⁺ ratio, which is comparatively lower than that of the sodicity-tolerant check variety TRY 1 (0.23 Na⁺/K⁺ ratio). The genotypes (FIN 3045, FIN 2875, FIN 3077, FIN 3015, FIN 3063, FIN 2861, FIN 3028, FIN 2867, FIN 2854, FIN 2860, FIN 2872, FIN 2896, FIN 4268, FIN 3034, FIN 3928, FIN 3104, FIN 3965, FIN 3091, FIN 2960, FIN 3994, FIN 4198, FIN 3174, FIN 3078, FIN 4288, FIN 4202, FIN 4238, FIN 3089, FIN 4205, FIN 3966 and FIN 3182) that recorded higher grain yield per plant and lower Na⁺/K⁺ ratio can be considered sodicity tolerant. These genotypes with a high grain yield per plant and a low Na+/K+ ratio could be utilized in stress breeding programs to develop sodicity-tolerant finger millet varieties.