Effect of gibberellic acid on germination and seedling growth in different sorghum genotypes under salt stress condition

In order to study the effects of priming on germination of sorghum varieties under salt stress conditions, a factorial experiment was conducted in a randomized complete blocks design with four replications at Department of Agronomy and Plant Breeding, Faculty of Agriculture, University of Ilam in 2017. Treatments consisted of four levels of salinity (control, 70, 140 and 210 mM NaCl), four priming using Gibberellic acid hormone (no prime, 2.5, 5 and 7.5 mg/L) and four sorghum varieties (Superdan, Pegah, KFS2 and KFS1). The result showed that with increasing salinity levels, length and dry weight of root, coleoptile and shoot, germination rate, germination percentage and seed vigor decreased. The highest percentage and rate of germination was observed in KSF2 variety in 0 and 70 mM NaCl and in KFS1 variety in 140 and 210 mM. Priming showed significant effect on the studied traits except for fresh weight and germination percentage. The highest germination rate was observed in 0 and 2.5 mg/L gibberellic acid in KFS1 variety and in 5 and 7.5 mg/L in KFS2 variety. In general, priming improved germination indices under salinity stress.