Germination response of chemo-primed sorghum seeds to salinity

Abstract

Salinity is one of the most important environmental elements affecting plant growth and development. The study hypothesised that priming sorghum seed with growth stimulators alleviates salinity stress. The seeds were chemically primed for 3 hours with 50, 150, and 250 ppm of Indole acetic acid (IAA) and Gibberellic acid (GA3), at the 3 concentrations each. After that, the seeds were subjected to sodium chloride (NaCl) stress at concentrations of 50, 150, and 250 mM NaCl. The time it took for seedlings exposed to 50 mM NaCl to germinate after priming with GA3 was shorter than the time it took for seeds in the control of distilled water (22.2 hours).Despite the use of primers, the results demonstrated that increased salinity concentrations were deleterious to seedling vigour, shoot and root growth e.g., root length decreased from 6.3 cm in the control to 0.90 cm when 150 ppm GA3seeds were subjected to 250 mM NaCl. The findings imply that chemical priming with IAA and GA3 at concentrations of up to150ppm can hasten germination but other measures need to be employed to reduce deleterious effects of NaCl salinity >150 mM on plant growth and vigour.