The effect of melatonin and hydropriming on some physiological characteristics of Chickpea (Cicer arietinum L.) seed and seedling under salinity stress

Melatonin (N-acetyl-5- methoxytryptamine) as a plant growth regulator, natural compound that is in a large variety of plant species in roots, leaves, fruits and seeds have been identified. In order to investigate the effect of melatonin on some physiological characteristics of chickpea seed and seedling (Arman cultivar) under salinity stress, a factorial experiment was conducted based on a completely randomized design with four replications in 2017 at the Yasouj University. The factors included melatonin at concentrations of without-prim, 0, 25, 50, 75, 100 and 125 μM as the first factor, and different levels of salinity include 0, 25, 50, 75 and 100 mM sodium chloride, as the second factor. The results showed that in salinity levels of 100 and 50 mM, melatonin with concentration of 100 μM increased the seedling proline. In non stress conditions, priming with 25, 75 and 100 μM melatonin increased seedling potassium content. Also, in 100 mM salinity stress, priming with 50 and 75 μM melatonin increased potassium content in the seedling. Priming reduced the sodium content of seedling at salinity levels of 100 and 75 mM by 25 and 75 μM melatonin concentrations respectively. Overall, the results of this study showed that chickpea tolerate salinity stress at germination stage up to 100 mM, and the use of melatonin at these stage due to salinity tolerance has not a significant effect on the physiological indices of the seeds, and only hydropriming in this condition compared to non-primed by helping to absorb water by the plant has had a positive effect on the physiological process during germination.