The effects of some osmoprotectant compounds on growth parameters of pea plants (Pisum sativum) under saline conditions

Water solutions of several osmoregulatory/antioxidant compounds; CaCl₂, KNO₃, KH₂PO₄, thiamine and ascorbic acid were tested for their effects on salinity stress alleviation versus tap water as control. The compounds were applied either by seed priming or through rooting medium by irrigation water. Stem length, chlorophyll index and stomata conductance of developed leaves, as well as dry matter of roots and plants were periodically measured and the respective root relative growth rate and plant relative growth rate were computed. The salinity has significantly reduced the growth parameters of just emerged pea plants, as well as their physiological parameters. No significant salinity alleviation effect was achieved by seed priming, but the addition of the osmoregulatory compounds in the rooting medium through the irrigation water has significantly counteracted the salinity stress effects and has significantly improved growth parameters of pea plants. KH₂PO₄ and thiamine seems to be the most effective ones, by restoring the growth parameters of just emerged pea plants up to the level of non-saline conditions. As such, they could be highly effective to improve the stand establishment rate of young plants under adverse soil condition.