Sodium nitroprusside effect on drought tolerance of perennial ryegrass in germination and early seedling growth stage

This experiment was conducted to determine morphological and physiological responses of perennial ryegrass (Lolium perenne L.) at the germination and early seedling growth stage to drought stress and sodium nitroprusside (nitric oxide donor) application in horticultural science department at the University of Zanjan in 2015. Turfgrass seeds were soaked for six hours in 0 (distilled water), 200, 400 and 600 micromolar of sodium nitroprusside solutions, and for drought stress treatments, germination and early seedling growth was done over the water potential range of 0 (distilled water), -1, -4 and -8 bar by polyethylene glycol. Generally, decline in water potential reduced seed germination percentage, root and shoot length, leaves chlorophyll and carotenoids content, whereas electrolyte leakage and proline content increased with decreasing of water potential. Sodium nitroprusside application at 400 and 600 µM ameliorate adverse effects of drought stress in all factors. However, in all water potentials, 600 µM treatment had no significant difference with control plants in electrolyte leakage, whereas 400 µM treatment reduced electrolyte leakage. Leaves proline content increased with decreasing water potential. Besides, treated plants with sodium nitroproside had more proline than untreated plants.
In conclusion, among different investigated sodium nitroprpside concentrations, treated plants with 400 µM sodium nitroproside showed the best results.