Breaking seed dormancy in Hippophae salicifolia, a high value medicinal plant

Seed dormancy is an important limiting factor in exploitation of an economically important species to its fullest. Hippophae salicifolia D. Don (seabuckthorn), a rich source of medicinal metabolites shows both exogenous and endogenous dormancy. Evidently, we recorded a high seed viability (94 %) but poor germination (22 %) of untreated seeds. We applied different pre-sowing seed priming treatments including NaCl (50, 100, 200, 500 mM), KNO3 (0.1, 0.2, 0.3 %), Thiourea (1, 2, 3 %), GA3 (100, 250, 500 mg/L), Sulphuric acid (98 %) and cold (4 °C) and warm water (65 °C) stratifications to explore improvements in its germination percentage, if any. We found KNO3 (0.1 %) and Thiourea (1 %) treatments to be superior to other methods for enhancement of mean seed germination percentage of H. salicifolia. Considering the practical applicability and cost effectiveness, these treatments can be applied to overcome seed dormancy and recommended for mass multiplication through seeds of H. salicifolia.