Effect of seed priming with various concentrations of KNO3 on sunflower seed germination parameters in in vitro drought conditions

Seed priming is technique for controlled seed hydratation which allows activation of pre-germinative metabolic processes. It has been successfully used for improving germination parameters in different crops. The study was conducted in 2012, at the Institute of Field and Vegetable Crops, Novi Sad, Serbia, in order to assess the effect of seed priming on four germination parameters (germination, germination index, mean germination time and time to 50% germination) of sunflower in in vitro drought conditions. Drought conditions (-0.8 MPa) were simulated using PEG 6000. Seed priming was conducted with soaking seed in water and different KNO3 solutions (0.1, 0.5 and 1%) for 12 h. Seed priming treatment with 0.1% KNO3 showed the best results and improved germination parameters : germination index, mean germination time and time to 50% germination of untreated seed (control). Seed priming showed no improvement in germination percentage in comparison to the control. Control had high germination (98%) and there was no possibility for its significant improvement with seed priming. This study showed that seed priming could improve some germination parameters of sunflower seed in in vitro drought conditions. Seed priming could be used as a simple method for overcoming problems related to a poor germination and seedling establishment in soil drought conditions. Main advantages of seed priming method are its simplicity and no requirements for expensive equipment and chemicals