Investigating the effect of pretreatment on germination and seedling growth of two rape cultivars (Brassica napus L.) under salt stress conditions

This experiment was conducted in order to evaluate the effects of osmo-priming on the characteristics of germination, seedling and some physiological characteristics of two cultivars of rapeseed (Brassica napus L.) under saline conditions. The seeds of two spring rape varieties were pretreated with 29.5 mM potassium nitrate (KNO3) for 12 hours at 30 degrees Celsius. In the first experiment after priming, 25 primed and unprimed seeds were placed in petri dishes with 4 levels of salinity (0, 50, 100 and 150 mM of NaCl) in a completely randomized design in four replications. The results showed that the germination percentage of primed seeds was higher than non-primed seeds.In the second experiment, 20 primed and unprimed seeds were planted in pots filled with perlite and peat at a ratio of 3:1. The pots were kept for three weeks in the greenhouse with a temperature of 26/16 degrees Celsius . The pots were watered every day with saline solutions (0, 50, 100 and 150 mM of NaCl). The results of multi-way interaction also showed that, primed seeds had higher antioxidant enzyme activity and higher content of soluble sugars and proline, at the same time, cell membrane damage in them was lower due to lower concentration of malondialdehyde compared to non-primed seeds. Under salinity conditions of 150 mM, the highest dry weight, antioxidant activity, and accumulation of soluble sugars and lower concentration of malondialdehyde were observed in Hyola 401 variety. This research showed that priming with KNO3 improves canola seed germination under stress conditions.