Effect of NaCl and CaCl2 stress on germination indicators and seedling growth of canola

Canola (Brassica napus L.) is one of the most important oil seed crops in the world and Iran. Seed germination is the initial and most crucial stage in the life cycle of plants. Several environmental factors simultaneously influence germination. Salinity is a serious problem in many regions of the world including Iran. In order to investigation of NaCl and CaCl2 stress effect on germination indicators and seedling growth of canola, an experiment was conducted with four levels of salinity included (0, 50, 100 and 150 mmole) as a completely randomized design with four replication. Results showed that the effect of salinity on root length (RL), stem length (SL) and vigor index 1 (VI1) was significant. Control has the maximum stem length. Regression equations of germination rate (R50), SL, seedling dry weight (SDW) and maximum germination (Gmax) with salinity levels showed that all of these traits have negative strong relation with salinity levels. Control has the highest value of these traits and as with increase of salinity levels these traits were declined. The most strong relation was observed between SL with NaCl levels (y = -0.0178x + 8.418; R² = 0.9393). Results showed that with increase of mean germination time (MGT), R50 was declined as a linear model that this relationship in Nacl levels was stronger than CaCl2 levels. In conclusion the results of this study demonstrate that the shortened duration up to maximum percent of germination exists within canola seeds that exposed to lower salinity levels.