Osmotic stress is the most important of the abiotic stresses that lead to limitation of growth and yield in rapeseed. This study was conducted to examine the effect of cycocel seed priming on osmotic stress tolerance in germination and early growth stages of rapeseed, as a factorial experiment based on completely randomized design at Agriculture College of Shiraz University in 2012. The treatments included seed priming in three cycocel concentrations: 0 (without priming as control), 2.5 and 3.5 g L-1 and osmotic stress in five levels: 0 (as control), -0.3, -0.6, -0.9 and -1.2 MPa using polyethylene glycol. The results showed that osmotic stress was significantly reduced germination percentage (15.1%), germination rate (15.3%), radicle length (29.5%), plumule length (31.6%), radicle fresh weight (22.4%), plumule fresh weight (37.6%) and vigor index (39.9%). Furthermore, osmotic stress leads to increase radicle to plumule fresh weight and radicle to plumule length ratio as 6.8 and 24.3 percent, respectively. Seed priming with cycocel reduced the adverse effects of osmotic stress on measured parameters. Although, there was no positive effect on germination percentage and rate under osmotic and nonosmotic conditions for cycocel in both concentrations, but cycocel at 3.5 g L-1 appeared to have a greater positive effect than 2.5 g L-1. Considering positive impact of cycocel seed priming on the reduction adverse effects of osmotic stress further research on cycocel seed priming and osmotic stress tolerance is recommended under field conditions.
In order to study the responses of redstem filaree (Erodium cicutarium L.) seed germination to temperature levels, an experiment was carried out in a completely randomized design with four replications and twelve levels of temperature (0, 3, 5, 7, 10, 12, 15, 20, 25, 30, 35, 40 0C). Results showed that the effect of treatments on germination properties of redstem was significant, so the highest percentage of germination was achieved at 150C and reduced with increasing temperature and was totally inhibited at 40ºC. Based on a linear regression between germination rate and temperature, the cardinal temperatures: minimum (Tmin), optimum (To) and maximum (Tmax) were determined: 0, 15.20 and 37.18 ºC, respectively. A significant difference was not observed in plumule length at a range of 5-30°C that showed that it is less sensitive to temperature in comparison with root length. Highest wet-dry weight was achieved at 20 °C that was not different by 10, 12 and 20°C. Above results suggest that redstem failure could grow in a wide range of growing conditions, but prefers temperate zones. The results of this study are important to understanding thermal requirements and improvement of management strategies of redstem filaree.
Page 1 from 1 |
© 2024 CC BY-NC 4.0 | Iranian Journal of Seed Research
Designed & Developed by : Yektaweb