Effect of salinity stress on germination and seedling growth characteristics of blue panic grass (Panicum antidotale L.)

Salinity caused by sodium chlorides alters the ion balance and nutrient status of a plant. Therefore in order to investigate the effect of different levels of salinity on germination and seedling growth traits of blue panic grass (Panicum antidotal L.) an experiment was conducted in completely randomized design with four replications during 2011 growing season under green house conditions. Salinity applied at germination stage using five levels of 0, 2.5, 5, 7.5 and 10 dS m-1 with four replications. Germination indices were reduced by increasing salinity, so that a severe reduction happened at 2.5 dS m-1 (47% reduction in germination percentage compared to the control) and it was reached its lowest value at 10 dS m-1 (89% reduction in germination percentage compared to the control). The experiment at seedling stage included five salinity levels (0, 2.5, 5, 7.5 and 10 dS m-1) with three replications. This stage included three parts: 1- salinity application before emergence, 2- salinity application before emergence and 3- salinity application from planting until four leaf stage. At this stage, plant leaf area, root and stem dry weight and root to shoot ratio were significantly affected by salinity levels. At the second part of second experiment, root to shoot ratio increased at the salinity of 5 dS m-1 (i.e. 0.62 but for the control was 0.44). Overall results showed that blue panic grass was more sensitive to salinity at germination stage compared with seedling stage.