Effect of simulated drought stress and salt stress on seed germination of Scutellaria barbata

Scutellaria barbata seeds were used as an experimental model to study the effects of drought and salt stress on seed germination and seedling growth. Polyethylene glycol (PEG) was used to simulate drought stress, and mixed solutions of NaCl, Na2SO4, MgCl2, and (2 NaCl+Na2SO4) was used to simulate salt stress. The results show that: 1) Draught stress induced by 5% and 10% PEG solutions did not cause an effect on seed germination and seedling growth, but the 15% and 20% PEG solutions had significant inhibitory effects on seed germination and seedling growth (P<0.05), and the seeds did not germinate under stress induced by 25% PEG treatment. 2) Under salt stress, with increasing concentrations of Na2SO4 the germination rate and germination index showed a “fall-rise-fall” trend. With NaCl+MgCl2 salt stress, germination rate and germination index were negatively correlated with salt concentration. With NaCl salt stress, seedings did not grow. The seedling leaf area showed a negative correlation with the concentration of a Na2SO4+MgCl2 composite salt solution. A 0.3% concentration of Na2SO4, MgCl2, and compound salt showed a germination promoting effect, while concentrations higher than 0.6% had an inhibitory effect. Radicle length under the Na2SO4, MgCl2 salt stress, reduced with the increase of concentration; with the increase of composite salt concentration radicle length presented a “rise-fall” trend. These indicators of S. barbata seed germination and seedling growth showed different effects of drought and salt stress on seed germination and seedling growth.