Comparison of Stress Effects of NaCl and Na_2CO_3 on Seed Germination and Seedling Growth of Festuca arundinacea Schreb

The seeds and seedlings of Festuca arundinacea Schreb were treated with NaCl(50,100,200,300 mmol/L)and Na2CO3(5,10,15,25 mmol/L)respectively,and the gernmination potential,gernmination rate,root length,seedling height,fresh weight,chlorophyll content,root activity,membrane permeability and MDA content were determined.The results showed:compared with the control,with the NaCl concentration increased,the germination potential,germination rate,root length of F.arundinacea decreased,leaf membrane permeability and root MDA contents increased,seedling height,fresh weight,chlorophyll content,root activity initially increased and then decreased;and root membrane permeability and leaf MDA content was initially slightly decreased and then increased.With Na2CO3 concentration increased,the seed germination potential,germination rate,root length,seedling height,fresh weight,chlorophyll content decreased,while membrane permeability and MDA content of root and leaf showed an upward trend,and root activity was initially increased and then decreased.Comprehensive analysis indicated that the threshold concentration of F.arundinacea tolerance to NaCl and Na2CO3 were 246.9,20.4 mmol/L respectively,therefore,the salt tolerance of F.arundinacea was stronger than that alkaline.