Effects of salinity, alkalinity and temperature on germination of Medicago ruthenica seeds.

The effects of salinity,alkalinity and temperature on germination of two accessions of Medicago ruthenica under different treatments of temperature(10/20℃,15/25℃,20/30℃),NaCl(0,50mmol/L,100mmol/L,150mmol/L,200mmol/L,250mmol/L) and Na2CO3(0,5mmol/L,10mmol/L,15mmol/L,20mmol/L,25mmol/L) were studied.The results showed that the germination percentage and the germination rate were not significantly affected by low salt concentrations and their interactions with temperature,but at higher level of salt concentrations,there were significant effects on germination percentage and the germination rate.The optimum temperature for seed germination was 15/25℃.Radicles of M.ruthenica were significantly affected by low salt concentrations,but not for hypocotyl.M.ruthenica germinated well in some Na2CO3 concentrations lower than 20mmol/L,germination percentage of two accessions of M.ruthenica were higher than 60% at 15mmol/L Na2CO3(pH=10.95).The tolerance of Linxia was higher than Caodian.