Effects of Cd~(2+) and NaCl Stress on Seed Germination of Alfalfa

Seeds of Medicago sativa L.cv.were used as test material to study the effects of different Cd2+and Salt contents on seed germination.The results showed that under the single stress of NaCl,with the increasing of the concentration,seed germination had been inhibitied obviously,seed germination force and germination percentage had been strongly inhibited,germination indexes and vigour indexes decreased.But MDA gradually increased then decreased;Under Cd2+stress,lower concentration of Cd2+promoted seeds germination,but the higher concentration of Cd2+inhibited seed germination,and with the concentration of Cd2+increasing,the MDA decreased and cell membrane of seeds had been affected strongly by Cd2+.Under the stress of the combination of NaCl and Cd2+,the stress effects such as seeds germinate percentage,germination vigour,bud length and root length were between two chemicals conducts stress separatly.