Effects of Calcium on Seed Germination of Fraxinus chinensisun under Salt Stress

[Objective] The aim was to increase the salt resistance of Fraxinus chinensisun in seed germination stage.[Method] With the seeds of F.chinensisun as the materials,after they were pretreated,the germination tests were done with different culture mediums.The effects of different treatments on the germination energy,germination rate and vigor index of F.chinensisun were studied.[Result] Under salt stress,the germination rate of F.chinensisun was decreased by 29% than that of CK.When 20 mmol/L Ca(NO3)2 was added,the germination rate was higher than that of the treatment under salt stress.The germination rates of treatments with other Calcium concn.were all decreased and were lower than that of treatment under salt stress.Under salt stress,the vigor index of seed was decreased by 52% than that of CK.The vigor index of the seed was the biggest when treated by 20 mmol/L Ca(NO3)2,being 61% higher than that of treatment under salt stress.Under salt stress,the fresh weight,shoot length and root length of F.chinensisun seedling were decreased by 38%,40%,46% than that of CK resp..When Calium was 40 mmol/L,the fresh weight,shoot length and root length were all higher than that of the treatment under salt stress,and the fresh weight and root length were 1.22 and 1.23 times of that of CK resp.[Conclusion] Calcium with 20 and 40 mmol/L had obviously mitigative effect on salt stress.