NaCl胁迫对簕仔树种子发芽及幼苗生长的影响

Effects of NaCl Stress on Seed Germination and Seedlings Growth of Mimosa sepiaria Benth

[目的]研究NaCl胁迫对簕仔树种子发芽及幼苗生长的影响。[方法]采用不同NaCl浓度(0、50、100、150、200、250 mmol/L)处理簕仔树种子,测定种子萌发和幼苗生长有关指标。[结果]种子萌发试验表明,簕仔树种子的发芽率、发芽势、发芽指数和活力指数在浓度≤50 mmol/L的NaCl溶液处理下与对照无差异;但当NaCl浓度>50 mmol/L时,处理组与对照组间表现出显著或极显著差异;当NaCl浓度达到250 mmol/L时,处理组种子萌发的各项指标降到最低。幼苗生长试验表明,NaCl浓度≤50 mmol/L时,对幼苗的生长未表现出不利影响,而当盐胁迫浓度>50 mmol/L时,根长、根茎比、鲜重及干重等指标值急剧降低,幼苗生长被抑制。簕仔树种子萌发时盐胁迫的适宜值、临界值和极限值分别为50、150、250 mmol/L。[结论]簕仔树具有一定的耐盐性。

[Objective]The aim was to study the effects of NaCl stress on seed germination and seedling grouity of Mimosa sepiaria Benth.[Method]Mimosa sepiaria Benth seeds were treated with different concentrations of NaCl（0,50,100,150,200,250 mmol/L）,and related indicators of seed germination and seedling growth of Mimosa sepiaria Benth were determined.[Result]The seed germination results showed that germination percentage,germination energ,gemination index and vigor inde of the seeds had no notable differences with CK when seeds were treated with NaCl solutions less than 50 mmol/L,while there were significant or extreamly significant difference betwen treatment group and CK group,when seeds were treated with more than 50 mmol/L NaCl solution.All the indicators reduced to the lowest with the treatment of 250 mmol/L NaCl soltion. The seedling growth results showed that there were no adverse effects on the growth of the seedlings when the concentration of NaCl was less than 50 mmol/L.While when the concentration of salt stress was more than 50 mmol/L,length of the root and germ,freshweight,dryweight declined after germination,the growth of seedlings were inhibited.The appropriate parameters,limit value and critical concentration of salt stress were 50,150,250 mmol/L respectively during the seed germination.[Conclusion] Mimosa sepiaria Benth could bear salt stress at some degree.