NaCl和Na2CO3胁迫对黑麦草种子萌发及幼苗生理特性的影响

摘要

以黑麦草(Lolium perenne)为试验材料,分别进行NaCl(50、100、150、200 mmol/L)和Na2CO3(25、50、75、100 mmol/L)不同浓度胁迫处理,以加蒸馏水处理作对照,处理后研究NaC1和Na2CO3胁迫下对黑麦草种子萌发、叶片相对电导率和丙二醛(MDA)含量的影响.结果表明:①在NaCl和Na2CO3处理下,当Na+浓度≤50 mmol/L时,对发芽率和MDA含量没有显著影响,随着浓度的增加,特别是Na+≥150 mmol/L时,黑麦草种子各项萌发生理指标和MDA含量与对照相比均表现显著变化.②就NaCl和Na2CO3胁迫相比较,在相同Na+浓度下,处于Na2CO3胁迫下的黑麦草种子幼苗叶片相对电导率及MDA含量均明显高于NaC1胁迫.这说明NaCl和Na2CO3胁迫均对黑麦草种子和幼苗造成了不同程度的伤害,但在相同Na+浓度下,Na2CO3胁迫伤害程度大于NaC1胁迫,因此说明黑麦草种子和幼苗对NaCl的忍耐程度高于Na2CO3.%To study the effects of NaCl and Na2CO3 stress on the germination of Lolium perenne seeds,relative electrical conductivity and the content of MDA in leaves of L.perenne seedlings,the L.perenne seeds were treated with NaCl and Na2CO3 at different level,such as NaCl 50,100,150,200 mmol/L and Na2CO3 25,50,75,100 mmol/L,respectively.And the control group were treated with distilled water.The results showed that there were no significant effects on germination rate and the content of MDA when the concentration of Na+ less than 50 mmol/L.But with the increase of concentration,the germinated physioloical indexes and the content of MDA in leaves were obviously different from the control group.At the same concentration of Na+ germinated physioloical indexes,relative electrical conductivity and the content of MDA in leaves under Na2CO3 stress were significantly higher than those under NaCl stress.It showed that the seeds and seedlings were injured in varying degrees under NaCl and Na2CO3 stress,and the injury under NaCl stress were more than under Na2CO3 stress.It indicated that the tolerance of L.perenne seeds and seedlings to saline stress was higher than to alkaline stress.