稀土对NaCl胁迫下矮牵牛幼苗生长抑制的缓解效应

Mitigation Effect of Rare-Earth on Seedling Growth and Rooting of Petunia under NaCl Stress

以矮牵牛为材料,采用组织培养的方法,探讨硝酸稀土对NaCl胁迫下矮牵牛幼苗生长抑制的缓解效应。结果表明,在试验区间范围内,采用90 mg.L-1硝酸稀土对0.4%的NaCl胁迫下矮牵牛的株高、单株鲜重和根长有明显的缓解效应,分别为:14.5%,19.9%和53.2%,对生根率缓解效应不明显;当NaCl浓度为0.8%,硝酸稀土对株高和单株鲜重缓解效应不明显,对根长和生根率反而有抑制作用,抑制效应分别达到34.6%和48.4%。在一定范围内硝酸稀土对NaCl胁迫矮牵牛根系的POD,SOD和CAT同工酶的活性均有促进作用,表达种类无明显变化。随着硝酸稀土处理浓度的提高,叶片POD同工酶活性呈现低-高-低变化,表达种类无明显变化;SOD同工酶活性增强,表达种类增多;CAT同工酶活性下降,表达种类减少。

By using tissue culture method,the mitigative effect of rare earth nitrate on the seedling growth and rooting of Petunia under NaCl stress was studied.The results showed that under NaCl concentration of 0.4%,the mitigative effects on plant height,fresh weight and root length were obvious,and when rare earth nitrate concentration reached 90 mg·L-1.Its values were 14.5%,19.9% and 53.2% respectively,but no visible effect appeared on the rooting rate.When NaCl concentration rose to 0.8%,no distinct effect appeared on plant height and fresh weight,but restraining effect showed in root length and rate,its values were 34.6% and 48.4%.In the certain range,the isozymes activity of POD,SOD and CAT promoted by rare earth nitrate on Petunia root under NaCl stress,and no expression type changed.With the increasing of concentration of rare-earth nitrate,the POD activity of leaf presented a current of low-high-low,and the SOD isozymes activity increased and expression types enhanced,while CAT isozymes activity and expression types decreased.