外源GA_3对NaCl胁迫下二月兰种子萌发的影响

Effects of exogenous GA_3 on germination of Orychophragmus violaceus seeds under NaCl stress

为研究外源GA3处理对NaCl胁迫下二月兰种子萌发的影响,设定了0、0.5%、1.0%和2.0%4个NaCl胁迫浓度,分别用0、50、100、200、300mg/L和500mg/L外源GA3溶液处理,测定二月兰种子的发芽势、发芽率、发芽指数、活力指数和α-淀粉酶活性。结果表明:在较低浓度NaCl胁迫下,GA3处理对二月兰种子萌发具有促进作用,其发芽势、发芽率、发芽指数、活力指数和α-淀粉酶活性均显著提高,且随着GA3浓度的增加,其促进作用增强,200 mg/L时达到最高。随着GA3浓度的继续增加,其促进作用逐渐下降,说明适宜浓度的GA3处理可以缓解NaCl胁迫对二月兰种子萌发的抑制作用;而在较高浓度NaCl胁迫下,GA3处理对二月兰种子的萌发的促进作用不明显。

O. violaceus seeds were treated respectively with 0,100,200,300 and 500 mg/L GA3 solutions, and then their germination vigor, germination rate, germination index, vitality index and α-amylase activity were determined respectively under various NaCI stresses（0,0.5%, 1.0% and 2.0% NaCl concentrations）. The results showed that under relatively low concentration NaCl stress, the GA3 treatments had an accelerating effect on the seed germination, making the seeds＇ germination vigor, germination rate, germination index, vitality index and α-amylase activity significantly improve, and the treatment with 200 mg/L GA3 had the best effect. But the GA3 treatments had not an obvious effect ＇on the seed germination under relatively high concentration NaCI stress.