乙烯利浸种对聚乙二醇胁迫下玉米种子萌发的影响

为了优选出能使玉米种子在干旱胁迫下最佳萌发的乙烯利浸种浓度，用0、100、200、400、800 mg/L的乙烯利对玉米（‘三北2号’）种子浸种24 h，再分别用0%、5%、10%、15%的聚乙二醇(PEG6000)模拟干旱处理，测定20个双重胁迫处理组合下玉米种子发芽率、幼苗长度、MDA含量、CAT活性和POD活性，并运用方差分析和多重比较方法进行差异显著性检验。结果表明：（1）100~800 mg/L的乙烯利都能提高PEG6000胁迫下玉米种子的发芽率和幼苗长度，同时降低MDA含量，增强POD和CAT活性。（2）各指标在200 mg/L乙烯利浸种时与相同PEG水平下0 mg/L乙烯利处理有显著差异(P<0.05)。200 mg/L乙烯利浸种能显著缓解玉米幼苗在5%~15% PEG6000模拟下的干旱胁迫。

The Effects of Ethephon on the Germination of Corn Seeds Stressed by Polyethylene Glycol

To explore the optimization concentration of ethephon on the germination of corn seeds under drought stress, corn seeds were soaked by ethephon with the concentrations of 0 mg/L, 100 mg/L, 200 mg/L, 400 mg/L and 800 mg/L respectively for 24 hours. After that, the corn seeds were treated with PEG6000 for 7 days respectively for the simulation of different drought stress. The concentrations of PEG6000 were 0%, 5%, 10% and 15% respectively. And then, the germination rate, seedling length, MDA content, CAT activity and POD activity of the corn seedling under the double stress of every treatment were determined. And the variance analysis and multiple comparisons were used to study the relationship of different treatments. The results showed that (1) the germination rate, seedling length; CAT activity and POD activity of the corn were enhanced with the ethephon of 100-800 mg/L under the same PEG6000 drought stress, and the seedling MDA content were reduced with it. (2)There were significant differences (P<0.05) between 200 mg/L ethephon treatment and 0 mg/L ethephon treatment at the same PEG6000 concentration on each determined index. Therefore, 200 mg/L ethephon could alleviate the drought stress of the corn seedling simulated by PEG6000 with the concentrations of 5%-15%.