Under drought stress simulated by different concentrations of PEG 6000, the rate of germination and ernmergence were both reduced in each osmotic potential, but the final germination percentage was not affected. The germirnnation percentage was reduced by 3.9％ ～ 86.9％ compared to the control with the decrease of osmotic potential at rn-0.5 ～ - 1.0 MPa, and there was no emergence at -0.6～ - 1.0 MPa. On the 7th day, ungerminated seeds of each rntreament were transferred to the distilled water, the germination percentage reached 97.3％ ～ 98.3％, and the difference rnwas not significant compared to the control. Drought stress reduced seed vigor, mean germination time (MGT) increased rnby 0.1 ～ 1.5 d, germination index (GI) deceased by 2.9％ ～ 96.45％, and seedling vigor index(SVI) (during -0.1 rn～ -0.5 MPa) deceased by 5.0％ ～ 23.8％. Drought stress reduced shoot and root length, while the shoot length derncreased more than root length, root/shoot ratio was highly increased with osmotic decreasing.%采用不同渗透势聚乙二醇(PEG 6000)模拟干旱胁迫处理,观察油菜种子的萌发及生长状况.结果表明,干旱胁迫不同程度降低了油菜种子的萌发速率和出苗速率,-0.5～-1.0 MPa处理的最终发芽率随着渗透势的降低而显著降低,较对照降低了3.9%～86.9%,在-0.6～-1.0 MPa渗透势范围内不能成苗.试验7 d后将不同胁迫条件下未萌发的种子转入蒸馏水后均迅速萌发,第8天发芽率达到97.3%～98.3%,与对照差异不显著.干旱胁迫降低了种子活力,随着渗透势的降低,种子的平均发芽天数增长0.1～1.5 d,发芽指数降低了2.9%～96.45%,幼苗活力指数(-0.1～-0.5 MPa)降低了5.0%～23.8%.干旱胁迫同时降低茎长和根长,但茎长的降低幅度明显大干根长,根/茎比值表现较强的增加趋势.
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