摘要:[目的]以聚乙二醇(PEG 6000)模拟干旱胁迫,探讨不同程度干旱胁迫对散叶生菜种子萌发的影响.[方法]以3种遗传背景不同的散叶生菜为材料,采用浓度分别为0 g/L、50 g/L、100 g/L、150 g/L、200 g/L、250 g/L、300 g/L的PEG 6000模拟干旱胁迫,分别测定其发芽率、发芽势、根长、芽长.[结果]生菜种子在不同浓度PEG 6000溶液的处理下,发芽率、发芽势、根长、芽长等各指标均受到了不同程度的抑制作用,且随PEG 6000的质量浓度不断增大,其各项指标均呈现下降趋势.在PEG 6000浓度为200 g/L时,各品种散叶生菜的发芽率均在85%以上,相对发芽率在90%以上,与对照组相比下降程度在10%以内;三个品种‘大速生’、‘辛普森’、‘玻璃脆’的发芽势较对照组分别降低了3%、3%、33%;平均根长分别下降0.3cm、1.12 cm、1.1cm;平均芽长与对照组相比分别下降了51%、58%、56%.[结论]PEG 6000的浓度为200 g/L时,对三种散叶生菜种子萌发的差异影响最大;3个品种中‘大速生,和‘辛普森’的耐旱性较好,‘玻璃脆’的耐旱性相对较弱.%[Objective]The effects of drought stress simulated by polyethylene glycol 6000 (PEG 6000) on effect of drought stress of different lettuce(Lactuca sativa L.) were studied during germination stage.[Methods]The drought tolerance among three kinds of lettuces with different genetic background were evaluated using seven treatment concentration of PEG 6000,ranging from 0 to 300 g/L during germination stage,and the germination rate,germination potential,root length,and bud length were analysed.[Results]The indexes of formation of the seeds with different concentrations of PEG 6000 appeared a decreasing trend.The germination rate,germination potential,root length,bud length,and other indexes were restrained on varying degrees.Moreover,the indexes of seeds were decreasesd with the increased concentration of PEG 6000.At the concentration of 200g/L,all of three species had more than 86 % germination rate,and more than 90 % relative germination rate.These two indexes decreased less than 10% compared with the control.Compared with the control,the germination potentials of ‘Dasusheng’,‘Xinpusen’,and ‘Bolicui’ decreased 3%,3%,and 33% respectively,the average root lengths decreased 0.3 cm,1.12 cm,and 1.1 cm respectively,the average bud lengths decreased 51%,58%,and 56 % respectively.[Conclusion]200 g/L PEG 6000 had the most impact on the seed germination of three species of lettuce.In these three species,‘Dasusheng’ and ‘Xinpusen’ were appeared the strong drought tolerance,while ‘Bolicui’ presented the weak drought tolerance.