伊犁地区5个引种白蜡对干旱胁迫的响应

Response of five introduced Fraxinus chinensis species to drought stress in Yili area

为探讨伊犁地区5个引种白蜡的抗旱性差异,为区域化推广栽培提供理论依据,以5个3 a生引种白蜡苗木为材料,采用盆栽控水试验方法,设置4个水分梯度(CK、T1、T2、T3,田间持水量分别为80%~85%、55%~60%、40%~45%、30%~35%),测定其SOD活性、POD活性、MDA含量、脯氨酸含量、可溶性蛋白含量、叶绿素含量和净光合速率(Pn)等指标,利用主成分分析、隶属度函数法与多元逐步回归法综合评价5个引种白蜡的抗旱性。结果表明:(1)干旱胁迫下脯氨酸含量、可溶性蛋白含量与对照相比显著增加,其中园蜡1号脯氨酸含量在T2处理下增加幅度最大,增加了361.85%,鲁蜡5号可溶性蛋白含量的T3处理较对照增加了284.87%。(2)随着干旱胁迫的增加,5种白蜡POD活性不断上升,1275在T3处理下较对照增加了373.88%。5个白蜡品种各处理组SOD活性相较于对照有所增加,其中金叶白蜡在T3处理下增加了118.70%。金叶白蜡MDA含量较低且变化不显著,其余4个品种MDA含量均表现为处理组显著高于对照组。(3)5种白蜡随干旱胁迫的增加,叶绿素含量不断降低,Pn显著降低,且叶绿素与Pn极显著相关,金叶白蜡叶绿素含量在T3处理下降低了55.51%,鲁蜡5号在T3处理下Pn降低了81.08%。(4)通过主成分分析结合隶属度函数法准确评价出5种白蜡抗旱性强弱顺序为鲁蜡5号>1275>鲁蜡6号>园蜡1号>金叶白蜡。

To provide a theoretical basis for future regional promotion and cultivation of Fraxinus chinensis,the difference of drought resistance of five introduced Fraxinus species in Yili was analyzed.The study used five three-year-old Fraxinus chinensis seedlings with four potted water control treatments of 80%~85%,55%~60%,40%~45%,and 30%~35%field moisture capacity as CK,T1,T2,T3.The SOD activity,POD activity,MDA content,proline content,soluble protein content,chlorophyll content,and net photosynthetic rate(Pn)were tested.The principal component analysis,membership function and multiple stepwise regression were used to evaluate the drought resistance of five introduced Fraxinus chinensis species.The results were as followes:(1)Under drought stress,proline content and soluble protein content increased significantly compared with the control.The proline content of Fraxinus velutina‘Yuanla-1’increased by 361.85%under T2 treatment,and the soluble protein content of F.chinensis‘Lula-5’increased by 284.87%under T3 treatment.(2)With the increase of drought stress,the POD activity of five species of Fraxinus chinensis increased continuously,and the POD activity of‘1275’in T3 treatment increased by 373.88%compared with the control.Compared with the control,the activity of SOD in each treatment group of five species of Fraxinus chinensis increased,and that of F.chinensis‘Jinye’increased by 118.70%under T3 treatment.The MDA content of F.chinensis‘Jinye’was lower,but the change of MDA was not significant.The MDA content of four species in the treatment groups was significantly higher than that in the control group.(3)With the increase of drought stress,the chlorophyll content of five species of Fraxinus chinensis decreased continuously.The Pn decreased significantly,and the chlorophyll content was highly significantly correlated with Pn.The chlorophyll content of F.chinensis‘Jinye’decreased by 55.51%in T3 treatment,and the Pn decreased by 81.08%in F.chinensis‘Lula-5’T3 treatment.The order of drought resistance of chosen five Fraxinus chinensis was F.chinensis‘Lula-5’>1275>F.chinensis‘Lula-6’>F.velutina‘Yuanla-1’>F.chinensis‘Jinye’.