普通小麦-欧山羊草异附加系对干旱胁迫的生理生化响应

Physiological and Biochemical Responses of Triticum aestivum-Aegilops biuncialis Addition Lines to Drought Stress

为探究异源染色体对小麦抗旱能力的影响,选取3个普通小麦-欧山羊草异附加系和3个普通小麦为试验材料,以聚乙二醇(PEG6000)模拟干旱胁迫,在苗期测定干旱胁迫下叶片丙二醛(MDA)积累量、可溶性蛋白含量和酶促防御系统(SOD、POD和CAT)活性变化。结果表明,随着干旱胁迫程度的加重和时间的延长,供试基因型所测定的五个生理指标的变化趋势较为一致。MDA含量都不断升高,三个普通小麦-欧山羊草异附加系(Ae9013、Ae9041和Ae9061)的MDA积累幅度较抗旱性最好的小麦对照晋麦47小,积累量也较少。三个异附加系的可溶性蛋白含量受干旱胁迫影响较小,虽有小幅度的下降,但保持着较高的含量。干旱胁迫下,各基因型的SOD、POD和CAT活力增加,在一定时间内,随着干旱胁迫的持续,晋麦47表现出先上升后下降的趋势,而Ae9013、Ae9041和Ae9061的SOD和POD活力随着胁迫程度的加重和时间的延长呈现不断上升趋势;Ae9013、Ae9041的CAT活力在15%PEG6000胁迫下不断增加,在25%PEG6000胁迫下先增加后下降,而Ae9061的CAT活力在高浓度PEG6000胁迫下仍持续增加。由此可见,普通小麦-欧山羊草异附加系具备更有效的酶促防御系统和渗透调节能力,说明U组染色体附加提高了小麦的抗旱能力。

Three Triticum aestivum-Aegilops.biuncialis Ub addition lines and three common wheat genotypes（controls）were tested in polyethylene glycol-simulated drought stress to investigate the effect of alien chromosome on drought resistance of wheat at seedling stage.Similar trends in the changes of molondialdehyde content（MDA）,soluble protein content,and the activity of enzymatic defensive system were observed in the six tested genotypes with the ever increasing of drought stress intensity and duration.The MDA accumulated continuously in all tested genotypes under drought stress,yet the MDA accumulation in the alien addition lines Ae9013,Ae9041 and Ae9061 were much lower than that in wheat controls.The soluble protein content of alien addition lines was less affected by drought stress,which was higher than that of the wheat controls.The activities of SOD,POD and CAT were increased in all tested genotypes under drought stress.The activities of the enzymatic de-fense system in the most drought resistant wheat control Jinmai 47,however,were increased firstly and declined slightly along with the lasting of drought stress process.The CAT activities in Ae9013 and Ae9041 were increased continuously under 15% PEG6000 stress,and increased and then decreased under 25% PEG6000 stress.In contrast,the CAT activity of Ae9061 was increased continuously under severe stress gradients.In summary,the three alien addition lines had stronger enzymatic defense system and higher osmotic adjustment potential,which means that U chromosome addition enhanced the drought resistance of common wheat.