低温胁迫对玉米苗期叶片生理特性的影响

Effects of Physiological Characteristics under Low Temperature in Maize Leaves

为进一步筛选玉米耐低温种质资源,实验以前期萌芽期低温筛选获得的4份玉米自交系C71、京33、东46(低温敏感型)、东91为材料,三叶一心期分别在24℃、6℃条件下培养48 h,测定叶片丙二醛含量与电导率、保护酶活性及渗透调节物质含量。结果表明,在6℃条件下,较对照相比,东91鲜重下降但不显著,其余三个材料均显著下降;东46丙二醛含量下降但不显著,其余3个材料均显著上升;除京33外,其余3个自交系电导率显著增加。东91玉米自交系苯丙氨酸解氨酶活性显著上升,其余3个玉米自交系均显著下降;4个玉米自交系超氧化物歧化酶活性均显著上升;C71玉米自交系过氧化物酶活性显著下降,其余3个材料均呈显著上升。除东46外其余3个自交系脯氨酸含量均显著上升;C71与东46的可溶性糖含量显著下降;4种玉米自交系的可溶性蛋白含量均显著增加;基于以上结果得出各材料耐低温性由强到弱依次为东91、京33、C71、东46。实验结果可为培育玉米耐低温种质资源评价提供理论依据。

Four maize inbred lines C71,Jing 33,Dong 46(low temperature sensitive type)and Dong 91 obtained from low temperature screening at early germination stage were cultured at 24℃and 6℃for 48 h at three leaf and one heart stage,respectively.Malondialdehyde content,electrical conductivity,protective enzyme activity and osmoregulation substance content in leaves were measured.The results showed that at 6℃,the fresh weight of dong91 decreased,but not significantly,the other three materials decreased significantly;the malondialdehyde content of dong 46 decreased but not significantly,the other three materials increased significantly;except Jing 33,the conductivity of the other three inbred lines increased significantly.The phenylalanine ammonia lyase activity of dong 91 maize inbred line increased significantly,the other three maize inbred lines decreased significantly;the superoxide dismutase activity of four maize inbred lines increased significantly;the peroxidase activity of C71 maize inbred line decreased significantly,and the other three maize inbred lines increased significantly.Except for dong46,the proline content of the other three inbred lines increased significantly;the soluble sugar content of C71 and dong46 decreased significantly;compared with the control,the soluble protein content of four maize inbred lines increased significantly under low temperature stress;based on the above results,it was concluded that the low temperature tolerance of all materials was dong91>jing33>C71>dong46.The experimental results can provide theoretical basis for breeding maize germplasm resources with low temperature tolerance.