低温胁迫对不同基因型玉米种子萌发特性的影响

Effects of Low Temperature Stress on Seed Germination of Different Maize

以不同基因型玉米生产品种郑单958、先玉335、京科968和京农科728为试验材料,研究适温和低温胁迫下玉米种子萌发过程中发芽势、发芽率、芽长、根长、种子a-淀粉酶及保护酶活性等的变化,探讨低温胁迫对不同基因型玉米品种种子萌发特性的影响。结果表明,在25℃适温和10℃低温胁迫条件下,京科968和京农科728的发芽势和发芽率均高于郑单958和先玉335;在10℃低温胁迫下,京科968、京农科728的发芽势、发芽率显著高于郑单958和先玉335。10℃低温胁迫条件下,京科968和京农科728的芽长和根长显著高于郑单958和先玉335;在25℃适温条件下4个参试玉米品种的芽长和根长差异不显著。2个温度处理条件下,京科968和京农科728种子的α-淀粉酶、过氧化物酶(POD)和过氧化氢酶(CAT)活性均高于郑单958和先玉335,在10℃低温胁迫条件下优势更明显;丙二醛(MDA)含量在品种间呈相反趋势。在低温胁迫下,京科968和京农科728表现出较强的耐低温萌发能力。

An experiment was conducted to study the effects of low temperature stress on the germination potential, germination rate, bud length, root length, and α-amylase and protective enzyme activities of maize seeds. Fourwidely planted maize varieties in China, Zhengdan958(ZD958), Xianyu335(XY335), Jingke968(JK968), and Jingnongke728(JNK728) were used as materials, and a suitable temperature(25℃) for seed germination and a low temperature(10℃) were tested. Under both temperature conditions, the germination potentials and germination rates ofJK968 and JNK728 were higher than those of ZD958 and XY335. And JK968 had 11.25 and 10.41% higher germination potential and 9.95 and 4.56% higher germination rate than ZD958 and XY335. JNK728 had 10.12 and9.29% higher germination potential and 9.20 and 3.84% higher germination rate than Zhengdan958 and Xianyu335.The bud lengths and root lengths of JK 968 and JNK728 were significantly higher than those of ZD 958 and XY 335 at 10℃, however, no significant differences were found among the four maize varieties at 25℃. In addition, underboth temperature conditions, especially under 10℃, the activities of α-amylase, POD and CAT enzymes in JK968 and JNK728 were all higher than those in ZD958 and XY335, while the MDA content in JK968 and JNK728 waslower than those in ZD958 and XY335. Therefore JK968 and JNK728 showed stronger resistance to low temperature than ZD958 and XY335 during seed germination.