为探讨低温胁迫对玉米种子萌发及淀粉分解酶活性的影响,本试验采用玉米品种郑单958和先玉335作为供试材料,研究了适温(25℃)和低温(10℃、6℃)胁迫下玉米种子萌发特性及淀粉分解酶(α-淀粉酶、β-淀粉酶、总淀粉酶、淀粉磷酸化酶和淀粉去分支酶)活性的变化。结果表明,大多数淀粉分解酶的活性在适温下随萌发天数先上升后下降,而在低温胁迫下随萌发天数逐渐升高但都没有达到最适的酶活性。低温显著抑制了玉米种子的发芽率,降低了各淀粉分解酶的活性,其中6℃低温处理对两品种的淀粉分解酶活性的影响最为严重,尤其是对郑单958,而在各类淀粉分解酶中,淀粉去分支酶活性下降幅度最大(先玉335和郑单958下降幅度最高可达75.5%和83.0%)。从而表明低温胁迫对玉米种子萌发和淀粉分解酶活性均有重要的影响。
英文摘要:
To explore the effects of low temperature stress on the germination and starch decomposition enzymes activities of maize seeds, we adopted 25℃ as moderate temperature, ZD958 and XY335 as tested materials and studied changes of germination characteristics and starch decomposition enzymes (α-amylase, β-amylase, total amylase, starch phosphorylase and starch-debranching enzyme) activities of maize seeds in low temperature (10℃ and 6℃). The results showed that activities of each enzyme first increased and then decreased at moderate temperature, and gradually increased at low temperature along with germination days. Low temperature treatment significantly restrained germination and starch decomposition enzymes activities of maize seeds. Among them, inhibition of 6℃ treatment to decomposition enzymes activities of two cultivars was more severe compared to 10℃treatment, especially to those of ZD958. Among decomposition enzymes, starch-debranching enzyme activity had the biggest decline ranges (starch-debranching enzyme activity of XY335 and ZD958 decreased by 75.5% and 83.0%). The results above indicated that low temperature had significant effects on germination and decomposition enzymes activities of maize seeds.
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