论文部分内容阅读
利用大型活动遮雨棚池栽对夏玉米进行了出苗后的全程水分控制试验研究,探讨了不同生育期夏玉米叶面积、根系活力、叶片膜脂过氧化以及保护酶超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性对不同水分胁迫的生理反应与适应。结果表明:轻度受旱在大喇叭口至抽雄初期对植株叶面积影响不大,但抽雄后直至灌浆中期,轻度受旱持续时间长了也会对叶面积造成较大的不良影响。而重旱胁迫在各生育时期对叶面积的影响更为不利。干旱胁迫下,夏玉米生育进程中保护酶SOD、POD和CAT活性基本呈现一致下降的态势,膜脂过氧化作用增强,从而引发细胞内膜系统直接受损,可能是干旱逆境下作物主要的生理反应。各生育阶段因受旱时间和强度的不同,三个保护酶活性下降及膜脂过氧化产物丙二醛(MDA)积累均表现不同,随干旱胁迫的推进,短时期内对某些保护酶有一定的激发效应,即在大喇叭口期SOD和POD的活性有所增加,但此效应维持不长,其后骤降。受旱时间越长,受旱程度越重,则保护酶活性越低,MDA积累越多。根系对土壤干旱胁迫甚为敏感,玉米拔节期根系活力下降就见端倪,随受旱的延长及加剧将更加促使根系老化,根系活力快速衰减。
The large-scale activities shelter pond planted summer maize after the emergence of full moisture control experiments to explore the different growth stages of summer maize leaf area, root activity, leaf lipid peroxidation and protective enzymes superoxide dismutase (SOD ), Peroxidase (POD) and catalase (CAT) activities under different water stress. The results showed that mild drought had little effect on the plant leaf area in the early stage of poplar and tasseling, but the prolonged mild drought did not affect the leaf area significantly until the mid filling stage after tasseling. However, the effect of heavy drought stress on leaf area in each growth period is more unfavorable. Under drought stress, the activity of protective enzymes SOD, POD and CAT in summer maize growth process basically showed a consistent decline, membrane lipid peroxidation increased, leading to direct damage to the cell endometrial system may be the main physiological physiological response of crops under drought stress reaction. Due to the difference of drought time and intensity, the activities of three protective enzymes and the accumulation of malondialdehyde (MDA), a membrane lipid peroxidation product, differed at different growth stages. With the advance of drought stress, some protective enzymes A certain excitation effect, that is, the activity of SOD and POD in the big bell mouth increased, but the effect remained short, then plummeted. The longer the drought period, the heavier the degree of drought, the lower the protective enzyme activity, the more MDA accumulation. The root system is very sensitive to soil drought stress. The decline of root activity at jointing stage of corn will be seen. With the prolongation and aggravation of drought, root system aging and root vigor will decay rapidly.