NaCl对玉米萌芽期生长及生理胁迫的效应

用不同浓度的NaCl溶液处理玉米自交系无名-5及杂交种垦玉7进行发芽试验,研究了它们在盐胁迫条件下,发芽势、芽长、根长、脯氨酸(Pro)含量、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的变化。结果表明,随NaCl溶液浓度的增加:(1)两品种玉米生长均受到严重抑制,发芽势降低,芽和根的长度均呈减小的趋势,总体来看,杂交种垦玉7的发芽势、芽和根的长势均好于自交系无名-5;(2)两品种玉米体内Pro含量均增加,且在NaCl浓度超过150mmol/L时,杂交种垦玉7体内Pro含量增加的幅度明显大于自交系无名-5,而使垦玉7对盐的适应能力强于无名-5;(3)两品种的CAT活性变化幅度均不大,但无名-5的CAT活性在各NaCl浓度条件下均高于垦玉7,这可能是由品种间本身差异造成的,而与品种的耐盐性无直接关系。而杂交种垦玉7的SOD活性增加幅度却明显大于无名-5,说明垦玉7在盐胁迫下可能主要通过体内的SOD来清除活性氧自由基从而缓解盐害,使其耐盐性优于无名-5。

Studies on Growth and Physiological Reaction of Zea mays in Embryoism under NaCl Stress

Zea mays seedlings of inbred line(Wuming-5) and hybrid(Kenyu7) were treated with different concentrations of NaCl solution.The effects of vigor of germination,the length of buds and roots,the contents of proline,and the activities of superoxide dismutase(SOD) and hydrogen peroxidase(CAT) were investigated.With the increasing of NaCl stress:(1)the growth of the two Zea mays varieties was inhibited ,the vigor of germination and the length of buds and roots were both reduced. While there are significant differences in morphology between the two different Zea mays varieties under NaCl stress,the morphological indicators of kenyu7 were superior to wuming-5.It showed that the halophile of Kenyu7 were better than Wuming-5;(2)the contents of proline of the two Zea mays varieties increased significantly,and under high NaCl stress(150mmol/L NaCl or above) the increasing amount of the contents of proline of Kenyu7 was higher than Wuming-5 ,so it showed that the injuries of Wuming-5 imposed by NaCl stress was greater than Kenyu7;(3)the activities of CAT of the two varieties were no obviously changed,while the activities of CAT of Wuming-5 were all higher than Kenyu7 under all concentrations of NaCl solution,which hadn''t showed the correlation between the activity of CAT and salinity tolerance.While the activities of SOD of Kenyu7 were changed more significantly than Wuming-5,which suggested that the salt tolerance of Kenyu7 was better than Wuming-5.