圆叶决明对低温胁迫的生理响应及施Ca^(2+)预防效果的研究

Physiology Respond of Chilling Stress and Effect of Spray Ca^(2+) on Chamaecrista rotundifolia

对圆叶决明(Chamaecristarotundifolia)牧草CPI86134品系苗期进行15、10、5、0℃的低温胁迫,以25℃胁迫为对照.结果表明:随低温胁迫强度的提高和胁迫时间的延长,植株体内O-·2净产生速率增加;同时植株体内活性氧清除酶SOD、POD、AsAPOD的活性在0～48h胁迫时间之内以较快的速率提高,48h之后提高速率趋缓.其中冷害温度0℃分别胁迫6、12、18、24h后,叶片光合色素含量较对照(25℃)下降21.89%、26.04%、28.16%、29.31%,可溶性蛋白质含量和O-·2净产生速率随胁迫时间延长而提高,活性氧清除酶SOD的活性随胁迫时间延长先上升而后下降.在胁迫前施Ca2+处理可明显降低叶片O-·2净产生速率和电解质渗透率,同时提高了光合色素含量和活性氧清除酶SOD活性,其中以0.5mmol/L浓度的CaCl2处理效果为最佳,说明Ca2+对低温胁迫下圆叶决明的膜结构起有效的保护作用.

The different chilling stress grads as 15,10,5℃ and 0℃ in comparison with 25℃ were treated on the variety CPI86134 of Chamaecrista rotundifolia.The results showed that net rate of O^-· _2 generation increased as chilling stress enhanced and longer;the contents of scavenging enzymes (SOD、POD、AsA-POD) also increased quickly in 48 hours under chilling stress,then slowly dropped.And after 6,12,18 and 24 hours treatment with 0℃ chilling stress on Chamaecrista rotundifolia,the content of chlorophyll (chl) increased 21.89%,26.04%,28.16% and 29.31% respectively than CK(25℃),dissolubility protein content and O^-· _2 net generation rate increased as well,the scavenging enzymes(SOD) activity increased at first,then dropped.The treatment of using Ca^2+ under chilling stress could significantly decreased the net rate of O^-· _2 generation and the leakage rate of electrolyte,the contents of scavenging enzymes SOD and the chlorophyll (chl) content increased as well.The effect of 0.5mmol/L CaCl_2 was the best,which indicated that Ca^2+ could protect the membrane structure of Chamaecrista rotundifolia under chilling stress.