Impacts of Cold Stress on Activities of SOD and POD of Rice at Seedling Stage

The identified cold-resistance varieties Sujing No.2 and Lixinjing were used as experimental materials,and the cold-sensitive varieties Sanbaili,Yangkenuo,and Jiabala were used as control.The activity changes of SOD and POD in leaves of rice seedling at three different stages(before cold stress treatment,4 d after 6℃ treatment and resuming growth for 8 d) were studied.The results showed that after cold stress treatment,the activity of SOD in Sujing No.2 and Lixinjing increased by 110.7% and 87.4%,respectively;the activity of POD in Sujing No.2 and Lixinjing increased by 71.7% and 56.4%,respectively;the cold resistance of Sujing No.2 and Lixinjing was more stronger,the activities of SOD and POD in Sujing No.2 and Lixinjing increased more rapidly;the activities of SOD and POD in the cold-sensitive varieties and the control before and after cold stress treatment had not significant changes.