Effects of NaCl stress on physiological characteristics and nuclear morphology in roots of Raphanus sativus L. seedlings

Using Raphanus sativus L.seedlings as material,root growth rate,root activity,POD activity and relative conductivity in roots were tested under 0.15 mol/L NaCl stress for different time,and nuclear morphological alteration of apical cells was also observed.The results showed that root growth rate and root activity of Raphanus sativus L.seedlings declined with the extension of NaCl stress,and they both declined rapidly when stress time was over 48 h.In contrast,POD activity and relative conductivity in roots increased constantly to the max during the NaCl stress by 12 h to 24 h,and then both declined when stress time was extended.Nuclear morphology in apical cells varied from circle to irregular shapes,and the characteristics of apoptosis appeared in different degrees.