关键词: 四翅滨藜, 萌发, 生长, 保护酶

Abstract:

The seed germination rate, germination index, germination value, vigor index, growth of radical and hypocotyls and activities of protective enzymes of Atriplex canescens were investigated under NaC1 and Na₂CO₃ stresses. The results showed that: 1) While low NaC1 concentration (0.05 mol ·L^-1) promoted the germination rate, germination index and germination value of Atriplex canescens seeds, high NaCl, as well as Na₂CO₃, inhibited these parameters, and the inhibition was aggravated with the increasing salinity. Under Na₂CO₃ stress, seeds were not able to germinate at 0.25 mol ·L^-1 Na+ concentration. The osmotic stresses were the dominant factor to inhibit those three parameters in seed germination period. 2) The length and growth rate of hypocotyls and radical, and vigor index under NaCl treatment were 1-5 times higher than Na₂CO₃ treatment, which suggested that high pH value was the main factor to affect the seedling growth. 3) At low concentrations of NaCl treatment (NaCl≤0.1 mol ·L^-1), SOD and POD in Atriplex canescens seeds played the principal role, while at high concentrations of NaCl treatment (NaCl＞0.1 mol ·L^-1), the POD and CAT were the principal factor. The changes of protective enzymes of the seeds in low concentration Na₂CO₃ stress were to the same as that under low concentration NaCl stress. POD maintained a high activity only in high concentration of Na₂CO₃ treatment, however, POD activity started to decline when the Na+ concentration was higher than 0.2 mol ·L^-1. For all above factors the injuries imposed by Na₂CO₃ stress were greater than by NaCl stress.

Key words: Atriplex canescens, germination, growth, protective enzymes