The effects of different concentrations of Zn￣(2+)ion on root growth,cell division,and nucleoli of Allium cepa were studied. The test Zn￣(2+) ion concentration was made up from zinc sulphate (ZnSO4. 7H2O) ranging fr...The effects of different concentrations of Zn￣(2+)ion on root growth,cell division,and nucleoli of Allium cepa were studied. The test Zn￣(2+) ion concentration was made up from zinc sulphate (ZnSO4. 7H2O) ranging from 10￣(-7) to 10￣(-2) mol/L. The solutions were prepared in tap water (pH =6. 5).The results indicated that Zn￣(2+) could obviously inhibit root growth at concentrations from 10￣(-4)to 10￣(-2) mol/L.Roots treated with zinc sulphate showed the presence of c-mitosis, anaphase bridges,including sticky and fluidized bridges (at 10￣(-3) to 10￣(-2) mol/L) , chromosome stickiness, irregularly shaped nuclei, broken nuclei and micronuclei. A toxicity effect was also observed on the nucleoli using silver staining technique after 48h of treatment with 10￣(-4)to 10￣(-2) mol/L Zn￣(2+), e. g,the nucleolar particulate material scattered around the nucleoli in the nucleus of root tip cells.展开更多
文摘The effects of different concentrations of Zn￣(2+)ion on root growth,cell division,and nucleoli of Allium cepa were studied. The test Zn￣(2+) ion concentration was made up from zinc sulphate (ZnSO4. 7H2O) ranging from 10￣(-7) to 10￣(-2) mol/L. The solutions were prepared in tap water (pH =6. 5).The results indicated that Zn￣(2+) could obviously inhibit root growth at concentrations from 10￣(-4)to 10￣(-2) mol/L.Roots treated with zinc sulphate showed the presence of c-mitosis, anaphase bridges,including sticky and fluidized bridges (at 10￣(-3) to 10￣(-2) mol/L) , chromosome stickiness, irregularly shaped nuclei, broken nuclei and micronuclei. A toxicity effect was also observed on the nucleoli using silver staining technique after 48h of treatment with 10￣(-4)to 10￣(-2) mol/L Zn￣(2+), e. g,the nucleolar particulate material scattered around the nucleoli in the nucleus of root tip cells.
