Effect of NaF on the Mitosis of Root tip of Onion

Different concentrations F were used separately to treat the root tip of onion,during the study on mitosis process of the root tip cells of onion,throuth normal squashed specimen.The author noticed lasted chromosome,chromosome bridge multiple polarization and other abnormal phenomena,for example,micronueleus.Meanwhile the result shows that,with a bigger concentration of F the growths of cells were inhibited more obviously,the mitosis co efficients were decreased.