Primary studies and identification of polyploid induction in Portulaca grandiflora Hook

Mutation treatment was performed on different parts of organizations of Portulaca grandiflora plant using different concentrations of colchicine solution and then ploidy identification was carried on variant plant with different methods in this experiment.The results showed that for the germinating seeds of Portulaca grandiflora,the highest variation rate was 11% treated by 0.05% colchicine for 12 h.As the apical portion,the highest variation rate was 75% treated by 0.10% colchicine for 48 h.For the root tip,4% DMSO and 0.05% colchicine mixture was treated,the highest variation rate was16.7%.Therefore,the effect of the apical portion treated by colchicine was the best,followed by the root tip,of which the germinating seeds was the poorest.Orphological identification results showed that the leaves of variant plant were apparently shorter and width,the flower diameter was larger.Anatomy identification results showed that length and width of stomata on variation plant leaves was obviously greater,and density of stomata was smaller,pollen diameter was also larger.Molecular biology identification showed that DNA content analysis on the primaries of the 13 by flow cytometry,11 produced polyploid variation,the total variation rate reached 84.6%,of which 7 were tetraploid,3 octoploid,1 chimera.