Callus polyploidy induction and identification of Russian wild ryegrass.

Chromosome doubling of Russian wild rye was induced with colchicine and dimethyl sulfoxide(DMSO) in suspension culture media,and embryogenic calli were induced from immature embryos.Chromosome ploidy of root tip cells was identified after induction.Treatment with 100 mg/L colchicine and 1.5% DMSO for 72 h on callus was the best for polyploidy induction.The percentage of tetraploid cells was 53.58%.Morphological comparisons showed that the length and width of leaves from tetraploid plant was increased.The length of stomatal guard cells of the tetraploids increased by 13.52% more than the diploids and the distance between stomata increased significantly.The stomatal characteristics of mixedploid plants were intermediate between the two.