Objective: To identify tetraploid Isatis indigotica strains through morphology and flow cytometry.
Methods: The tissue culture seedlings of tetraploid Isatis indigotica were root-tip squashed and chromosome counted before rooted climatized and transplanted in field. The plants in field were taken as experimental materials. Macroscopic observation was applied to identify by form and structure; Free-hand section was used to observe the length, width and density of stomas; And flow cytometry was applied to identify the ploidy.
Results: Compared with diploid plants, tetraploid plants had obvious changes in form and structure. The stomas from the tetraploid were notably longer, and the number of guard cells in chloroplasts was remarkably larger. The experiment materials were proved to be tetraploid by flow cytometry.
Conclusion: The materials are tetraploid plants. Macroscopic observation, the length of stoma and the number of guard cells in chloroplasts can be taken as aided identification for ploidy of mutagenesis materials. Meanwhile, flow cytometry can be applied to identify the ploidy of Isatis indigotica.