Abstract：Taking bulb shoot tips of purple garlic（Allium sativum L.）Z-006-10 passed physiological dormancy as experimental material，using in vitro induction method by adding Amiprophos-methyl into solid culture，studied the induction effect of Amiprophos-methyl on chromosome of somatic cell at different concentration and with different treated durations．The ploidy level was identified by morphological trait，chromosome number and flow cytometry techniques．The results indicated that the treatment with 10 μmol?L-1 Amiprophos-methyl for 6 d，the induction rate of tetraploid reached the highest-32.87%．The morphological trait showed that the tetraploid plants showed obviously morphological characteristics and were remarkably differed from diploid plants．The chromosome observation of root tips showed that the choromosome number of tetraploids was 2n=4x=32，while the control was 2n=2x=16．The ploidy analysis by flow cytometry verified that the relative DNA content of tetraploid somatic cell was twice the diploids，which was accorded with that of chromosome analysis.
