分别以桔梗根尖和花粉为材料，通过压片法确定桔梗的染色体数目，观察花粉母细胞减数分裂行为。结果表明，桔梗的染色体数目为2n=18，染色体基数x=9。桔梗花粉母细胞减数分裂过程中，绝大多数细胞分裂正常，极个别细胞在后期Ⅰ出现染色体桥，后期Ⅱ出现不均等分离等现象。

In this paper， The chromosome number of Platycodon grandiflorum are investigated with conventional plant root tip squashing method and studied on its meiosis course of pollen mother cell. The result shows that the chromosome number is 18 and its basic chromosome number is 9. In the meiosis course of pollen mother cell on Platycodon grandiflorum， the most of cell division is normal， but we found some special Phenomenon in a small number of cells， such as chromosome bridge in anaphaseⅠand unequal separation of chromosome in metaphaseⅡ， and so on.

S567.23

山西省科技攻关项目(20130311004-1)。