鸭跖草科杜若(Pollia japonica Thunb.)的减数分裂研究

Meiosis Studies of Pollia japonica Thunb. (Commelinaceae)

首次对鸭跖草科杜若(Pollia japonicaThunb.)进行了花粉母细胞减数分裂观察,并重新报道了该种的染色体数目为2n=32。结果显示,减数分裂中期I构型为16Ⅱ,并且观察到次级联会现象。减数分裂后期I和后期Ⅱ存在落后染色体、染色体断片、二次分裂不同步等异常现象,统计各时期畸形率都低于10%。随机统计花粉粒活性,成熟率达到90%以上。这说明杜若的减数分裂过程基本正常,也证明了2n=32的体细胞染色体数目是可信的。

In this paper, the meiotic process of pollen mother cells and the somatic chromosome number 2n = 32 of Pollia japonica Thunb. （Commelinaceae） are reported for the first time. The chromosomes in metaphase Ⅰ possess the configuration of 16 Ⅱ and the secondary association has also been observed. During anaphase Ⅰ and anaphase Ⅱ, lagging chromosomes, chromosomal fragments and asynchronism have been observed and the abnormality rates of both phases are less than 10%. The rate of fertile pollen grains is more than 90%, which is consistent with the cell abnormality rate at anaphase Ⅱ. These results indicate that meiotic process of this species is normal, and the somatic chromosome number 2n = 32 is credible.