木兰科5个种间杂种减数分裂行为观察

Meiotic Observations on the Pollen Mother Cells of Five Interspecific Hybrids in Magnoliaceae

对木兰科5个二倍体人工杂交后代的减数分裂行为进行观察。结果表明,各杂交F1代的减数分裂行为基本正常,在减数分裂中期I有个别二价体提前分开形成单体;中期I还存在异型二价体,说明杂交亲本间(种间)都有一定的遗传分化,但这种变异仅停留在基因水平上;后期I偶有染色体桥出现。杂种F1代的减数分裂过程基本正常,能形成生活力正常的生殖孢子。可预期的是自然界中木兰科属内种间的自然二倍体杂种可自行繁衍,经过一定繁衍周期后,即可形成具有相对稳定种群的新种。

The meiosis processes of pollen mother cells （PMCs） of five hybrids in Magnoliaceae were observed. The results were shown as follow：the meiosis process was quite normal;some bivalences separated early and formed univalent in MI; there were heteromorphic bivalent in PMCs, which revealed that certain differentiation existed among these parents, but only on the level of genes. The meiosis process is regular and can produce normal spores. On the other word, some nature hybrids can reproduce by themselves in wild, and will form a new species with certain population.