糜子花粉粒和胚囊发育的步调比较

On Comparision of Developmental Processe of Pollen and Embryo sac in Panicum miliaceum L.

本文对糜子的花粉和胚囊发育的步调进行了比较,并对花粉败育进行了形态学观察。小孢子母细胞在花药长度为0.5mm时进入减数分裂,早于大孢母细胞,进程较大孢母细胞的减数分裂慢,四分孢子时期持续时间短,单核花粉时期持续时间长(约72h),从小孢母细胞减数分裂开始到花粉粒成熟约需8d。大孢母细胞的减数分裂迟于小孢母细胞,减数分裂进程速度较快,从单核胚囊开始,稍微加快了发育速度,以此与花粉的成熟取得一致。败育花粉的母细胞能进行正常的减数分裂,但在单核花粉时,由于绒毡层不解体,使其得不到养料,从而停止发育。

Developmental processes of pollen and embryo sac in Panicum miliaceum L. were comparied with each other, and morphotogy of the abortive pollen was abserved in this paper. The microspore mother cell began to get into meiosis when the anther length was 0.5 mm, which was prior to that of the megasporocyte, Meanwhile the process of the meiosis is rather slower than that of megasorcyte, and the tatracl stage lasted a shorter time than that of mono nuclear-pollen(about 72h). It will take eight days from the meiosis to the maturity of pollen. Beginning later, the meiosis of the megasporrocyte is faster, especially when it got into vni-nuclear embryo sac stage, so that it could catch up with the pace of pollens maturity. The mother cells in those pollens with sterility can have normal meiosis. It stops developing due to the deficency of nutrition when it gets into Vninuclear pollen stage when the tapetum is not discomposed.