【摘要】 对白蚰包及泰山1号两个小麦品种的花粉和胚囊的发育及其进程进行了系统观察与比较。大多数花的胚囊母细胞与花粉母细胞同时开始减数分裂,自细线期后,胚囊母细胞的减数分裂均慢于花粉母细胞,但最后雌、雄配子体却同时成熟。雌、雄两性细胞同时发育成熟,并不主要取决于二者的减数分裂的同步与否,还在于雌、雄配子体的形成过程中,两者有丝分裂周期长短不同,雌、雄配子发生的时间不同及二者成熟所需的时间不同,调节了两性发育的步伐,达到了两性的协调,以适于白花传粉。更多还原

【Abstract】 Bai You boa and Tai shan No.1 were used for studying the micro- and mega-sporocytic meiosis as well as the pollen and embryo sac de- velopment in wheat (Triticum aestivum L.).Attention was also paid to revealing the relationships between these events. In most florets,meiosis of PMCs and EMC in the same floret start- ed concurrently,but after leptotene,the latter proceeded more slowly than the former. When the embryo sacs were found with one,two,four or eight nuc- lei,most pollen grains within the anthers of the same floret had asin- gle and eccentrical nucleus.As the embryo sac of a floret reached the 7-celled stage,the pollen grains generally advanced to the state ei- ther with a single and eccentrical nucleus or at P.G.M.1 or with two nuclei.By the time the embryo sac developed to the stage of prolife- rating antipodal cells,pollen grains were found to be 2-nucleated. when the embryo sac became mature,pollen grains developed into 3- nucleate stage (which is also an indication of pollen maturation). The development of pollen grains from microspores takes much longer than that of the embryo sac from megaspores.The embryo sac and the pollen grains are ingeniously regulated to mature at the same time so as to facilate self-pollination.更多还原