玉米小孢子胚胎发生启动的超微结构观察

ULTRASTRUCTURE OBSERVATION OF MAIZE MICROSPORIC EMBRYOGENESIS

利用透射电镜观察了玉米花药培养过程中小孢子胚胎发生启动的超微结构特征，发现培养１ｄ的小孢子细胞器丰富，核仁、核膜清晰；培养３ｄ后，开始进行第１次有丝分裂。不均等分裂以后即在生殖核的外围产生细胞壁，有的线粒体、质体以缢缩方式增殖，表明营养细胞处于代谢活跃状态，有可能进一步发育。

To study the mechanism of maize microsporic embryogenesis the ultrastructural features were observed. The microspores which had finished dedifferentiation contained numerous organelles and clear nucleoli after one day of incubation. The first division occured 3 days after incubation. Cell walls around the generative nuclears formed following asymmetric divisions. The vegetative cytoplasm had more organelles and the fissions of some plastids and mitochondria through the ways of constriction were also observed. This indicated that vegetative cell was in active metabolic status and probably would divide to develop embryoids or callus.