韭菜胚囊发育与胚胎发生

韭菜胚囊发育为葱型,胚胎发生属柳叶菜型。成熟胚囊中,三个反足细胞形态上常类似卵器,其中二个呈助细胞状,一个呈卵细胞状。卵状反足细胞可分裂成多细胞原胚,但随着胚乳的发育而退化。在未受精胚囊中,卵细胞和卵状反足细胞均可分裂,它们的发生过程与合子胚相似,但因无胚乳哺育,均不能继续发育。论证了反足细胞胚的性质,初步探讨了胚乳与反足细胞无配子生殖的关系。

EMBRYO SAC DEVELOPMENT AND EMBRYOGENY IN ALLIUM TUBEROSUM

The development of the embryo sac of Allium tuberosum belongs to Allium type. In mature embryo sac, three antipodal cells often resemble to egg apparatus: two are like synergids and one is alike to egg cell. The type of embryogeny is Onagrad with the embryo proper principally derived from the apical cell of 2-celled proembryo The egg-like antipodal cells may divide and form multicellular proembryos which degenerate with the development of endosperm, indicating that the latter may exhibit an inhibiting effect to the antipodal proembryos. In some unfertilized embryo sacs, egg cell and egg-like antipodal cell may also divide, they are similar to zygote in embryogeny. However, these proembryos can not continue to develop because of absence of endosperm to nurse them. The concept of antipodal embryo and the relationship of antipodal apogamy with endosperm are discussed.