羊草(Aneurolepidium chinense)的双受精作用与胚胎发育

Double Fertilization and Development of Embryo in Aneurole pidium chinense

本文以采用电镜制片的方法对羊草的双受精过程和胚胎发育进行了研究。羊草的双受精属有丝分裂前配子配合型。开花后约4h精子进入胚囊。两精子几乎同时进卵核和极核之一,精核分别在卵核和极核内松散,同时出现1到2个雄核仁。合子时期雌雄性核仁不融合,直到合子分裂前期仍为多核仁。羊草胚胎发育为紫菀型。一般合子第一次分裂为横分裂,但偶见有斜分裂。合子未见有极性,在二细胞原胚后期见有极性表现,超微结构显示,顶细胞和基细胞中圆球体大小和发育时期不同。胚发育经过原胚、椭圆形胚,再经胚分化期和成熟期发育为成熟胚。

The double fertilization is the tape of the premitotic syngame.In about 4 hours after blossom, the sperms entry the embryo sac.Two male nuclei entry the egg nucleus and one of the polar nuclei almost at the same time, as the chromatin of the sperm n uclei is relaxing in the egg nucleus and the polar nucleus respectively,one or two male nucleoli appear.The male and the female nucleoli do not fuse with each other in zygote. The embryogeny conforms to Asterad type.Generally,the frist division of the zygote is transversally occasionally,is obliquely. During the dormency stage of the zygote, there is no polarity in it.The polarity appears just in the 2-celled proembryo.The embryo development goes through the following stages:proembryo,ellipsoidal,differantiation and mature.