【摘要】 观察了柳杉雌、雄配子体的发育,受精和胚胎的发育。3月中旬珠心内一个具功能的大孢子细胞核开始分裂,形成雌配子体。约分裂至3000—4000个游离核时,逐渐向心形成细胞壁。5月中下旬,在雌配子体珠孔端形成由12—16个颈卵器组成的复合颈卵器。以单核花粉3月初传粉,4月下旬花粉萌发。花粉管伸出后,胚性细胞分裂形成生殖细胞和管细胞,生殖细胞再分裂形成不育细胞和精原细胞。5月中旬,管细胞和不育细胞消失,精原细胞分裂形成2个精子。受精卵分裂3次,形成8个游离核,排列为两层,上层为5或6个核的开放层,下面为3或2个初生胚细胞。开放层再分裂一次,产生5—6个上层细胞和5—6个原胚柄细胞,形成标准型原胚(按Doyle,1963)。6月上旬原胚发展成圆柱形的后期胚胎,9月胚成熟。成熟胚一般由胚根、胚轴、胚芽和3枚子叶组成。更多还原

【Abstract】 The embryogeny of Cryptomeria fortunei was observed. By the middle of March the nucleus of functioning megaspore divides twelve times to form about 3000—4000 free nuclear female gametophyte. Wall formation is centripetal. By the end of May the archegonial complex containing 12—16 archegonia surrounded by jacket layer is present at the micropylar end of the gametophyte. The pollen grains are shed at the uninucleate stage. After pollination the pollen grains swell. The microspore nucleus moves to one side and divides to form a large generative nucleus and a small tube nucleus. The generative cell then divides to form a body cell and a stalk cell. When the pollen tube passed through the nucellus and reached the archegonial complex the nucleus of the body cell divides to form two male cells, generally only one of which enters the archegonium and the fertilization takes place in the upper part of an egg cell. A number of eggs in an archegonial complex may be fertilized. After the fusion of the male nucleus with the egg nucleus, the zygote divides three times to form eight nuclei, which become organized into primary embryo cells and the open tier. The former are only two or three cells, while the latter has five or six cells open towards the top and divides to form the prosuspensor tier and the upper tier. Thus, the pro-embryo of Cryptomeria belongs to the standard type, according to Doyle (1963). Excepting the simple polyembryony, the cleavage polyembryony is a common character in the embryogeny of Cryptomeria. The mature embryo consists of the radicle, the hypocotyl, the plumule and three cotyledons. When the embryogeny of Cryptomeria fortunei is compared with that of C. japonica, there are many differences obtained. The number of archegonia in the archegonial complex of C. fortunei is less than that of C. japonica. The former does not form the archegonial chamber and the chalazal and lateral archegonia, while the latter does.更多还原