红直獐牙菜的胚胎学

首次报道了红直獐牙菜大小孢子发生，雌雄配子体形成和胚胎发育过程。主要结果如下：花药四室，药壁发育为双子叶型，绒毡层异型起源，接近腺质绒毡层，中层３层，花药壁表皮宿存，细胞柱状伸长，纤维状加厚，药室内壁退化，小孢子母细胞减数分裂为同时型，四分体的排列方式为四面体形；成熟花粉为３－细胞；子房２心皮，１室，１２列胚珠，侧膜胎座，薄珠心，单珠被，倒生胚珠，蓼型胚囊，反足细胞３个，宿存时间短，胚乳发育为核型

EMBRYOLOGY OF SWERTIA ERYTHROSTICTA MAXIM.

The present paper firstly reports the development of microsporangium,male gametophyte,megasporogenesis,female gametophyte and embryogeny in Swertia erythrosticta Maxim.The main results are as follows:The anther is tetrasporangiate and its wall development conforms to the Dicotyledonous type and comprises of epidermis,endothecium,three middle layers and tapetum at the mature stage.Three middle layers are ephemeral; endothecium reduces and epidermis persists and develops fibrous thickening.The tapetum has dual origin and is more similar to glandular type for the degenerating tapetum nuclei in the middle of anther locule are from the early intruding dividing of the tapetum.Cytokinesis is of the simultaneous type and microspore tetrads are mainly tetrahedral.Pollen grains are mainly 3 celled when shed.The ovary is bicarpellate,unilocular with about twelve series of ovules located at the parietal placentation.The ovule is unitegmic,tenuinucellate and anatropous.The development of embryo sac is of the Polygonum type.Three antipodal cells persist for a short time.The development of endosperms conforms to nuclear type and the embryogeny corresponds to the Physalis I variation of Soland type.The embryo is at the late early heart shaped stage when seeds released from the capsule.The reprofuction and reproductive adaptation of this species are also discussed.