关键词: 獐牙菜, 胚胎发生, 龙胆科

Abstract: The megasporogenesis, the development of female gametophyte, embryo and endosperm of Swertia bimaculata were studied. The main results can be concluded as follows: The ovary is bicarpellate, unilocular with 4 rows of ovules located at the parietal placentation. The ovule is unitegmic, tenuinucellar and ana-campylotropous. The chalazal megaspore in linear tetrad becomes the functional megaspore. The development of embryo sac is of the Polygonum type. Three antipodal cells have multiseriate nuclei and distinct haustorium, and persist like a layer of “outer endosperm” just out of the endosperm nucleus layer. Fertilization is porogamous and of premitotic syngamy type. The development of endosperm conforms to Nuclear type and the embryogeny corresponds to the Solanad type. The embryo is at the globular stage when seeds are released from the capsule. The dividing and persisting of antipodal cell in some annual Gentianaceous plants is of significance in reproductive adaptation and evolution.

Key words: Swertia bimaculata, embryogenesis, Gentianaceae