红皮树胚胎发育

本文报道红皮树(Styrax suberifoltus Hook.et Arn.)大小孢子发育和早期胚胎发生。子房具胚珠20—23枚,胚珠横生,珠被二层,薄珠心,孢原细胞直接起大孢子母细胞作用。合点端大孢子具功能。胚囊发育为正常型。成熟胚囊具大量淀粉粒。小孢子形成为同时型,成熟花粉为二细胞型。传粉后、受精前两个助细胞在形状和对苏木精着色程度上有显著区别。胚乳发育为细胞型。在合子分裂前,胚乳细胞增至约26个时,暂时停止分裂。苏木精对细胞质不易着色,似解体细胞。有胚乳吸器。

EMBRYOLOGICAL STUDIES OF STYRAX SUBERIFOLIUS

The present paper deals with the development of male and female gametophytes and the early embryogenesis of Styrax suberifolius. The ovary contains 20-23 ovules. The ovules are hemitropous, with 2 integuments, tenuinucellate and the archesporial cell functions directly as the mega-spore mother cell. The chalazal megaspore is functional. The development of the embryo sac conforms to the normal type. The mature embryo sac is rich in starch grains. The formation of the microspores are of the simultameous type and the mature pollen grain is 2-celled. After pollination and before fertilization the two synergids are obviously different in shape and in staining reaction to haematoxylin. The endosperm is cellular type. Before the division of the zygote the endosperm increases to about 26 cells and then remain at this stage for some time. The cells are not easy to be stained with haemato-xylin and they look like disintegrated cells. The endosperm haustoria are present.