芡个体发育早期的研究

本文研究了芡个体发育的早期, 即心形胚至种苗。心形胚至成熟胚表现为:苗端先发育, 根端弱育;胚芽叶节上的节生根原基先发育, 根端无明显分化。种子胚至种苗表现为:种子萌发时, 下胚轴末端产生多细胞分枝下胚轴毛;种苗形成中, 节生根先发育, 胚根后发育, 且长达1mm左右即停止生长。这些器官发育顺序上的特点在被子植物中是很特殊的, 应该是系统发生上的原始性状。下胚轴毛是水生或湿生被子植物比较普遍的性状, 是区分下胚轴与胚根的指示性状。

STUDY ON THE EARLY STATE OF ONTOGENY OF EURYALE FEROX SALISB.

The early stage(from heart shape embryo to seedling) of ontogeny of Eurgale ferox Salisb.is presented in this paper. The embryo from heart stage to mature stage is expressed as the shoot apex develops firstly and the root apex develops very weakly, at the nodes of lst and 2nd plumular leaves some nodal root primordia develop before radicle and there is no obvious differentiation in radicle.The characters expressed from seed embryo to seedling are as follows. When the seed germinates,4 polyseriate branched hairs arise from the end of the very short hypocotyl. At seedling stage, nodal roots develop before radicle and the growth of the radicle ceases only about 1mm long. These characters of developmental sequence on organogeny are very peculiar to anqiosperms and should be primitive in phylogeny. The hypocotyl hair may be is a general character in aquatic or hygrophytic angiosperms and a indicative character to differentiate radicle and hypocotyl.