Abstract: The genesis and development of Nelumbo nucifera root and root system in ontogeny and their adaptation were studied in this paper. The shoot end develops be fore root end and the node-roots arise from the first node of plumule before the radicle. Very few "seeds" weakly develop a radicle primordium when the seed germinate, but it is never seen that the radicle stretches out of "seed"-coat. The fibrous root system only consists of node-roots and the root end doesn' t develop into a taproot system all its life. That should be named as proto-fibrous-root-system. This This project supported by Heilongjiang Province Natural science Foundation of China root system died within one growing season is new development type, it is named as annual total renewed type. In the 4 nodes of seedling the stem is erect and the leaf is altemate, and then the stem is creeping and the leaf is assembling. For the above facts we considered that the creeping stem and first developing nede-roots are correlative with water enviromnt and the erect stem and weakly developing radicle are coitelative with tervestrial enviromnt. All these characters are both adaptive and hereditary.

Key words: Nelumbo nucifera, root, root-system, ontegeny, adaptation