Abstract: Rhizobium pp. isolated from rice nodules induced rice root hair expanding, curling and branching. Rice nodule primordium was found 25 d after inoculation. Many small nodular structures were produced 30-40 d after inoculation. Most of these structures could not further develop and die. Different kinds of culture media affected the initiation and development of rice nodular structure, soil was the best. The cellular structure of rice nodules was similal to that of legume nodules. The infected cells were connected with vascular bundles by cortex. The infected cells were full of bacteria.

Key words: Nodule development, Rhizobium, Rice nodular structure

关键词: 根瘤发育, 结构, 水稻, 根瘤菌