Preliminary study on the root nodule formation of the legume plant

The root nodule of the legume plant's ability of nitrogen fixation from air makes it grow in the poor soil very well.The formation of nodule needs both legume plant and the rhizobia,that from soil or cultural medium.However,the nodule could be induced by germfree liquid that filtered from the rhizobia,cultural medium.It is proposed that the some soluble substances excreted by the cultured rhizobia,can stimulate the plant to form the root nodules.Nevertheless,the nodules formed by this way can't produce haemachrome.So the nodules show light green or white.And there are starch in them.We observe process of the root nodules formation by inoculating the rhizobia,and the germfree filtrate;and analysis the results in this paper.