Abstract: To indentify the RDR genes and their expression characteristics involved in the root-knot development of cucumber（Cucumis sativus L.），RT-PCR and qPCR approaches were used in this study. Five CsRDR genes were isolated from root-knot of cucumber via RT-PCR，including CsRDR1a，CsRDR1b，CsRDR1c，CsRDR2 and CsRDR6（GenBank No. HQ738485–HQ738489）. qPCR analysis showed that the expression of five CsRDR genes were increased at different levels in different stages upon Meloidogyne incognita infection. CsRDR1a，CsRDR1b，CsRDR2 and CsRDR6 displayed a significant increase in expression at the early stage（6 hours after M. incognita infection），while the expression of CsRDR1c was enhanced at 36 hours after the inoculation. The results revealed that CsRDR genes were related to the root-knot development of Cucumis sativus，which laid a foundation for the prevention of root-knot nematode through molecular breeding technology.

Key words: Cucumis sativus, root-knot, RDR, isolation, expression