Abstract: To identify IPT family genes in cucumber（Cucumis sativus L.）and investigate the relationship between cucumber fruit development and CsIPT，parthenocarpic line‘EC1’and non-parthenocarpic line‘8419s-1’were used for real-time RT-PCR analyses. Based on the expression patterns of CsIPT in different organs，functional genes involved in fruit development were identified and further analyzed by their expression patterns during fruit development. The results indicated that similarity of eight CsIPT genes were in the range of 17.3%–33.2%，length of amino acids were 280–504 AA. CsIPTs had a common ATP/GTP binding domain of the[(A,G)-X₄-G-K-(S,T)]. CsIPT4 contained putative a zinc finger-like motif（C-X₂-C-X_12,18-H-X₅-H）. CsIPT3，CsIPT5，CsIPT7 and CsIPT8 had higher expression in the early cucumber fruit. In the undeveloped fruit CsIPT1，CsIPT3，CsIPT4 and CsIPT5 showed an significant increasing trend. CsIPT2 and CsIPT8 were related to fruit development after pollination，at the same time the expression of CsIPT2 was higher in the early fruit development of‘EC1’. Therefore，it was speculated that CsIPT2 may participated in the regulation of fruit development in cucumber parthenocarpic line.

Key words: cucumber, Cucumis sativus L., parthenocarpy, isopentenyl-transferases（IPT）, gene expression, quantitative real-time RT-PCR