关键词: 黄瓜, 霜霉病, 抑制差减杂交, 抗性相关基因

Abstract: In order to identify the genes associated with cucumber（Cucumis sativus L.）resistance against Pseudoperonospora cubensis（Berk. and Curk.）Rostov.，two cDNA libraries were constructed by suppression subtractive hybridization（SSH）. After differential screening by reverse northern dot blot hybridization，sequencing and BLAST，2I15（GD254229），3C19（GD254243）and 1O08（GD254207）differential expressed genes with unknown function were isolated，furthermore，expression patterns of the genes were monitored by real-time quantitative RT-PCR. The results indicated that these genes were differentially up-regulated earlier and more quantitative in the resistant inbred line than the susceptible inbred line. Moreover，1O08 and 2I15 could be differentially up- or down- regulated，respectively，by salicylic acid（SA)，jasmonic acid（JA）and abscissic acid（ABA)，and 3C19 could be induced or suppressed significantly by ABA and SA，respectively. Mechanical wounding，NaCl stresses，cold and heat shock could induce or suppress these genes differential expression，suggesting that these genes may have some functions involved in biotic and abiotic stresses.

Key words: cucumber, downy mildew, suppression subtractive hybridization, resistance-related genes