Abstract: In order to reveal the characteristics of the“blunt with blossom”cucumbem (BBCs)．we investigated the anatomical and cytological characteristics of the young stems and shoot tips of the BBCs by light microscopy(LM)，transmission electron microscopy(TEM)and scanning electron microscopy(SEM)procedures．In BBCs plants。the node number。internode length and the stem diameter in shoot tops all reduced，and the elongation and expansion of the stem cells were inhibited．In contrast，the wall thickness of the collenchyma cell,the number of the vessel bundles．and the number of mature vessels in young stem increased respectively．Meanwhile，the shoot apical meristem cells avacuoled。and the nuclear envelope，tonoplast，plastid envelope and endoplasmic reticulum dissolved partially．In the studies on the role of BBCs。two positive cDNA bands were obtained through mRNA differential display．Northern blot analysis showed that one cDNA fragment homologous to the chloroplast ATPase subunit III Was down regulated and the other cDNA fragment homologous to the arginine deearboxylase(ADC)was up regulated in BBCs．

Key words: Cucumber, Blunt with blossom, Anatomy, Cytology, mRNA diferential display