Abstract: The muskmelon (Cucumis melo L.var. reticulatus Naud.) varity ‘Xi Yu No.1’ was treated with 150 mg·L^-1 ethephon at appearance of the fourth euphylis，in this study in order to induce the formation of bisexual flowers in main vine，materials treated with fresh water was used as control. The flower buds were extracted from main and lateral vine of control and treated seedlings at different stages，then their differentiation processes were observed from morphological and anatomical viewpoints. The results showed that the flower primordium in main vine of seedlings，which were treated with ethephon differentiated into bisexual flower sustainably and formed bisexual flower at last. The flower primordium in main vine of untreated seedlings had the same differentiation process with bisexual flowers at early stage. After the appearance of pistill development was stopped and male flowes were finally formed. The development process of bisexual flowers in main vine of treated seedlings was the same as the bisexual flowers in lateral vine.

Key words: muskmelon(Cucumis melo L.var. reticulatus Naud.), ethephon, flower bud differentiation, morphology, anatomy