ABSTRACT
Citrullus is a monoecious or andromonoecious annual, with long runners and deeply pinnatifid leaves. The flowers are yellow with five sepals and corolla deeply parted. Perfect or pistillate flowers appear on the 8th to 12th node of the main stem depending on environmental growing conditions and cvs. Citrullus fruits are large — ranging in weight from 2 to 15 kg in different cvs; their shape can be round, oval, elongated-cylindrical, or ellipsoidal. The information on the genetic regulation of sex expression is limited to perfect or female flower development. The flowering pattern in monoecious or andromonoecious melons is characterized by successive development of staminate and pistillate flowers in leaf axils on the main stem or lateral branches. The role of endogenous ethylene in the regulation of flower bud differentiation in the watermelon should be further elucidated by more direct investigation. Internal ethylene levels are higher in watermelon plants than in other cucurbits.
