AN IN-VITRO SYSTEM FOR ADHESION AND FUSION OF MAIZE GAMETES

The development of in vitro fertilization systems in flowering plants is important for understanding and controlling the mechanisms of ferti lization. Here a method is described in which isolated maize gametes f use. In a medium containing 5 mM calcium chloride, sperm and egg cells adhere for several minutes and then fuse within 10 seconds. The metho d is specific to male-female gamete pairs and results in 80 percent fu sion, whereas fusions with other combinations of gametic and mesophyll ic cells are less frequent. Eggs fertilized in vitro do not fuse with additional male gametes, which suggests that a block to polyspermy exi sts.