The causes of the interspecific and intergeneric incompatibility of a few bromeliad species will be examined. Therefore we will use an anatomical and physiological approach. The anatomical research intends to get insight on the fertilization apparatus anatomy, and the morphology of micro- and macrospores and the embryo development. The pollen maturation and outgrowth, the ovule lifetime and embryo development will be studied in vitro and/or in vivo for compatible and incompatible crosses. The influence of cultivation conditions of parent plants before and during anthesis, and development and outgrowth of embryo's will be evaluated. Further research will be aimed at finding solutions and work on techniques to overcome the detected incompatibility. This fundamental knowledge will allow us to creat new crosses which are impossible without this.