Fruits play a central role in agriculture since they are the harvested product for many plant species. It is likely that the functional understanding of fruit development genes in the model plant system of Arabidopsis will be directly transferable to crop plants, and thus this research should facilitate gene discovery in plants of agricultural importance. Fruit size, shape, and method of seed dispersal varies markedly in different species, but the molecular and genetic basis of this diversity is completely unknown. The central issue addressed involves the identification of the major genes that are required for normal fruit development. A number of genes that control the formation of the different parts of the fruit will be identified and these genes are important for fruit size, shape and seed dispersal. A series of genetic and molecular approaches are proposed to identify and characterize additional genes that regulate the upstream patterning processes that control fruit development. These studies should lead to a simple model for the action of major genes in controlling fruit development and this model should be generally applicable to many species. This research will also provide excellent training opportunities for students and postdoctoral fellows. The resources created will be incorporated into laboratory courses and outreach efforts.