Genetic mapping of ripening and ethylene-related loci in tomato

The regulation of tomato fruit development and ripening is influenced by a large number of loci as demonstrated by the number of existing non-allelic fruit development mutations and a multitude of genes showing ripening-relat ed expression patterns. Furthermore, analysis of transgenic and naturally o ccurring tomato mutants confirms the pivotal role of the gaseous hormone et hylene in the regulation of climacteric ripening. Here we report RFLP mappi ng of 32 independent tomato loci corresponding to genes known or hypothesiz ed to influence fruit ripening and/or ethylene response. Mapped ethylene-re sponse sequences fall into the categories of genes involved in either hormo ne biosynthesis or perception, while additional ripening-related genes incl ude those involved in cell-wall metabolism and pigment biosynthesis. The pl acement of ripening and ethylene-response loci on the tomato RFLP map will facilitate both the identification and exclusion of candidate gene sequence s corresponding to identified single gene and quantitative trait loci contr ibuting to fruit development and ethylene response.