THE MOLECULAR BREEDING OF ORNAMENTAL FLOWERING PLANTS; FLOWER COLOR MODIFICATION OF Torenia hybrida

White and blue/white varieties of Torenia hybrida cv. Summerwave (SWB) were successfully obtained from the blue variety of by cosuppressing gene expression of two of the enzymes involved in anthocyanin biosynthesis; chalcone synthase (CHS) and dihydroflavonol 4-reductase (DFR). Such molecular brceding is the only precise and efficient way to widen the flower color variation of SWB due to its male and female sterility. Flower color and the degree of suppression varies depending on the transgenic lines. The dorsal and ventral petal lobes and corolla tube consistently lose anthocyanins prior to lateral petal lobes. A pink variety was also obtained by cosuppressing the flavonoid 3`5`-hydroxylase (F3`5`H) gene. Yellow torenia was obtained from T-33, an in-house cultivar that contained both carotenoids and anthocyanins, by blockage of anthocyanin biosynthesis with cosuppressing CHS or DFR genes.