Blue roses have, for centuries, had an almost mythical stature. Unknown in nature, due to the absence of a gene for producing blue pigment, blue roses have been a symbol of the unattainable and of love and prosperity. For centuries, breeders have tried unsuccessfully to produce a rose with a true blue color. Limited success has been achieved in this pursuit, although the roses are not a true blue color but usually a shade of mauve or lilac. Roses of a true blue color can be produced by dyeing white roses or through the introduction of a gene for blue pigments into existing rose stock through genetic engineering.
The first blue roses were produced by the introduction of a blue dye through the roots. This process was first recorded in 12th century in the Far East. Modern horticulturists have been able to duplicate the process, verifying the historical record. This technique is still in use today.
Blue dye can also be applied directly to the blossoms of white roses, giving them a blue color. These roses can have a vibrant, bright blue color that is normally unavailable in roses. Blue dye or even blue food coloring is dissolved in water and cut roses are placed in the liquid. They will absorb the dye, and the blooms will gradually assume a blue color.
For centuries, breeders and horticulturists have tried to breed blue roses. Until recently, it was not completely understood why this was not possible. Research has shown that roses do not produce a certain type of pigment that produces the blue color. All attempts at producing a blue rose through hybridization and other breeding techniques failed, although breeders have managed to produce roses with a mauve or purplish color, many of which are marketed with names having "blue" in them.
Recently, scientists in Japan from the Suntory Corporation, working with an Australian company, Florigene, produced the world's first genetically engineered blue rose. They spliced in genes from another flower, the petunia. The introduction of this gene allowed the genetically engineered rose to produce delphinidin, a blue pigment. Further work on the DNA of these roses is underway to suppress the production of another pigment, cyanidin, which causes the flowers to have a purplish or mauve color.
