Over the years, breeders have focused on creating hybrids that are hardy, disease resistant, and with pretty petals. Unfortunately, in the process, fragrance was actually bred out of most of these varieties. Scientists believe there is a compatibility issue between genes that are disease resistant and genes that create fragrance. In cultivated roses, scent has no reproductive function, so if commercial roses lose their scent, it has no impact on the livelihood of the variety. This may be OK for growers, whose main goal is to get a quality stem to a florist, however, the consumer feels cheated. Fragrance, afterall, is the soul of the rose.
Wild roses could not survive without their scent because it attracts bees and other insects that pollinate its flowers. Without this natural pollination, the variety would die out. Wild roses genetically evolve to keep producing scent.
In 2018, a team of international researchers completed the successful mapping of an heirloom rose's genome. This was no small feat, as the process took eight years. They now know where the bud's color and scent come from, and how to tweak those traits to yield a more fragrant flower. Researchers specifically identified an enzyme, known as RhNUDX1, which plays a key role in producing the flowers' sweet fragrances. They have found that this enzyme, which acts in the cells located in the flower's petals, generates the fragrant and well-known monoterpene geraniol, the primary part of rose oil.
Breeders are already working diligently to develop hardy and fragrant new varieties of cultivated roses for the cut floral industry. However, developing a new variety takes up to 10 years, so it won't happen quickly. The good news is we have much to look forward to.