21 October 2024

Thornless roses are the rose fancier’s dream but are difficult to breed, are usually infertile, and require a genetic mutation to block the prickles from emerging on the skin. Because the underlying trigger is still present, new growth on a “thornless” rose can produce prickles at the drop of a hat — injury, root suckers, etc.

What we call “thorns” on roses are technically prickles because they grow out of the skin. Roses, wineberry and devil’s walking stick have the same gene coding for prickles.

What are the genes underlying prickle development? Two studies published in August 2024 investigated Solanum prickle plants (eggplants, tomatoes) and found that they share the same LOG family genes. When scientists disrupted those genes it resulted in prickle loss in multiple species and did not adversely affect other parts of the plant.

Because roses have prickles and may share the same gene coding, there is new hope for creating a truly smooth stemmed rose.

See a summary of the studies in Smithsonian magazine. The two scientific studies are here and here.

p.s. Why are rose thorns actually prickles? Find out at Ohio State University: Armed by Nature: Thorns, Spines, and Prickles