Rosa × kordesii

Rosa × kordesii, or Rosa kordesii, is a red type of rose that arose naturally from hybridization followed by chromosome doubling. A hybrid between R. rugosa and R. lucieae was created called Rosa 'Max Graf', but it was diploid and nearly sterile, producing flowers but no fruit. This rose produced a few viable seeds as a result of self-pollination, and the seedlings that resulted were tetraploid instead of diploid, i.e., the chromosomes of both pollen and egg cells had been naturally duplicated. The tetraploid seedlings are amphidiploids.^[1] A selection with double deep pink flowers and repeat bloom, also called 'K01 AgCan' was released by W. Kordes' Söhne in 1951.^[2]

These tetraploid roses interbreed readily with one another, but not with their diploid ancestors. Under the biological species concept, a new species name Rosa × kordesii was created for the tetraploid hybrid roses and their descendants.^[3]

Amphidiploid roses can also be created deliberately from diploid-diploid hybrids by using colchicine spray on the growing tips of the plants. That strategy gives few successes, however, because the plant tissue has various chromosome numbers in different cells.^[1] Amphidiploid roses including Rosa × kordesii have been used to some degree in breeding programs in combination with naturally occurring tetraploid roses.^[1]

Rosa × kordesii petal extract gel is stable for at least 3–4 months when stored at 5 and 25 °C. It is essential for collection of similar data for different plants and their flowers, as well as other parts. This proved activity of plant showed its importance and prophylactic utility in anti-solar formulation. This will be a better, cheaper and safe alternative to harmful chemical sunscreens that used nowadays in the industry.^[4]