Tetraploidization of hybrid "Raphanobrassica"

    Artificial hybridization of radish (Raphanus) and cabbage (Brassica) (both 2N = 18) produces a sterile first-generation hybrid with one diploid chromosome set from either parent. Tetraploidization eventually produces a stable, true-breeding hybrid (Raphanobrassica). (Unfortunately, the hybrid combines the root of a cabbage with the flower head of a radish, rather than the desired reverse!)