Perspective Chapter: Creation and Evolution of Intergeneric Hybrids between Brassica rapa and Raphanus sativus

Although research has been conducted on intergeneric hybridization between Brassica and Raphanus, much of it remains unpublished. We have acquired numerous Brassica rapa ssp. pekinensis (kimchi cabbage) and R. sativus var. major (“big root radish”) hybrids, originally classified as intergeneric hybrids and named “baechumu” in 1995. A cultivar was identified BB#12, (renamed BB#1 for registration) in baemoochae following stabilization via a microspore mutation in 2006. Numerous hybrids were created for various purposes; some were sterile when self-pollinated but fertile in crosses with other cultivars. Microspore mutation also produced, BB#12x is a novel intergeneric hybrid. A new stable plant variety, BB#5, was selected from numerous inbred lines and produced via microspore culture; it has a very late bolting time and is cultivated in spring. The cultivar purple BB#10 was developed by adding radish chromosomes to turnip, including one providing the purple color, and double-crossing with BB#12, CMS BB#12, and normal BB#12. Now that the hybrid between ssp. pekinensis and radish has produced mature seeds as a dominant property, intergeneric hybrid cultivars can be bred in the future.