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Brassicoraphanus is any intergeneric hybrid between the genera Brassica (cabbages, etc.) and Raphanus (radish). The name comes from the combination of the genus names. Both diploid hybrids and allopolyploid hybrids are known and share this name.

Early experimental crosses between species of these two genera had been sterile or nearly sterile, but large-scale experiments by Soviet agronomist Georgi Dmitrievich Karpechenko using Raphanus sativus and Brassica oleracea were remarkable because some of the plants produced hundreds of seeds. The second generation were allopolyploids, the result of gametes with doubled chromosome numbers.

• P0: Raphanus ${\displaystyle 2n_{R}=18}$ x, a new crop in agriculture Brassica ${\displaystyle 2n_{B}=18}$

• F1: sterile hybrid ${\displaystyle n_{R}+n_{B}}$
• Some of F1 spontaneously doubles their ploidy, resulting in the fertile allopolyploid ${\displaystyle 2n_{R}+2n_{B}}$

As Karpechenko realized, this process had created a new species, and it could justifiably be called a new genus, and proposed the name Raphanobrassica for them, but the earlier name Brassicoraphanus has priority. Plants of this parentage are now known as radicole.

Karpechenko wanted a plant with leaves of a cabbage and the roots of a radish, but got the opposite. It is useful as fodder for livestocks, but not humans.

Two other fertile forms of Brassicoraphanus are known by the following informal names:

• The Raparadish group are allopolyploid hybrids between Raphanus sativus and Brassica rapa, used as fodder crops
• The Radicole group are allopolyploid hybrids between Raphanus sativus and Brassica oleracea, used as fodder crops
• Raphanofortii is the allopolyploid hybrid between Brassica tournefortii and Raphanus caudatus

Currently, it is thought that a great part of the flowering plants have some hybridization and polyploidization among their ancestors.

References

1. Karpechenko, G. D. (December 1928). "Polyploid hybrids of Raphanus sativus X Brassica oleracea L.". Bulletin of Applied Botany. 17: 305–408.
2. Karpechenko, G. D. (1989) . "Polyploid hybrids of Raphanus sativus L. X Brassica oleracea L.". In Janick, J. (ed.). Classic papers in horticultural science. The Blackburn Press. pp. 442–525. ISBN 9781930665064.
3. Karpechenko, G. D. (December 1928). "Polyploid hybrids of Raphanus sativus X Brassica oleracea L.". Zeitschrift für Induktive Abstammungs- und Vererbungslehre. 48 (1): 1–85. doi:10.1007/bf01740955. ISSN 1617-4615. S2CID 116381242.
4. Shemilt, L. W., ed. (1983). Chemistry and world food supplies : the new frontiers, Chemrawn II : invited papers presented at the International Conference on Chemistry and World Food Supplies, Manila, Philippines, 6-10 December 1982 (1st ed.). Oxford: Pergamon Press. p. 573. ISBN 0080292437. OCLC 9557528.
5. Meneely, Philip Mark; Dawes Hoang, Rachel; Okeke, Iruka N.; Heston, Katherine (2017). Genetics: genes, genomes, and evolution. Oxford: Oxford University Press. p. 249. ISBN 978-0-19-879536-0. OCLC 951645141.
6. Choudhary, B. R.; Joshi, P.; Singh, K. (2000-10-10). "Synthesis, morphology and cytogenetics of Raphanofortii (TTRR, 2n = 38): a new amphidiploid of hybrid Brassica tournefortii (TT, 2n = 20) × Raphanus caudatus (RR, 2n=18)". Theoretical and Applied Genetics. 101 (5–6): 990–999. doi:10.1007/s001220051572. ISSN 0040-5752. S2CID 22139768.
7. Otto, Sarah P.; Whitton, Jeannette (2000). "Polyploidy: incidence and evolution". Annual Review of Genetics. 34: 401–437. doi:10.1146/annurev.genet.34.1.401. PMID 11092833.

Bibliography

• Terasawa, Y. (1933). "Crossing between Brassico-raphanus and B. chinensis and Raphanus sativus". Japanese Journal of Genetics. 8 (4): 229–230. doi:10.1266/jjg.8.229.
• Lee, Soo-Seong; Lee, Sun-Ae; Yang, Jungmin; Kim, Jongkee (2010-11-27). "Developing stable progenies of ×Brassicoraphanus, an intergeneric allopolyploid between Brassica rapa and Raphanus sativus, through induced mutation using microspore culture". Theoretical and Applied Genetics. 122 (5): 885–891. doi:10.1007/s00122-010-1494-3. ISSN 0040-5752. PMID 21113703. S2CID 22306496.

External links

• Observed Instances of Speciation

• Brassicaceae
• Brassicaceae genera
• Speciation events
• Soviet inventions
• Russian inventions
• Plant nothogenera