, Volume 32, Issue 2, pp 415–423 | Cite as

The stabilization of chromosome numbers and the maintenance of euploidy in Brassicoraphanus

  • M. Kato
  • S. Tokumasu


To examine whether chromosome numbers of Brassicoraphanus (amphidiploids between Brassica japonicaSieb. and Raphanus sativus L.) are stable or not, the following four items were studied with some plants during the 2nd–11th generations: (1) chromosome numbers of open-pollinated progenies from eu-, hyper-, and hypoploids, (2) chromosome distribution at metaphase II in these plants, (3) frequency of euploids in relation to flower colour and generation, (4) seed fertility in eu-and aneuploids in relation to flower colour. In early generations, hyper-and hypoploids were frequently produced from euploids. In later generations, however, the chromosome number became less unstable. In euploids (2n=38), chromosome numbers at metaphase II showed some variation, and the mean frequency of the euploid chromosome number (n=19) was approximately 78%. This value was almost the same in white-and yellow-flowered plants through early and late generations. Nevertheless, yellow-flowered plants tended to produce euploids more frequently than did white-flowered ones. It is assumed that the difference in euploid productivity between yellow-and white-flowered plants is due to the difference in seed fertility between them. The progeny of each hypoploid showed higher chromosome numbers than their parents. The progeny of each hyperploid showed lower chromosome numbers than their parents: they were approaching to euploidy. This phenomenon, together with higher fertility of euploids and lower fertility of aneuploids, will favor the maintenance of euploidy of this strain.

Index words

Brassicoraphanus chromosome number aneuploid flower colour 


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  1. Ellerström, S. & L. Zagorcheva, 1977. Sterility and apomictic embryo-sac formation in Raphonobrassica. Hereditas 87: 107–120.Google Scholar
  2. Fukushima, E. & S. Iwasa, 1964. A spontaneous haploid plant in a certain Brassico-Raphanus hybrid strain. Proc. Jap. Acad. 40: 232–235.Google Scholar
  3. Fukushima, E. & S. Tokumasu, 1957. On the occurrence of aneuploidy in the offspring of the artificially induced auto-tetraploid plants in Japanese radish (Raphanus sativus L.) and Chinese cabbage (Brassica pekinesis Rupr.). Jour. Fac. Agr. Kyushu Univ. 11: 1–23.Google Scholar
  4. Honma, S. & O. Heeckt, 1962. Investigations of F1 and F2 hybrids between Brassica oleracea var. acephala and Raphanus sativus. Euphytica 11: 177–180.Google Scholar
  5. Howard, H. W., 1938. The fertility of amphidiploids from the cross Raphanus sativus x Brassica oleracea. L J. Genet. 36: 239–273.Google Scholar
  6. Karpechenko, G. D., 1928. Polyploid hybrids of Raphanus sativus L. x Brassica oleracea L. (On the problem of experimental species formation). Z. indukt. Abstamm. u. VererbLehre 48: 1–85.Google Scholar
  7. Karpechenko, G. D., 1929. Konstantwerden von Art-und Gattungsbastarden durch Verdoppelung der Chromosomenkomplexe. Der Züchter 5: 133–140.Google Scholar
  8. Kato, M. & S. Tokumasu, 1976. The mechanism of increased seed fertility accompanied with the change of flower colour in Brassicoraphanus. Euphytica 25: 761–767.Google Scholar
  9. Kato, M. & S. Tokumasu, 1979a. An electrophoretic study of esterase and peroxidase isozymes in Brassicoraphanus. Euphytica 28: 339–349.Google Scholar
  10. Kato, M. & S. Tokumasu, 1979b. Change of cross-affinity with parental species accompanied with the change of flower colour in Brassicoraphanus. Eucarpia Cruciferae Newsletter 4: 34.Google Scholar
  11. Kato, M. & S. Tokumasu, 1980. Nucleus substitution of Brassica japonica Sieb. with Raphanus sativus L. and its resultant chlorophyl deficiency. Euphytica 29: 97–106.Google Scholar
  12. Kondo, N., 1942. A new Raphanobrassica from the cross, 4x-Raphanus sativus L. x 4x-Brassica oleracea L. Jap. J. Genet. 18: 126–130.Google Scholar
  13. McNaughton, I. H., 1973. Synthesis and sterility of Raphanobrassica. Euphitica 22: 70–88.Google Scholar
  14. Mizushima, U., 1952. Karyo-genetical studies on Brassiceae. Gihodo, Tokyo.Google Scholar
  15. Richharia, R. H., 1937. Cytological investigation of Raphanus sativus, Brassica oleracea, and their F1 and F2 hybrids. J. Genet. 34: 19–44.Google Scholar
  16. Terasawa, Y. & N. Shimotomai, 1928. Bastardierungsversuche bei Brassica und Raphanus. Sci. Rep. Tohoku Imp. Univ. Ser 4, 3: 827–841.Google Scholar
  17. Terasawa, Y., 1932. Tetraploide Bastarde von Brassica chinensis L. x Raphanus sativus L. Jap. J. Genet. 7: 183–185.Google Scholar
  18. Terasawa, Y., 1933. Crossing between Brassico-raphanus and B. chinensis and Raphanus sativus. Jap. J. Genet. 8: 229–230.Google Scholar
  19. Tokumasu, S., 1961. The maintenance and collapse of polyploidy in the progenies of autotetraploid Japanese radish, with reference to the occurrence of aneuploid plants. Mem. Ehime Univ. VI. 7: 177–349.Google Scholar
  20. Tokumasu, S., 1976. The increase of seed fertility of Brassicoraphanus through cytological irregularity. Euphytica 25: 463–470.Google Scholar

Copyright information

© Veenman B.V., Wageningen 1983

Authors and Affiliations

  • M. Kato
    • 1
  • S. Tokumasu
    • 1
  1. 1.College of AgricultureEhime UniversityMatsuyamaJapan

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