The mechanism of sex determination in Rumex acetosella


Cytogenetic studies were made with particular emphasis on the sex-determining mechanism in Rumex acetosella (6 x = 42) and its hybrids (F 1, F 2, BC 1 and BC 2) with R. hastatulus (synthetic 4 x = 16 = 4 A +4 X = ♀ and 4 x = 18 = 4 A + 2 (X Y 1 Y 2) = ♂). Rumex acetosella was almost strictly dioecious with 50∶50 male and female. Breeding tests revealed that the males were heterogametic. The longest chromosomes (S), usually two, are the sex chromosomes of this hexaploid species. The S chromosomes are homomorphic in both male and female. The sex chromosome: autosome ratios, and the strong epistatic male effect of the S M chromosome in the polyploid dioecious species and in the hybrids, are evidence of an X/Y Melandrium type sex-determining mechanism controlled by a single pair of homomorphic sex chromosomes. Thus, the sex chromosome formula of the males was S F S M and that of females was S F S F. The present approach is a new method for resolving the sex-determining mechanism in a dioecious species.

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  1. 1.

    Burnham, C. R.: Discussions in Cytogenetics. Minneapolis: Burgess Publ. Co. 1962.

    Google Scholar 

  2. 2.

    Goldschmidt, R. B.: Theoretical Genetics. Berkeley: Univ. of California Press 1955.

    Google Scholar 

  3. 3.

    Löve, A.: Cytogenetic studies on Rumex subgenus Acetosella. Hereditas 30, 1–136 (1944).

    Google Scholar 

  4. 4.

    Löve, A., Sarkar, N.: Cytotaxonomy and sex determination of Rumex paucifolius. Can. Journ. Bot. 34, 261–268 (1956).

    Google Scholar 

  5. 5.

    Muller, H. J.: Why polyploidy is rarer in animals than in plants. Amer. Nat. 59, 346–353 (1925).

    Google Scholar 

  6. 6.

    Ono, T.: Further investigations on the cytology of Rumex. VI-VIII. Bot. Mag. Tokyo 44, 168–176 (1930).

    Google Scholar 

  7. 7.

    Ono, T.: Chromosomen und Sexualität von Rumex acetosa. Tohoku Imperial Univ., Science Reports, Ser. 4, 10, 41–210 (1935).

    Google Scholar 

  8. 8.

    Singh, R. B.: Cytogenetic studies in Rumex acetosella and its hybrids with R. hastatulus with special consideration of sex determination. Ph. D. Thesis, North Carolina State University (1964).

  9. 9.

    Singh, R. B.: A dioecious polyploid in Rumex acetosella. J. Heredity 59, 168–170 (1968).

    Google Scholar 

  10. 10.

    Smith, Ben W.: The mechanism of sex determination in Rumex hastatulus. Genetics 48, 1265 to 1288 (1963).

    Google Scholar 

  11. 11.

    Smith, Ben W.: Cytogeography and cytotaxonomic relationships of Rumex paucifolius. Am. J. Bot. 55, 673–683 (1968).

    Google Scholar 

  12. 12.

    Warmke, H. E.: Sex determination and sex-balance in Melandrium. Amer. J. Bot. 33, 648–660 (1946).

    Google Scholar 

  13. 13.

    Westergaard, M.: Studies on polyploidy and sex determination in polyploid forms of Melandrium album. Dansk Bot. Arkive 10 (5), 1–131 (1940).

    Google Scholar 

  14. 14.

    Westergaard, M.: The mechanism of sex determination in dioecious flowering plants. Advan. Genet. 9, 217–281 (1958).

    Google Scholar 

  15. 15.

    Yamamoto, Y.: Karyogenetische Untersuchungen bei der Gattung Rumex. VI. Geschlechtsbestimmung Rumex acetosa L. Kyoto Imperial Univ., Mem. Coll. Agr. 43, 1–59 (1938).

    Google Scholar 

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Communicated by M. S. Swaminathan

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Singh, R.B., Smith, B.W. The mechanism of sex determination in Rumex acetosella . Theoret. Appl. Genetics 41, 360–364 (1971).

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  • Present Approach
  • Cytogenetic Study
  • Single Pair
  • Dioecious Species
  • Male Effect