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New chromosome counts inStreptocarpus (Gesneriaceae) from Madagascar and the Comoro Islands and their taxonomic significance

Abstract

This study records the chromosome numbers of 10 species ofStreptocarpus; nine of the counts are new. With the exception ofS. buchananii of mainland Africa, all the results are for plants endemic to Madagascar and the Comoro Islands. While there is a strong correlation between basic number and growth form in the two subgenera of the genus on the African mainland (x = 15 among caulescent species in subgenusStreptocarpella; x = 16 among acaulescent species in subgenusStreptocarpus), the situation appears more complex among Madagascan and Comoro Island species. One notable example of deviation from this correlation is shown byS. papangae, a shrubby caulescent species, with 2n = 32 (x = 16). Polyploidy in the genus appears to be absent on mainland Africa, but is present in Madagascar and the Comoro Islands, ranging from tetraploidy to octoploidy. Evolutionary implications of the cytological observations are considered.

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References

  1. Darlington C. D. (1937) Recent Advances in Cytology. Churchill, London.

    Google Scholar 

  2. Fox D. P. (1969) Some characterisitics of the cold hydrolysis technique for staining plant tissues by the Feulgen reaction. J. Histochem. Cytochem. 17: 226.

    Google Scholar 

  3. Gatt M., Ding H., Hammett K., Murray B. (1998) Polyploidy and evolution in wild and cultivatedDahlia species. Ann. Bot. 81: 647–656.

    Google Scholar 

  4. Halda J. (1989) Four new intergeneric hybrids in the family Gesneriaceae. Preslia 61: 125–127.

    Google Scholar 

  5. Hilliard O. M., Burtt B. L. (1971)Streptocarpus: an African plant study. University of Natal Press, Pietermaritzburg.

    Google Scholar 

  6. Humbert H. (1971) Gesnériacées, fam. 180 in Flore de Madagascar, Leroy J. F. ed. Paris.

  7. Jong K. (1970) Developmental aspects of vegetative morphology inStreptocarpus. PhD dissertation, Univ. of Edinburgh.

  8. Jong K. (1973)Streptocarpus (Gesneriaceae) and the phyllomorph concept. Acta Bot. Neerl. 22: 244–245.

    Google Scholar 

  9. Jong K. (1978) Phyllomorphic organisation in rosulateStreptocarpus. Notes Roy. Bot. Gard. Edinburgh 36: 369–396.

    Google Scholar 

  10. Jong K. (1997) Laboratory manual of plant cytological techniques, Royal Botanic Garden Edinburgh, Edinburgh. Wirobound, 87pp.

  11. Jong K., Burtt B. L. (1975) The evolution of morphological novelty exemplified in the growth patterns of some Gesneriaceae. New Phytol. 75: 297–311.

    Google Scholar 

  12. Kiehn M., Hellmayr E., Weber A. (1997) Chromosome numbers of Malayan and other paleotropical Gesneriaceae. I. Tribe Didymocarpeae. Beitr. Biol. Pflanzen 70: 407–444.

    Google Scholar 

  13. Lawrence W. J. C. (1931) Secondary association in polyploids. Cytologia 2: 252–284.

    Google Scholar 

  14. Lawrence W. J. C. (1940) The genusStreptocarpus. J. Roy. Hort. Soc. 65: 17–22.

    Google Scholar 

  15. Lawrence W. J. C., Scott-Moncrieff R., Sturgess V. C. (1939) Studies inStreptocarpus I. Genetics and chemistry of flower colour in the garden strains. J. Genet. 38: 299–306.

    Google Scholar 

  16. Milne C. (1975) Chromosome numbers in the Gesneriaceae: V. Notes Roy. Bot. Gard. Edinburgh 33: 523–525.

    Google Scholar 

  17. Möller M., Cronk Q. C. B. (1997) Origin and relationships ofSaintpaulia (Gesneriaceae) based on ribosomal DNA internal transcribed spacer (ITS) sequences. Amer. J. Bot. 84: 956–965.

    Google Scholar 

  18. Möller M., Cronk Q. C. B. (1999) Evolution of morphological novelty: a phylogenetic analysis of growth patterns inStreptocarpus (Gesneriaceae). Evolution (in press).

  19. Möller M., Clokie M., Cubas P., Cronk Q. C. B. (1999) Integrating molecular phylogenies and developmental genetics: a Gesneriaceae case study. In: Hollingsworth P. M., Bateman R. M., Gornall R. J. (eds.) Molecular systematics and plant evolution. Taylor & Francis, London pp. 375–402.

    Google Scholar 

  20. Oehlkers F. (1940) Bastardierungsversuche in der GattungStreptocarpus Lindley. III. Neue Ergebnisse über die Genetik von Wuchsgestalt und Geschlechtsbestimmung. Ber. Deutsch. Bot. Ges. 58: 76–91.

    Google Scholar 

  21. Ratter J. A. (1975) A survey of chromosome numbers in the Gesneriaceae of the Old World. Notes Roy. Bot. Gard. Edinburgh 33: 527–543.

    Google Scholar 

  22. Ratter J. A., Prentice H. T. (1967) Chromosome numbers in the Gesneriaceae. III. Notes Roy. Bot. Gard. Edinburgh 27: 205–209.

    Google Scholar 

  23. Ratter J. A., Milne C. (1970) Chromosome numbers in the Gesneriaceae: IV. Notes Roy. Bot. Gard. Edinburgh 30: 183–187.

    Google Scholar 

  24. Riley R. (1960) Secondary pairing of bivalents with genetically similar chromosomes. Nature 185: 751–752.

    Google Scholar 

  25. Skog L. (1984) A review of chromosome numbers in the Gesneriaceae. Selbyana 7: 252–273.

    Google Scholar 

  26. Smith J. F., Kresge M. E., Möller M., Cronk Q. C. B. (1998) A cladistic analysis ofndhF sequences from representative species ofSaintpaulia andStreptocarpus sectionsStreptocarpus andStreptocarpella (Gesneriaceae). Edinb. J. Bot. 55: 1–11.

    Google Scholar 

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Jong, K., Möller, M. New chromosome counts inStreptocarpus (Gesneriaceae) from Madagascar and the Comoro Islands and their taxonomic significance. Pl Syst Evol 224, 173–182 (2000). https://doi.org/10.1007/BF00986341

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Key words

  • Gesneriaceae
  • Streptocarpus
  • Chromosome numbers
  • growth patterns
  • taxonomy
  • Africa
  • Comoro Islands
  • Madagascar