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Inflorescence and floral development in Streptocarpus and Saintpaulia (Gesneriaceae) with particular reference to the impact of bracteole suppression

Abstract

Floral development and inflorescence structure within Streptocarpus and Saintpaulia were investigated using Scanning Electron Microscopy (SEM). We discuss the structure and development of the pair-flowered cyme and the floral ontogeny found in the Gesneriaceae in a phylogenetic context with particular reference to an East African clade of Streptocarpus and Saintpaulia. Current phylogenetic hypotheses divide the caulescent East African Streptocarpus species into two distinct clades, in relation to which the position of Saintpaulia is not yet clear. Variation in the branching of the inflorescence showed phylogenetic significance and included dichasial, monochasial and unbranched patterns. In four of the East African Streptocarpus species sampled a single lateral bracteole was present on the first to third axes, after which the inflorescence was ebracteolate. Our results indicate that there may be some link between bracteole suppression and an alteration in the order of sepal initiation. The loss or suppression of lateral bracteoles also appears to result in the precocious development of the lateral cyme meristem.

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References

  • Harrison C. J. (1998) Developmental genetics and evolution of plant form in Streptocarpus. MSc thesis, University of Edinburgh, Edinburgh, UK.

  • C. J. Harrison M. Möller Q. C. B. Cronk (1999) ArticleTitleEvolution and Development of floral diversity in Streptocarpus and Saintpaulia Ann. Bot. 84 49–60 Occurrence Handle10.1006/anbo.1999.0887

    Article  Google Scholar 

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

    Google Scholar 

  • L. Hufford (1995) ArticleTitlePatterns of ontogenetic evolution in perianth diversification of Besseya (Scrophulariaceae) Amer. J. Bot. 82 IssueID5 655–680 Occurrence Handle10.2307/2445424

    Article  Google Scholar 

  • D. R. Maddison W. P. Maddison (2000) MacClade, version 4.0 Sinauer Associates Sunderland, Massachusetts

    Google Scholar 

  • M. Möller Q. C. B. Cronk (1997) ArticleTitleOrigin and relationships of Saintpaulia (Gesneriaceae) based on ribosomal DNA internal transcribed spacer (ITS) sequences Amer. J. Bot. 84 IssueID7 956–965 Occurrence Handle10.2307/2446286

    Article  Google Scholar 

  • Möller M., Cronk Q. C. B. (2001a) Evolution of morphological novelty: a phylogenetic analysis of growth patterns in Streptocarpus (Gesneriaceae). Evolution 55(5): 918–929.

    Google Scholar 

  • Möller M., Cronk Q. C. B. (2001b) Phylogenetic studies in Streptocarpus (Gesneriaceae): reconstruction of biogeographic history and distribution patterns. Syst. Geogr. Pl. 71: 545–555.

    Google Scholar 

  • J. F. Smith J. C. Wolfram K. D. Brown C. L. Carroll D. S. Denton (1997) ArticleTitleTribal relationships in the Gesneriaceae: evidence from DNA sequences of the chloroplast gene ndhF Ann. Missouri Bot. Gard. 84 IssueID1 50–66 Occurrence Handle10.2307/2399953

    Article  Google Scholar 

  • J. F. Smith M. E. Kresge M. Möller Q. C. B. Cronk (1998) ArticleTitleA cladistic analysis of ndhF sequences from representative species of Saintpaulia and Streptocarpus subgenera Streptocarpus and Streptocarpella (Gesneriaceae) Edinburgh J. Bot. 55 IssueID1 1–11 Occurrence Handle10.1017/S0960428600004315

    Article  Google Scholar 

  • K. K. Smith (2001) ArticleTitleHeterochrony revisited: the evolution of developmental sequences Biol. J. Linn. Soc. 73 IssueID2 169–186 Occurrence Handle10.1006/bijl.2001.0535

    Article  Google Scholar 

  • K. K. Smith (2003) ArticleTitleTime's arrow: heterochrony and the evolution of development Int. J. Dev. Biol. 47 IssueID7–8 613–621 Occurrence Handle14756337

    PubMed  Google Scholar 

  • Y. Z. Wang (2001) ArticleTitleReversion of floral development under adverse ecological conditions in Whytockia bijieensis (Gesneriaceae) Austral. J. Bot. 49 IssueID2 253–258 Occurrence Handle10.1071/BT00002

    Article  Google Scholar 

  • Y. Z. Wang Z. Y. Li (2002) ArticleTitleInflorescence development of Whytockia (Epithemateae, Gesneriaceae) and phylogenetic implications within Gesneriaceae Pl. Syst. Evol. 236 IssueID1–2 45–54 Occurrence Handle10.1007/s00606-002-0234-9

    Article  Google Scholar 

  • A. Weber (1973) ArticleTitleDie Struktur der paarblütigen Partialfloreszenzen der Gesneriaceen und bestimmter Scrophulariaceen Beitr. Biol. Pflanzen 49 IssueID3 429–460

    Google Scholar 

  • A. Weber (1978) ArticleTitleTransitions from pair-flowered to normal cymes in Gesneriaceae Notes Roy. Bot. Gard. Edinburgh 36 IssueID2 355–368

    Google Scholar 

  • A. Weber (1982) ArticleTitleEvolution and radiation of the pair-flowered cyme in Gesneriaceae Austral. Syst. Bot. Soc. Newsl. 30 23–41

    Google Scholar 

  • A. Weber (1995) ArticleTitleDevelopmental aspects of the pair-flowered cyme of Gesneriaceae Gesneriana 1 IssueID1 18–28

    Google Scholar 

  • Weber A. (2004) Gesneriaceae. In: Kubitzki K., Kadereit J. W. (eds.) The families and genera of vascular plants. Springer Berlin, pp. 63–158.

  • H. Wiehler (1983) ArticleTitleA synopsis of the neotropical Gesneriaceae Selbyana 6 IssueID1–4 1–219

    Google Scholar 

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Haston, E., De Craene, L. Inflorescence and floral development in Streptocarpus and Saintpaulia (Gesneriaceae) with particular reference to the impact of bracteole suppression. Plant Syst. Evol. 265, 13–25 (2007). https://doi.org/10.1007/s00606-006-0494-x

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  • DOI: https://doi.org/10.1007/s00606-006-0494-x

Keywords

  • Streptocarpus
  • Saintpaulia
  • Gesneriaceae
  • Floral development
  • Ontogeny
  • Initiation sequence
  • SEM