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Kew Bulletin

, Volume 68, Issue 4, pp 599–607 | Cite as

Karyotypes in Ethiopian Aloe species (Xanthorrhoeaceae: Asphodeloideae)

  • Eshetu FentawEmail author
  • Kifle Dagne
  • Nina Rønsted
  • Sebsebe Demissew
  • Olwen M. Grace
Article

Summary

A cytogenetic survey of 17 species in the succulent-leaved genus Aloe L. (Xanthorrhoeaceae subfamily Asphodeloideae) in Ethiopia was undertaken towards a more complete genetic characterisation of the genus throughout its distribution in Africa, Arabia and Madagascar. Somatic metaphase chromosomes of all species studied showed the same diploid chromosome number of 2n = 14, consisting of four pairs of long and three pairs of short chromosomes. Symmetry was characterised as Stebbins type 2B and the asymmetry indices AsK%, TF%, A1 and A2 revealed minor karyotypic variation common in closely related species. The metrics showed that A. benishangulana has a marginally higher degree of asymmetry than is typical, and the pubescent-flowered A. trichosantha has a more symmetrical karyotype than most other species. We suggest that the stable karyotype morphology in Aloe indicates that structural genome changes and ecological factors play a more prominent role in speciation in Aloe.

Key words

chromosome cytology ecology genome speciation 

Notes

Acknowledgements

EF would like to express thanks to the staff of the Microbial, Cellular and Molecular Biology Program Unit and National Herbarium of Ethiopia (ETH) at the University of Addis Ababa for their assistance.

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Copyright information

© The Board of Trustees of the Royal Botanic Gardens, Kew 2013

Authors and Affiliations

  • Eshetu Fentaw
    • 1
    Email author
  • Kifle Dagne
    • 2
  • Nina Rønsted
    • 3
  • Sebsebe Demissew
    • 4
  • Olwen M. Grace
    • 3
    • 5
  1. 1.Department of BiologyWachemo UniversityHossanaEthiopia
  2. 2.Faculty of Life SciencesAddis Ababa UniversityAddis AbabaEthiopia
  3. 3.Botanic Garden & HerbariumNatural History Museum of DenmarkCopenhagen KDenmark
  4. 4.National Herbarium, Faculty of Life SciencesAddis Ababa UniversityAddis AbabaEthiopia
  5. 5.Jodrell LaboratoryRoyal Botanic Gardens, KewRichmondUK

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