Skip Navigation


AOBPreview originally published online on November 15, 2007
Annals of Botany 2008 101(1):25-30; doi:10.1093/aob/mcm275
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Supplementary Data
Right arrow All Versions of this Article:
101/1/25    most recent
mcm275v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in Ann Bot
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (7)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Besnard, G.
Right arrow Articles by Vargas, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Besnard, G.
Right arrow Articles by Vargas, P.
Agricola
Right arrow Articles by Besnard, G.
Right arrow Articles by Vargas, P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?


© The Author 2007. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Polyploidy in the Olive Complex (Olea europaea): Evidence from Flow Cytometry and Nuclear Microsatellite Analyses

G. Besnard1,*, C. Garcia-Verdugo2,3, R. Rubio De Casas2,3, U. A. Treier4,{dagger}, N. Galland1 and P. Vargas2

1 Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland
2 Royal Botanic Garden of Madrid, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain
3 Departamento de Biología Vegetal 1, UCM, José Antonio Novais 2, 28040 Madrid, Spain
4 University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland

* For correspondence. E-mail gbesnard{at}unil.ch

Received: 23 January 2007    Returned for revision: 15 May 2007    Accepted: 11 September 2007    Published electronically: 15 November 2007

Background: Phylogenetic and phylogeographic investigations have been previously performed to study the evolution of the olive tree complex (Olea europaea). A particularly high genomic diversity has been found in north-west Africa. However, to date no exhaustive study has been addressed to infer putative polyploidization events and their evolutionary significance in the diversification of the olive tree and its relatives.

Methods: Representatives of the six olive subspecies were investigated using (a) flow cytometry to estimate genome content, and (b) six highly variable nuclear microsatellites to assess the presence of multiple alleles at co-dominant loci. In addition, nine individuals from a controlled cross between two individuals of O. europaea subsp. maroccana were characterized with microsatellites to check for chromosome inheritance.

Key Results: Based on flow cytometry and genetic analyses, strong evidence for polyploidy was obtained in subspp. cerasiformis (tetraploid) and maroccana (hexaploid), whereas the other subspecies appeared to be diploids. Agreement between flow cytometry and genetic analyses gives an alternative approach to chromosome counting to determine ploidy level of trees. Lastly, abnormalities in chromosomes inheritance leading to aneuploid formation were revealed using microsatellite analyses in the offspring from the controlled cross in subsp. maroccana.

Conclusions: This study constitutes the first report for multiple polyploidy in olive tree relatives. Formation of tetraploids and hexaploids may have played a major role in the diversification of the olive complex in north-west Africa. The fact that polyploidy is found in narrow endemic subspecies from Madeira (subsp. cerasiformis) and the Agadir Mountains (subsp. maroccana) suggests that polyploidization has been favoured to overcome inbreeding depression. Lastly, based on previous phylogenetic analyses, we hypothesize that subsp. cerasiformis resulted from hybridization between ancestors of subspp. guanchica and europaea.

Key words: Flow cytometry, hexaploidy, High Atlas, Macaronesia, Olea europaea, olive, SSR, tetraploidy

{dagger} Present address: University of Aarhus, Department of Biological Sciences, Systematic Botany, Ny Munkegade, Building 1540, DK-8000 Aarhus, Denmark.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?

Related articles in Ann Bot:

ContentSnapshots

Ann Bot 2008 101: NP. [Extract] [Full Text]  



This article has been cited by other articles:


Home page
 ANN BOT (LOND)Home page
G. Besnard, R. Rubio de Casas, P.-A. Christin, and P. Vargas
Phylogenetics of Olea (Oleaceae) based on plastid and nuclear ribosomal DNA sequences: Tertiary climatic shifts and lineage differentiation times
Ann. Bot., July 1, 2009; 104(1): 143 - 160.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.