Skip Navigation


AOBPreview originally published online on February 26, 2009
Annals of Botany 2009 103(7):1005-1014; doi:10.1093/aob/mcp034
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow ContentSelect
Right arrow All Versions of this Article:
103/7/1005    most recent
mcp034v1
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 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 arrowRequest Permissions
Google Scholar
Right arrow Articles by Thorogood, C. J.
Right arrow Articles by Hiscock, S. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Thorogood, C. J.
Right arrow Articles by Hiscock, S. J.
Agricola
Right arrow Articles by Thorogood, C. J.
Right arrow Articles by Hiscock, S. J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?


© The Author 2009. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Host-specific races in the holoparasitic angiosperm Orobanche minor: implications for speciation in parasitic plants

C. J. Thorogood1,*, F. J. Rumsey2 and S. J. Hiscock1,*

1 School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
2 Department of Botany, Natural History Museum, Cromwell Road, London SW7 5BD, UK

* For correspondence. E-mail Simon.Hiscock{at}bristol.ac.uk or Christopher.Thorogood{at}bristol.ac.uk

Received: 19 October 2008    Returned for revision: 3 December 2008    Accepted: 9 January 2009    Published electronically: 26 February 2009

Background and Aims: Orobanche minor is a root-holoparasitic angiosperm that attacks a wide range of host species, including a number of commonly cultivated crops. The extent to which genetic divergence among natural populations of O. minor is influenced by host specificity has not been determined previously. Here, the host specificity of natural populations of O. minor is quantified for the first time, and evidence that this species may comprise distinct physiological races is provided.

Methods: A tripartite approach was used to examine the physiological basis for the divergence of populations occurring on different hosts: (1) host–parasite interactions were cultivated in rhizotron bioassays in order to quantify the early stages of the infection and establishment processes; (2) using reciprocal-infection experiments, parasite races were cultivated on their natural and alien hosts, and their fitness determined in terms of biomass; and (3) the anatomy of the host–parasite interface was investigated using histochemical techniques, with a view to comparing the infection process on different hosts.

Key Results: Races occurring naturally on red clover (Trifolium pratense) and sea carrot (Daucus carota ssp. gummifer) showed distinct patterns of host specificity: parasites cultivated in cross-infection studies showed a higher fitness on their natural hosts, suggesting that races show local adaptation to specific hosts. In addition, histological evidence suggests that clover and carrot roots vary in their responses to infection. Different root anatomy and responses to infection may underpin a physiological basis for host specificity.

Conclusions: It is speculated that host specificity may isolate races of Orobanche on different hosts, accelerating divergence and ultimately speciation in this genus. The rapid life cycle and broad host range of O. minor make this species an ideal model with which to study the interactions of parasitic plants with their host associates.

Key words: Parasitic plant, Orobanche, speciation, divergence, host-specificity, host-specific races


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 2009 103: i. [Extract] [Full Text]  

John Bryant takes a closer look at some of this month's Original Articles
J. A. Bryant
Ann Bot 2009 103: iii. [Extract] [Full Text]  





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.