HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

(American Journal of Botany. 2008;95:1297-1306.) doi: 10.3732/ajb.0800187 © 2008 Botanical Society of America, Inc.

What's this?

This Article Full Text Full Text (PDF) Supplementary Data Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Volz, S. M. Articles by Renner, S. S. Search for Related Content PubMed Articles by Volz, S. M. Articles by Renner, S. S. Agricola Articles by Volz, S. M. Articles by Renner, S. S. Social Bookmarking                            What's this?

Hybridization, polyploidy, and evolutionary transitions between monoecy and dioecy in Bryonia (Cucurbitaceae)¹

Department of Biology, Ludwig-Maximilians-University Munich, Menzinger Strasse 67, D-80638 Munich, Germany

ABSTRACT

Correns’s 1903 (Berichte der Deutschen Botanischen Gesellschaft 21: 133–147) crosses between a monoecious and a dioecious species of Bryonia revealed the simple Mendelian inheritance of dioecy and provided the first instance of an XY sex determination system in any organism. Bryonia ranges from the Canary Islands to Central Asia and comprises seven dioecious and three monoecious species; its closest relative, Ecballium elaterium, has dioecious and monoecious populations. We used chloroplast (cp) and nuclear (nr) gene phylogenies to infer sexual system evolution in Bryonia. We also tested for associations between sexual system and ploidy level, based on published and original chromosome counts. Conflicts between cp and nr topologies imply that the dioecious hexaploid B. cretica arose from hybridization(s), probably involving the dioecious diploids B. dioica, B. syriaca, and/or B. multiflora. A tetraploid dioecious endemic on Corsica and Sardinia probably originated from B. dioica via autopolyploidy. While the cp phylogeny resolves few species relationships, the nr tree implies at least two evolutionary changes in sexual system. There is no correlation between sexual system and ploidy level. Molecular clocks suggest that the deepest divergence, between a species on the Canary Islands and the ancestor of all remaining species, occurred ca. 10 million years ago.

Key Words: Bryonia • chloroplast DNA haplotypes • chromosome counts • Cucurbitaceae • dioecy • hybridization • monoecy • nuclear LEAFY intron • polyploidy

Received for publication 5 June 2008. Accepted for publication 22 July 2008.

FOOTNOTES

¹ The authors thank O. Tal and H. S. Paris for tubers and seeds of B. syriaca; the colleagues listed in online supplemental Appendix S1 for leaf material; D. Egamberdiyeva for hospitality in Uzbekistan; M. Pingen for information on fossil seeds; E. Vosyka for help with chromosome counts; S. Raidl for help with stomata measurements; G. Brokamp for the map; and R. Oyama, H. Schaefer, C. Jeffrey, and an anonymous reviewer for comments on earlier versions of this manuscript. Supported by DFG RE603/4-1.

² Author for correspondence (e-mail: renner{at}lrz.uni-muenchen.de)

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				H. Schaefer, C. Heibl, and S. S Renner Gourds afloat: a dated phylogeny reveals an Asian origin of the gourd family (Cucurbitaceae) and numerous oversea dispersal events Proc R Soc B, March 7, 2009; 276(1658): 843 - 851. [Abstract] [Full Text] [PDF]