Document Detail

Sex determination and the evolution of dioecy from monoecy in Sagittaria latifolia (Alismataceae).
MedLine Citation:
PMID:  15058400     Owner:  NLM     Status:  MEDLINE    
The role of mutations of small versus large effect in adaptive evolution is of considerable interest to evolutionary biologists. The major evolutionary pathways for the origin of dioecy in plants (the gynodioecy and monoecy-paradioecy pathways) are often distinguished by the number of mutations involved and the magnitude of their effects. Here, we investigate the genetic and environmental determinants of sex in Sagittaria latifolia, a species with both monoecious and dioecious populations, and evaluate evidence for the evolution of dioecy via gynodioecy or monoecy-paradioecy. We crossed plants of the two sexual systems to generate F1, F2 and backcross progeny, and grew clones from dioecious populations in low-and high-fertilizer conditions to examine sex inconstancy in females and males. Several lines of evidence implicate two-locus control of the sex phenotypes. In dioecious populations sex is determined by Mendelian segregation of alleles, with males heterozygous at both the male- and female-sterility loci. In monoecious populations, plants are homozygous for alleles dominant to male sterility in females and recessive to female sterility in males. Experimental manipulation of resources revealed sex inconstancy in males but not females. These results are consistent with predictions for the evolution of dioecy via gynodioecy, rather than the expected monoecy-paradioecy pathway, given the ancestral monoecious condition.
Marcel E Dorken; Spencer C H Barrett
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Proceedings. Biological sciences / The Royal Society     Volume:  271     ISSN:  0962-8452     ISO Abbreviation:  Proc. Biol. Sci.     Publication Date:  2004 Jan 
Date Detail:
Created Date:  2004-04-02     Completed Date:  2004-04-30     Revised Date:  2010-09-21    
Medline Journal Info:
Nlm Unique ID:  101245157     Medline TA:  Proc Biol Sci     Country:  England    
Other Details:
Languages:  eng     Pagination:  213-9     Citation Subset:  IM    
Department of Botany, University of Toronto, 25 Willcocks Street, Toronto, Ontario MSS 3B2, Canada.
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MeSH Terms
Crosses, Genetic
Genetics, Population*
Infertility / genetics
Models, Genetic*
Reproduction / physiology
Sagittaria / physiology*
Sex Determination (Genetics)*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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