Abstract Detail

The evolutionary causes and consequences of dioecy across the land plants

Jesson, Linley [1], Garnock-Jones, Philip [2], Perley, Danielle [1].

The influence of ploidy on sexual systems evolution in bryophytes.

Land plants (bryophytes, seedless vascular plants and seed plants) may have combined or separate sexes, and this variation also may occur at two life-cycle stages. D.G. Lloyd’s classification of flowering plant gender can be extended to all land plants, with three main functional classes according to whether populations are dimorphic or monomorphic for gender (i.e. populations consist of either one or two distinct sex classes), and at which life cycle stages this occurs. Under this classification populations can be: 1) dimorphic at both stages (e.g, dioecious angiosperms), 2) sporophyte-cosexual & gametophyte-dimorphic (e.g., cosexual angiosperms and dioecious mosses), and 3) cosexual at both stages (e.g., cosexual mosses and ferns). An extended suite of model plants with different biological attributes will allow new tests of existing models of mechanisms that select for different sexual systems, and may lead to important new questions in the field. For example, in bryophytes gametophyte-dioecy is likely ancestral with frequent reversions to cosexuality, often associated with polyploidy. In this talk I focus on our studies of the bryophyte genus Atrichum which in which there are at least two independent origins of hermaphroditism, both associated with polyploidy events. We are currently using the variation in sexual system and gender that exists in Atrichum to ask questions about the roles of recombination and masking in influencing sexual system and sex chromosome evolution.

Broader Impacts:

1 - University of New Brunswick, Biology, 10 Bailey Dr, Fredericton, NB, E3B5A3, Canada
2 - VICTORIA UNIVERSITY OF WELLINGTON, SCHOOL OF BIOLOGICAL SCIENCES, PO BOX 600, Wellington, N/A, 6140, New Zealand

Keywords:
dioecy
Polyploidy
plant mating systems.

Presentation Type: Symposium or Colloquium Presentation
Session: SY05
Location: Jasperwood/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 2:15 PM
Number: SY05002
Abstract ID:389
Candidate for Awards:None