Abstract Detail

Frontiers in fern gametophyte research

Testo, Weston [1], Grasso, Matthew [1], Barrington, David [1].

Exploring patterns of gender-biased hybridization in the Polypodium virginianum complex: reconciling DNA sequence data and gametophyte breeding systems.

Interspecific hybridization is an important evolutionary mechanism in plants, especially in ferns, which are thought to possess less complex isolation mechanisms than angiosperms. Numerous studies have demonstrated differences in the strength of isolation mechanisms between reciprocal crosses of hybridizing species, resulting in biases in gametic contribution of each parental species; however, ecological factors associated with this pattern of gender bias in ferns remain understudied. The eastern North American members of the Polypodium virginianum complex present an excellent system in which to assess the natural occurrence of gender bias and the extent to which it is determined by gametophyte reproductive biology. In eastern North America, the diploid Polypodium appalachianum and the allotetraploid P. virginianum have broadly sympatric ranges, and the sterile triploid backcross P. x incognitum is frequently formed. Little is known about the dynamics of hybridization in this complex, including the degree of gender bias involved. We used sequence data from a chloroplast DNA marker (rpl32-trnL) to infer gender bias present in natural populations of P. x incognitum in northwestern Vermont. Gametophyte ecology and reproductive biology of both P. appalachianum and P. virginianum were studied to develop a comprehensive understanding of the influence of different gametophyte breeding systems on the outcome of hybridization events. This work is the most comprehensive study on gender-biased hybridization in ferns and highlights the importance of gametophyte reproductive biology to evolutionary trajectories.

Broader Impacts:

1 - University of Vermont, Plant Biology, 111 Jeffords Hall, 63 Carrigan Dr., University of Vermont, Burlington, Vermont, 05405, United States

Keywords:
fern
gametophyte
hybrid
antheridiogen
reproductive biology
mating system.

Presentation Type: Symposium or Colloquium Presentation
Session: C4
Location: Prince of Wales/Riverside Hilton
Date: Tuesday, July 30th, 2013
Time: 10:45 AM
Number: C4009
Abstract ID:98
Candidate for Awards:None