Abstract Detail

Developmental and Structural Section

MARTINE , CHRISTOPHER T [1], Anderson, Gregory J. [2], Jordon-Thaden, Ingrid [3], Gilman, Ian [4].

Leakiness may be an insurance policy for functionally dioecious Solanum of oceanic and terrestrial islands.

Dioecy has arisen at least five times in Solanum, each time presenting as a functional system in which a) individual staminate plants produce flowers with functional stamens and nonfunctional gynoecia, and b) pistillate plants produce flowers with a functional gynoecium and stamens bearing non-functional inaperturate pollen, or no pollen. Thus, both functionally pistillate flowers and functionally staminate flowers are morphologically hermaphrodite, the gynoecia in the latter case being vestigial. Hundreds of controlled crosses and careful analysis of pollen have heretofore yielded no evidence of functionally hermaphrodite flowers (where both a gynoecium is fully developed and porate pollen is produced) in these species. However, three dioecious species in cultivation at the University of Connecticut (S. polygamum) and Bucknell University (S. asymmetriphyllym and S. sejunctum) have exhibited rare instances of “leaky dioecy” in which staminate plants produce hermaphrodite flowers that produce porate pollen and functional gynoecia with the occasional capacity to set fruit/seeds. While this has not been observed in wild populations, the occasional ability for staminate individuals to “cheat” and produce seeds, by autogamy if necessary, could play a critical role in establishing populations following the colonization of novel habitats by small numbers of individuals. This may be especially important in the species studied.  Solanum polygamum is a Caribbean island endemic, while S. asymmetriphyllum and S. sejunctum are restricted to isolated Australian sandstone outcrops that function much like terrestrial islands. 

1 - Bucknell University, Biological Sciences, 203 Biology Building, Lewisburg, PA, 17837, USA
2 - University Of Connecticut, Department Of Ecology & Evolutionary Biology, 75 N. Eagleville Road, Unit 43, Storrs, CT, 06269-3043, USA
3 - Bucknell University, Biology, 1 Dent Drive, Lewisburg, PA, 17837, USA
4 - Bucknell University, Dept Biology, Biology Bldg 203, Lewisburg, PA, 17837, USA

Keywords:
dioecy
Inaperturate pollen
Solanum
Solanaceae
floral development
Islands
colonization.

Presentation Type: Oral Paper:Papers for Sections
Session: 25
Location: Pines North/Boise Centre
Date: Tuesday, July 29th, 2014
Time: 10:30 AM
Number: 25002
Abstract ID:202
Candidate for Awards:None