Abstract Detail

Population Genetics

Martine, Chris [1], Roche, Morgan [2], Boni, Alexandra [3], Jordon-Thaden, Ingrid [1].

Australian Solanum: A model system for evaluating genetic variability in populations of dioecious taxa compared to potentially selfing congeners in sympatry.

As obligate outcrossers, populations of dioecious plants might be more likely to avoid the perils of inbreeding than populations of self-fertilizing species. One way to test this hypothesis would be to compare representative populations in sympatry. The ca. 15 functionally dioecious species of Solanum in northern Australia represent a useful model for examining the potential genetic benefits of dioecy because a) Populations are often small and isolated from other conspecific populations, b) Populations are sympatric with hermaphroditic and andromonoecious (and potentially self-fertilizing) congeners, and c) Dioecy appears to be a recently-derived condition evidenced by retention of vestigial and/or non-functional reproductive organs. The present study employs ddRADtag with double digestion followed by Illumina sequencing to compare genetic variation within and among regionally sympatric populations of five Solanum species across three breeding systems: three dioecious species, a hermaphroditic species, and an andromonoecious species. Twenty populations and approximately 400 total individuals were analyzed. Where dioecious species are shown to have high intra- and meta-population genetic variability relative to self-fertilizing species, dioecy may represent an effective mechanism for avoiding inbreeding and maintaining genetic diversity. In contrast, where dioecious species show reduced genetic variability, low-density population structure and isolation of populations may be limiting gene migration, thus negating some of the potential benefits of the dioecious habit. This latter possibility has implications for conservation of functionally dioecious solanums in Australia, many of which are narrowly endemic and/or uncommon.

1 - Bucknell University, Biological Sciences, 203 Biology Building, Lewisburg, PA, 17837, USA, 570/577-1135
2 - Bucknell University, Biology C/o C. Martine, 1 Dent Drive, Lewisburg, PA, 17837, USA
3 - Bucknell University, Biology Dept, Biology Bldg 203, Lewisburg, PA, 17837, USA

Keywords:
population genetics
conservation genetics
ddRADtag
Solanum
solanaceae
Australia
dioecy
andromonoecy
outcrossing
inbreeding
selfing.

Presentation Type: Oral Paper:Papers for Topics
Session: 71
Location: Salon 6/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 2:30 PM
Number: 71005
Abstract ID:689
Candidate for Awards:None