Abstract Detail

Genetics Section

Caton, Tara [1], Jordon-Thaden, Ingrid [2], Martine, Chris [2].

Morphological and Molecular Analysis of Solanum asymmetriphyllum × S. sejunctum Interspecific Hybrids.

Botanists have recognized problematic species boundaries among the functionally dioecious spiny solanums of northern Australia for decades. Of the ca. 15 species in this group, the Northern Territory sandstone endemic Solanum asymmetriphyllum stood out as the most morphologically distinct until its sister species, S. sejunctum was described in 2006. While molecular work has confirmed that each of these two taxa deserve individual recognition as species, our group recently found that interspecific crosses done in cultivation led to fruit and seed set, and that hybrid seeds were germinable and capable of generating reproductive F1 individuals. This study investigates these hybrid offspring with the goal of describing the morphological and genetic similarities of the interspecific hybrid offspring to either of the two parent species. Methods of comparison include morphometric analysis of vegetative and floral characteristics, a species-determining restriction enzyme digestion pattern assay of the gene SPOROPOLLENIN, flow cytometry of leaf tissue for ploidy level determination, and use of Genomic in situ Hybridization (GISH). Hand-pollinations were performed on reproductively mature F1 plants both within the hybrid offspring and back crosses to the parents, with preliminary results suggesting that hybrid breakdown occurs at this stage. The ability for the two species to form hybrid offspring suggests that they are recently diverged; and some outcomes of the study infer that the speciation of S. sejunctum may have occurred as a result of a single population becoming geographically isolated during periods of climate change.

1 - Bucknell University, Biology, One Dent Drive, Lewisburg, PA, 17837, USA
2 - Bucknell University, Biological Sciences, 203 Biology Building, Lewisburg, PA, 17837, USA, 570/577-1135

Keywords:
Solanum
solanaceae
hybrids
morphology
Australia
dioecy.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PGN013
Abstract ID:913
Candidate for Awards:Genetics Section Poster Award