Abstract Detail

Hybrids and Hybridization

Kerbs, Benjamin [1], Crawford, Daniel J. [2], Mort, Mark [3].

Phenotypic novelty and the potential for speciation via stabilization of hybrid recombinants in Tolpis (Asteraceae).

The generation of phenotypic novelty and the origin of new species via stabilization of hybrid derivatives at the same ploidy level as the parents is a notably rare form of speciation called homoploid hybrid speciation (HHS). The genus Tolpis has a center of distribution in the islands of Macaronesia (Canary Islands, Azores, Cape Verde and Madeira) and is an appropriate system for studying the potential for HHS. Tolpis species endemic to the Canary Islands have the capacity to hybridize and have varying levels of selfing, a condition that could promote reproductive isolation of derivative taxa from their progenitors. Hybrids were synthesized by initially crossing T. coronopifolia, a self-compatible species, and T. santosii, an outcrossing species. There was segregation for morphological characters, pollen fertility, and self-seed set within each of 12 F₄ inbred lines, and also divergence between some lines. Additionally, transgressive characters were noted in some instances. Correlations were found among vegetative characters and among floral characters, but a decoupling between the two was evident. Based on rapid phenotypic divergence among several hybrid lines and on the apparent emergence of post-zygotic reproductive isolating mechanisms between some lines, it is suggested that homoploid hybrid speciation is feasible in Canary Island Tolpis, and that it may have played some role in the radiation and evolution of Tolpis in the Canary Islands.

1 - Emporia State University, Department of Biology, 1 Kellogg Circle, Campus Box 4050, Emporia, KS, 66801-5415, USA
2 - University Of Kansas, Department Of Ecology And Evolutionary Biology, 1200 Sunnyside Avenue, Haworth Hall, Lawrence, KS, 66045-7534, USA
3 - University of Kansas, Ecology and Evolutionary Biology and Biodiversity Institute, 1200 Sunnyside Ave, Lawrence, KS, 66045, USA

Keywords:
homoploid hybridization
Tolpis
Morphometrics.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PHB001
Abstract ID:227
Candidate for Awards:None