Can hybridization cause local extinction : the case for demographic swamping of the Australian native, Senecio pinnatifolius, by the invasive, S. madagascariensis?


Autoria(s): Prentis, Peter; White, Evelyn; Radford, Ian J.; Lowe, Andrew J.; Clarke, Anthony R.
Data(s)

2007

Resumo

The outcome of interspecific hybridization between native and invasive species depends on the relative frequencies of parental taxa and viability of hybrid progeny. We investigated individual and population level consequences of hybridization between the Australian native, Senecio pinnatifolius, and the exotic S. madagascariensis, with AFLP markers and used this information to simulate the expected outcome of hybridization.A high frequency (range 8.3-75.6 %) of hybrids was detected in open pollinated seeds of both species, but mature hybrids were absent from sympatric populations indicating that sympatric populations represent tension zones. A hybridization advantage was observed for S. madagascariensis,where significantly more progeny than expected were sired based on proportional representation of the two species in sympatric populations. Simulations indicated S. pinnatifolius could be replaced in sympatric populations if hybridization was density dependent.For this native-exotic pair, prezygotic isolating barriers are weak, but low hybrid viability maintains a strong postzygotic barrier to introgression. Due to asymmetric hybridization, S. pinnatifolius appears under threat from demographic swamping, and local extinction is possible where it occurs in sympatry with S. madagascariensis.

Formato

application/pdf

Identificador

http://eprints.qut.edu.au/40148/

Publicador

Wiley-Blackwell Publishing Ltd

Relação

http://eprints.qut.edu.au/40148/1/c40148.pdf

DOI:10.1111/j.1469-8137.2007.02217.x

Prentis, Peter, White, Evelyn, Radford, Ian J., Lowe, Andrew J., & Clarke, Anthony R. (2007) Can hybridization cause local extinction : the case for demographic swamping of the Australian native, Senecio pinnatifolius, by the invasive, S. madagascariensis? New Phytologist, 176(4), pp. 902-912.

Direitos

Copyright 2007 Wiley-Blackwell Publishing Ltd

Fonte

Faculty of Science and Technology

Palavras-Chave #060202 Community Ecology #060207 Population Ecology #060208 Terrestrial Ecology #Amplified fragment length polymorphism (AFLP) #hybridization #hybrid viability #demographic swamping #invasive species #triploid
Tipo

Journal Article