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Inheritance of resistance to mammalian herbivores and of plant defensive chemistry in an Eucalyptus species
journal contribution
posted on 2023-05-16, 16:12 authored by Julianne O'Reilly-WapstraJulianne O'Reilly-Wapstra, Bradley PottsBradley Potts, McArthur, C, Noel DaviesNoel Davies, Paul TilyardPaul TilyardHybridization in plants provides an opportunity to investigate the patterns of inheritance of hybrid resistance to herbivores, and of the plant mechanisms conferring this resistance such as plant secondary metabolites. We investigated how inter-race differences in resistance of Eucalyptus globulus to a generalist mammalian herbivore, Trichosurus vulpecula, are inherited in their F1 hybrids. We assessed browsing damage of 3-year-old trees in a common environment field trial on four hybrid types of known progeny. The progeny were artificial intra-race crosses and reciprocal inter-race F1 hybrids of two geographically distinct populations (races) of E. globulus north-eastern Tasmania and south-eastern Tasmania. Populations of trees from north-eastern Tasmania are relatively susceptible to browsing by T. vulpecula, while populations from south-eastern Tasmania are more resistant. We assessed the preferences of these trees in a series of paired feeding trials with captive animals to test the field trial results and also investigated the patterns of inheritance of plant secondary metabolites. Our results demonstrated that the phenotypic expression of resistance of the inter-race F1 hybrids supported the additive pattern of inheritance, as these hybrids were intermediate in resistance compared to the pure parental hybrids. The expression of plant secondary metabolites in the F1 hybrids varied among major groups of individual compounds. The most common pattern supported was dominance towards one of the parental types. Together, condensed tannins and essential oils appeared to explain the observed patterns of resistance among the four hybrid types. While both chemical groups were inherited in a dominant manner in the inter-race F1 hybrids, the direction of dominance was opposite. Their combined concentration, however, was inherited in an additive manner, consistent with the phenotypic differences in browsing.
History
Publication title
Journal of Chemical EcologyVolume
31Pagination
357-375ISSN
0098-0331Department/School
School of Natural SciencesPublisher
Plenum USPlace of publication
United StatesRights statement
?© 2005 Springer Science+Business Media, Inc.Repository Status
- Restricted